U.S. patent application number 10/693764 was filed with the patent office on 2004-07-22 for spraygun with built-in quick-fit connector.
Invention is credited to Adams, Michael J. R., Delbridge, Neil, Howcroft, Michael W., Joseph, Stephen C. P..
Application Number | 20040140373 10/693764 |
Document ID | / |
Family ID | 32180211 |
Filed Date | 2004-07-22 |
United States Patent
Application |
20040140373 |
Kind Code |
A1 |
Joseph, Stephen C. P. ; et
al. |
July 22, 2004 |
Spraygun with built-in quick-fit connector
Abstract
A spray gun and a detachable liquid reservoir releasably
attached to the spray gun by engagement of mateable, non-threaded
formations provided on the spray gun and the reservoir. The spray
gun has an integral connector boss with a socket for reception of a
connector tube of the reservoir. The boss has an external flange at
the distal end and the reservoir has hook members separate from the
connector tube. The hook members are co-operable with the flange
when the connector tube is received in the socket to secure
releasably the reservoir to the spray gun. In another arrangement,
the connector tube is an interference friction-fit in the socket to
secure releasably the reservoir to the spray gun. In yet another
arrangement, the connector tube has bayonet lugs co-operable with
bayonet grooves in the wall of the socket when the connector tube
is received in the socket to secure releasably the reservoir to the
spray gun. In a still further arrangement, the reservoir has an
integral spout received in the socket integral with the spray gun
and provided with a helical projection co-operable with the
underside of a radial lug externally of the socket to secure the
reservoir.
Inventors: |
Joseph, Stephen C. P.;
(Woodbury, MN) ; Adams, Michael J. R.;
(Snettisham, GB) ; Delbridge, Neil; (Atherstone,
GB) ; Howcroft, Michael W.; (Hudson, WI) |
Correspondence
Address: |
3M INNOVATIVE PROPERTIES COMPANY
PO BOX 33427
ST. PAUL
MN
55133-3427
US
|
Family ID: |
32180211 |
Appl. No.: |
10/693764 |
Filed: |
October 24, 2003 |
Current U.S.
Class: |
239/379 ;
239/290; 239/433; 239/600 |
Current CPC
Class: |
B05B 7/2478 20130101;
B05B 7/2408 20130101; B65D 41/0407 20130101; F16L 37/252 20130101;
B05B 7/2481 20130101; F16L 37/2445 20130101; F16L 37/248
20130101 |
Class at
Publication: |
239/379 ;
239/433; 239/600; 239/290 |
International
Class: |
B05B 001/28 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 24, 2002 |
GB |
0224698.1 |
Mar 12, 2003 |
GB |
0305614.0 |
May 14, 2003 |
GB |
0311014.5 |
Claims
What is claimed is:
1. A liquid spraying apparatus comprising a spray gun and a
reservoir for a liquid to be sprayed, the reservoir having an
outlet connectable to the spray gun to permit the liquid to be
withdrawn from the reservoir in use, and the spray gun having
integral connector means arranged for non-threaded engagement with
co-operating connector means on the reservoir by means of which the
reservoir is releasably secured to the spray gun.
2. The apparatus according to claim 1 wherein the spray gun has an
integral socket adapted for connection to an outlet from the
reservoir.
3. The apparatus according to claim 2 wherein the socket provides a
through bore leading to an inlet of the spray gun and the outlet
from the reservoir communicates with the inlet when the reservoir
is connected to the spray gun for delivering liquid to the spray
gun in use.
4. The apparatus according to claim 2 wherein the spray gun has a
body and the socket is recessed in the body of the spray gun.
5. The apparatus according to claim 2 wherein the spray gun has a
body and the socket is provided in a connector boss arranged to
project from the body of the spray gun.
6. The apparatus according to claim 5 wherein the connector boss is
formed integrally with the body of the spray gun.
7. The apparatus according to claim 5 wherein the connector boss is
formed separately from the body of the spray gun and permanently
secured thereto.
8. The apparatus according to claim 2 wherein the reservoir has an
outlet opening to a connector tube integral with the reservoir, and
the connector tube is received in the socket to connect the
reservoir to the spray gun.
9. The apparatus according to claim 8 wherein the reservoir and
spray gun are provided with mateable formations providing a
push-fit connection of the reservoir to the spray gun.
10. The apparatus according to claim 9 wherein the connector tube
and socket are tapered so that the connector tube is an
interference friction fit in the socket to retain the reservoir on
the spray gun.
11. The apparatus according to claim 8 wherein the reservoir and
spray gun are provided with mateable formations engageable with a
push-twist action that requires less than one complete turn of the
reservoir relative to the spray gun.
12. The apparatus according to claim 11 wherein the connector tube
and socket are provided with bayonet type formations engageable
within the bore of the socket.
13. The apparatus according to claim 11 wherein the spray gun and
reservoir are provided with mateable formations engageable
externally of the bore of the socket.
14. The apparatus according to claim 13 wherein the mateable
formations include an integral undercut retainer on the spray gun
body.
15. The apparatus according to claim 14 wherein the reservoir is
provided with an external rib on the connector tube co-operable
with the underside of the retainer externally of the socket to
secure releasably the reservoir and resist axial separation of the
connector tube from the socket.
16. The apparatus according to claim 15 wherein the rib has a
helical form so that the connector tube is displaced axially into
the socket by engagement of the rib with the lug.
17. The apparatus according to claim 16 wherein a stop is provided
to limit relative rotation and/or axial displacement of the
connector tube relative to the socket.
18. The apparatus according to claim 17 wherein the stop comprises
an abutment at one end of the rib.
19. The apparatus according to claim 17 wherein the stop comprises
a further rib axially spaced from the helical rib.
20. The apparatus according to claim 8 wherein a fluid-tight seal
is provided by interference fit of the connector tube in the
socket.
21. The apparatus according to claim 8 wherein the socket and/or
connector tube is/are provided with one or more sealing rings, for
example O-rings, arranged to provide a fluid-tight seal.
22. The apparatus according to claim 16 wherein a fluid tight seal
is provided by axial displacement of the connector tube causing an
end face of the connector tube to engage an internal sealing face
within the socket.
23. The apparatus according to claim 14 wherein the socket is
provided with an insert for providing the socket with a mateable
formation compatible with the mateable formation on the
reservoir.
24. The apparatus according to claim 23 wherein the insert is
provided with an external rib co-operable with the underside of the
retainer externally of the socket to secure releasably the insert
and resist axial separation of the insert from the socket.
25. The apparatus according to claim 24 wherein the rib has a
helical form so that the insert is displaced axially into the
socket by engagement of the rib with the lug.
26. The apparatus according to claim 25 wherein a stop is provided
to limit relative rotation and/or axial displacement of the insert
relative to the socket.
27. The apparatus according to claim 26 wherein the stop comprises
an abutment at one end of the rib.
28. The apparatus according to claim 26 wherein the stop comprises
a further rib axially spaced from the helical rib.
29. The apparatus according to claim 23 wherein the insert is
arranged to block the retainer externally of the socket.
30. The apparatus according to claim 23 wherein a fluid-tight seal
is provided by interference fit of the insert in the socket.
31. The apparatus according to claim 23 wherein the socket and/or
insert is/are provided with one or more sealing rings, for example
O-rings, arranged to provide a fluid-tight seal.
32. The apparatus according to claim 25 wherein a fluid tight seal
is provided by axial displacement of the insert causing an end ace
of the insert to engage an internal sealing face within the
socket.
33. The apparatus according to claim 23 wherein the insert is a
nylon moulding.
34. The apparatus according to claim 23 wherein a set of
interchangeable inserts is provided allowing fitment of any
selected one of the inserts to provide the socket with any desired
connector formation.
35. The apparatus according to claims 2 wherein a sidewall of the
reservoir defines an opening at one end of the reservoir that forms
the outlet and the end of the sidewall is received in the socket of
the spray gun to connect the reservoir to the spray gun.
36. The apparatus according to claim 34 wherein the socket has an
annular seat engageable with the end of the sidewall around the
opening.
37. The apparatus according to claim 36 wherein the end of the
sidewall is located and retained in the socket by an interference
push-fit in the socket to secure releasably the reservoir.
38. The apparatus according to claim 36 wherein the sidewall and
socket are provided with complementary non-threaded connector
formations to secure releasably the reservoir.
39. The apparatus according to claim 1 wherein the reservoir is
re-usable.
40. The apparatus according to claim 39 wherein the reservoir
comprises a rigid pot that is removable from the spray gun and can
be cleaned on completion of spraying.
41. The apparatus according to claim 40 wherein the pot has an
openable air vent at the end remote from the connection to the
spray gun to allow air to enter as liquid is withdrawn from the pot
in use.
42. The apparatus according to claim 1 wherein the reservoir is
provided with a disposable container that can be thrown away after
use.
43. The apparatus according to claim 42 wherein the reservoir
comprises an outer container and an inner container, the inner
container being collapsible as liquid is withdrawn from the
reservoir and separate from the outer container so that the inner
container can be removed and thrown away after use.
44. The apparatus according to claim 43 wherein the outer container
has an air vent at the end remote from the connection to the spray
gun to allow air to enter as liquid is withdrawn from the inner
container in use
45. A spray gun having a body provided with an integral socket for
connecting a reservoir provided with a mateable connector by push
fit or push-twist requiring less than one complete turn, and an
insert for converting the socket for connecting a reservoir
provided with a non-mateable connector.
46. The spray gun according to claim 45 wherein the spray gun body
and insert are provided with retainer formations co-operable
externally of the socket to resist axial separation of the insert
from the socket.
47. The spray gun according to claim 46 wherein one of the retainer
formations comprises a rib of helical form and the other retainer
formation comprises a projection co-operable with the rib to secure
releasably the insert to the spray gun.
48. The spray gun according to claim 47 wherein the rib provides a
ramp face that displaces the insert towards the spray gun in
response to relative rotation to secure the insert to the spray
gun.
49. The spray gun according to claim 45 wherein the insert is
arranged to convert the socket for threaded connection to the
reservoir.
50. A spray gun having an integral non-threaded connector for
mating engagement with a non-threaded connector on a reservoir to
connect releasably the reservoir to the spray gun.
51. The spray gun according to claim 50 wherein the non-threaded
connectors on the spray gun and reservoir comprise a socket on one
of the spray gun and reservoir adapted to receive a mating
connector on the other of the spray gun and reservoir.
52. The spray gun according to claim 51 wherein the socket is
provided on the spray gun and has an internal bore providing an
inlet connectable to an outlet of the reservoir.
53. The spray gun according to claim 52 wherein the outlet of the
reservoir is provided by a spout received in the bore of the socket
on the gun.
54. The spray gun according to claim 50 wherein connectors are
engageable within the bore of the socket to connect releasably the
reservoir to the gun.
55. The spray gun according to claim 50 wherein the connectors are
engageable externally of the bore of the socket to connect
releasably the reservoir to the gun.
56. The spray gun according to claim 55 wherein one of the
connectors is provided with a rib of helical form and the other
connector is provided with a projection co-operable with the rib to
secure releasably the reservoir to the spray gun.
57. The spray gun according to claim 56 wherein the rib provides a
ramp face that displaces the reservoir towards the spray gun in
response to relative rotation to secure the reservoir to the spray
gun.
58. The spray gun according to claim 45 comprising any one of a
gravity fed, suction fed or pressure fed spray gun.
59. A liquid spraying apparatus comprising a spray gun and a
reservoir for a liquid to be sprayed, the reservoir being
releasably connectable to the spray gun by means of a quick-fit
connector system employing mateable connectors on the spray gun and
reservoir wherein the spray gun has a body and the spray gun
connector is integral with the spray gun body.
60. The apparatus according to claim 59 wherein the spray gun and
reservoir define a connection axis when the reservoir is secured to
the spray gun.
61. The apparatus according to claim 60 wherein the mateable
connectors are engaged/disengaged by relative axial movement
substantially parallel to the connection axis.
62. The apparatus according to claim 60 wherein the mateable
connectors are engaged/disengaged by a combination of relative
axial movement substantially parallel to the connection axis and
angular movement about the connection axis.
63. A method of attaching a reservoir to a spray gun comprising
providing a body of the spray gun with an integral non-threaded
connector, providing the reservoir with a non-threaded connector
mateable with the connector of the body, and connecting the
connectors to secure releasably the reservoir to the spray gun.
64. The method according to claim 63 wherein the connectors are
engageable with a push-twist action requiring less than one
complete turn of the reservoir to secure the reservoir to the spray
gun.
Description
[0001] This application claims priority from GB Ser. No. 0224698.1,
filed Oct. 24, 2002, GB Ser. No. 0305614.0 filed Mar. 12, 2003, and
GB Ser. No. 0311014.5 filed May 14, 2003.
[0002] 1. Field of the Invention
[0003] This invention concerns improvements in or relating to
liquid spraying apparatus such as a spray gun. More especially, the
invention relates to the connection between the spray gun and a
reservoir containing the liquid to be sprayed. The invention has
particular, but not exclusive, application to a releasable
connection for detachably mounting the reservoir on the spray gun
and to a spray gun adapted for such connection.
[0004] 2. Background of the Invention
[0005] Spray guns are widely used in vehicle body repair shops when
re-spraying a vehicle that has been repaired following an accident.
In the known spray guns, the liquid is contained in a reservoir
attached to the gun from where it is fed to a spray nozzle. On
emerging from the spray nozzle, the liquid is atomised and forms a
spray with compressed air supplied to the nozzle. The liquid may be
gravity fed or suction fed or, more recently, pressure fed by an
air bleed line to the reservoir from the compressed air line to the
spray gun.
[0006] Traditionally, the liquid is contained in a rigid pot
mounted on the spray gun by engagement of complementary screw
threads on the pot and gun. In this way, the pot can be removed for
cleaning or replacement. Typically, the pot is secured to the gun
empty and has a removable lid by means of which the liquid can be
added to the pot while attached to the gun. On completion of
spraying, the pot can be removed and the gun and pot cleaned for
re-use.
[0007] With this arrangement, the threads on the gun and pot may be
damaged by mis-use, for example if an attempt is made to secure a
pot having a non-matching thread. Also, on completion of spraying,
careful cleaning is required to remove all traces of liquid from
the threads to prevent the threads becoming blocked, for example
with dried paint, and to prevent cross-contamination with the
liquid next sprayed.
[0008] Damaged or blocked threads may render the gun unusable
requiring the purchase of a new gun. This adds to costs and is
inconvenient if working time is lost because a spare gun is not to
hand to continue spraying. Moreover, cleaning of the threads
usually requires solvents that are also used to clean the gun and
pot. The use of solvents is undesirable from health and safety
considerations and causes problems for disposal of the solvent
after use.
[0009] We have recently developed a system in which the reservoir
is disposable after use thereby reducing the amount of cleaning
required on completion of spraying. With this system, the reservoir
may be filled with the liquid to be sprayed before attaching to the
gun. The traditional screw threaded connection requires the
reservoir to be rotated several times, typically at least four or
five turns, to engage fully the threads and secure the reservoir in
a fluid tight manner. This is time consuming and requires
considerable care and dexterity on the part of the user to prevent
spillage when the reservoir is full of liquid.
[0010] In order to reduce these problems we have proposed a system
for connecting the reservoir to the spray gun via an adaptor that
is screwed into the spray gun and provides a releasable quick-fit
connection to the reservoir. For example, the reservoir and adaptor
may be provided with bayonet type formations that are engageable
with a push-twist action requiring less than one complete turn of
the reservoir to connect the reservoir to the gun.
[0011] This arrangement enables the reservoir to be attached to and
detached from the gun in a simple, efficient manner that reduces
the risk of spillage when the reservoir contains liquid and that
requires less dexterity on the part of the user.
[0012] The provision of the adaptor enables existing guns having a
screw thread connection for use with a conventional rigid pot to be
converted for use with our system using a disposable reservoir.
This has numerous advantages for the user, in particular from the
reduced amount of cleaning required on completion of spraying.
However, problems can arise if an adaptor having a thread matching
the thread on the gun is not to hand, for example if the adaptor is
removed for cleaning and lost. The gun cannot then be used with the
disposable reservoir and working time may be lost if the user does
not have a spare adaptor or a rigid pot that can be screwed into
the spray gun without the adaptor. Also, the screw threaded
connection between the gun and adaptor is susceptible to damage
from mis-use in the same way as the connection between the gun and
pot that may result in the gun being unusable.
SUMMARY
[0013] The present invention has been made from a consideration of
the foregoing problems and disadvantages of the existing
arrangements for securing a reservoir to a spray gun.
[0014] More particularly, at least some embodiments of the present
invention provide an improved connection between a spray gun and
reservoir that enables the reservoir to be attached to and detached
from the gun in a simple manner that reduces the risk of damage to
the gun.
[0015] Furthermore, at least one embodiment of the present
invention provides such improved connection between the gun and
reservoir that allows the reservoir to be attached directly to the
gun without additional separate components that may be lost and/or
may not match the connections on the gun and reservoir.
[0016] Moreover, at least one embodiment of the present invention
provides a spray gun adapted for rapid, releasable connection to a
reservoir that enables the reservoir to be connected when filled
with liquid with less risk of spillage and does not require a high
degree of dexterity on the part of the user to connect/disconnect
the reservoir.
[0017] Additionally, at least one embodiment of the present
invention provides a spray gun provided with an integral connector
for detachably mounting a reservoir having a mateable connector,
and an adapter for converting the spray gun connector for
releasably mounting a reservoir provided with a non-mateable
connector in a simple manner.
[0018] Also, at least one embodiment of the present invention
provides a spray gun provided with an integral connector for
detachably mounting a reservoir that combines the functions of a
lid to close an open end of the reservoir and a fluid connector for
transferring liquid from the reservoir to the spray gun in use.
[0019] In addition, at least one embodiment of the present
invention provides an insert for converting an integral,
non-threaded connector socket on a spray gun for mounting a
reservoir having a connector that is non-mateable with the
connector socket and is compatible with the insert.
[0020] Thus, according to one aspect of the present invention,
there is provided liquid spraying apparatus comprising a spray gun
and a reservoir for a liquid to be sprayed, the reservoir having an
outlet connectable to the spray gun to permit the liquid to be
withdrawn from the reservoir in use, and the spray gun having
integral connector means arranged for non-threaded engagement with
co-operating connector means on the reservoir by means of which the
reservoir is releasably secured to the spray gun.
[0021] As used herein, the term "liquid" refers to all forms of
flowable materials that can be applied using a spray gun (whether
or not they are intended to colour the surface) including (without
limitation) paints, primers, base coats, lacquers, varnishes and
similar paint-like materials as well as other materials such as
adhesives, sealers, fillers, putties, powder coatings, blasting
powders, abrasive slurries, mould release agents and foundry
dressings which may be applied in atomised or non-atomised form
depending on the properties and/or the intended application of the
material and the term "liquid" is to be construed accordingly.
[0022] By this invention, the spray gun is provided with an
integral non-threaded connector for mating engagement with a
co-operating non-threaded connector on the reservoir. In this way,
the afore-mentioned problems and disadvantages of a screw-threaded
connection between the reservoir and spray gun are avoided and the
reservoir can be releasably secured to the spray gun in a simple
manner that facilitates rapid connection/disconnection of the
reservoir.
[0023] As used herein, the term "non-threaded engagement" refers to
all forms of releasable connection between two connectors that can
be engaged with/disengaged from each other either by relative axial
movement and/or by relative angular movement involving less than
one complete turn about a connection axis.
[0024] In a preferred arrangement, the spray gun has an integral
socket adapted for connection to an outlet from the reservoir. The
socket provides a through bore leading to an inlet of the spray gun
and the outlet from the reservoir communicates with the inlet in a
fluid-tight manner when the reservoir is connected to the spray gun
for delivering liquid to the spray gun in use.
[0025] The socket may be recessed in the body of the spray gun.
More preferably, however, the socket is provided in a connector
boss arranged to project from the body of the spray gun. In this
way, the socket is clear of the body of the spray gun providing
improved access for connection of the reservoir.
[0026] The connector boss may be formed integrally with the body of
the spray gun. For example, the body and boss may be a casting of
metal or alloy or a moulding. Alternatively, the connector boss may
be formed separately from the body of the spray gun and permanently
secured thereto. For example, the connector boss may be welded or
adhesively bonded to the body of the spray gun.
[0027] In one embodiment, the outlet from the reservoir opens to a
connector tube integral with the reservoir, and the connector tube
is received in the socket to connect the reservoir to the spray
gun. For example, the connector tube may be provided at one end of
the reservoir. In one arrangement, the reservoir has a removable
lid at one end provided with the connector tube.
[0028] The reservoir and spray gun may be provided with mateable
formations providing a push-fit connection of the reservoir to the
spray gun. For example, the connector tube and socket may be
tapered so that the connector tube is an interference friction fit
in the socket to retain the reservoir on the spray gun.
[0029] Alternatively, the reservoir and spray gun may be provided
with mateable formations engageable with a push-twist action that
requires less than one complete turn of the reservoir relative to
the spray gun.
[0030] In one arrangement, the connector tube and socket are
provided with bayonet type formations engageable within the bore of
the socket. For example, the connector tube may be provided with
one or more outwardly extending bayonet lugs or ears co-operable
with one or more bayonet grooves in the wall of the bore of the
socket. The or each bayonet groove may have an axially extending
guide portion to receive the aligned lug or ear leading to a
circumferentially extending retention portion to trap and retain
the lug or ear to secure the reservoir to the spray gun.
[0031] In another arrangement, the spray gun and reservoir are
provided with mateable formations engageable externally of the bore
of the socket. For example, the reservoir may be provided with one
or more hook members separate from the connector tube and arranged
to engage the spray gun to secure releasably the reservoir and
resist axial separation of the connector tube from the socket.
[0032] The or each hook member is preferably locatable over a
surface of an external flange of the connector boss. For example,
the flange may have a recess arranged to pass the distal end of the
aligned hook member, and an adjacent cam lobe arranged to deflect
resiliently the hook member on rotation of the reservoir to cause
the distal end of the hook member to locate over the surface of the
flange to retain the reservoir on the spray gun.
[0033] The flange may be provided with a stop so that rotation of
the reservoir relative to the spray gun to secure the reservoir is
restricted to less than 360 degrees. For example, the stop may
provide a quick-fit connection employing a half or quarter turn of
the reservoir relative to the spray gun. The stop may comprise an
abutment face engaged by the or each hook member.
[0034] Alternatively, the reservoir may be provided with an
external rib on the connector tube co-operable externally of the
socket with the spray gun to secure releasably the reservoir and
resist axial separation of the connector tube from the socket. The
rib is preferably locatable under a radial lug or projection on the
spray gun by inserting the connector tube in the socket and
rotating the reservoir relative to the spray gun through less than
one complete turn. In a modification, the rib may be provided on
the spray gun and the lug on the connector tube.
[0035] The rib may have a helical form providing a ramp face
co-operable with the lug so that the connector tube is displaced
axially into the socket by engagement of the rib with the lug. The
rib and lug are arranged so that the reservoir can be secured to
the spray gun by rotation relative to the spray gun of less than
360 degrees. The rib may extend for approximately 180 degrees in a
circumferential direction.
[0036] Preferably, a stop is provided to restrict rotation of the
reservoir relative to the spray gun. In this way, over-tightening
of the connectors is prevented and axial movement of the connector
tube into the socket is controlled to ensure a fluid-tight
connection is achieved. The stop may comprise an abutment at one
end of the rib that is engageable with the lug to block rotation of
the reservoir relative to the spray gun. Alternatively, the stop
may comprise a second rib axially spaced from the helical rib that
is engageable with the lug or the spray gun body to block axial
movement of the connector tube into the socket.
[0037] A fluid-tight seal may be provided by interference fit of
the connector tube in the socket. The interference fit may be
assisted by the provision of one or more annular sealing ribs on
the connector tube. Alternatively, the socket and/or connector tube
may be provided with one or more sealing rings, for example
O-rings, arranged to provide a fluid-tight seal.
[0038] In another embodiment, a sidewall of the reservoir defines
an opening at one end of the reservoir that forms the outlet and
the end of the sidewall is received in the socket of the spray gun
to connect the reservoir to the spray gun. In this embodiment, the
connector boss of the spray gun may be provided with an enlarged
head that defines the socket and forms a lid for the reservoir.
[0039] In this way, the open end of the reservoir is closed when
the reservoir is connected to the spray gun and a separate,
detachable lid for the reservoir is not required. As a result, the
number of parts for assembly of the reservoir can be reduced and
the connection of the reservoir to the spray gun simplified.
[0040] In one arrangement, the socket preferably has an annular
seat engageable with the end of the sidewall around the opening.
The end of the sidewall may be located and retained in the socket
by an interference push-fit to secure releasably the reservoir in
the socket.
[0041] Alternatively, the sidewall and socket may be provided with
complementary non-threaded connector formations. The non-threaded
connector formations may comprise any of the arrangements described
previously, for example mateable formations engageable with a
push-twist action internally or externally of the socket such as
bayonet formations.
[0042] The reservoir may be re-usable. For example, the reservoir
may comprise a rigid pot that is removable from the spray gun and
cleaned on completion of spraying. Typically, the pot has an
openable air vent at the end remote from the connection to the
spray gun to allow air to enter as liquid is withdrawn from the pot
in use.
[0043] More preferably, the reservoir is disposable. For example,
the reservoir may comprise an outer container and an inner liner,
the liner being collapsible as liquid is withdrawn from the
reservoir and separate from the outer container so that the liner
can be removed and thrown away after use. Typically, the outer
container has an air vent at the end remote from the connection to
the spray gun to allow air to enter as liquid is withdrawn from the
liner in use
[0044] The above-described sockets on the spray gun may be provided
with an insert for converting the socket for connecting a reservoir
having a non-mateable connector. In this way, the spray gun can be
adapted to mount reservoirs provided with different connectors in a
simple, effective manner. A set of interchangeable inserts may be
provided allowing fitment of any selected one of the inserts to
provide the socket with any desired connector formation.
Preferably, the inserts are plastics mouldings but other materials
including metals may be used. Typically, the inserts are nylon
mouldings.
[0045] In one arrangement the spray gun is provided with an
integral retainer formation externally of the socket such that a
reservoir provided with a mateable retainer formation can be
located and secured to the spray gun by a push-twist action
requiring less than one complete turn of the reservoir relative to
the spray gun, and the inserts enable the spray gun to be adapted
to connect reservoirs provided with conventional screw threaded
connectors or other types of connector that are non-mateable with
the integral retainer formation on the spray gun.
[0046] The inserts may be provided with a retainer formation
mateable with that on the spray gun to locate and retain the
insert. For example, the inserts may be provided with an external
rib co-operable externally of the socket with the retainer
formation on the spray gun to secure releasably the insert and
resist axial separation of the insert from the socket.
[0047] The retainer formation may comprise a radial lug or
projection with the rib being locatable on the underside by placing
the insert in the socket and rotating the insert relative to the
spray gun through less than one complete turn. In this way, the
insert can be employed to locate and retain the reservoir and
prevent inadvertent or accidental separation of the reservoir from
the socket.
[0048] The rib may have a helical form providing a ramp face
co-operable with the lug so that the insert is displaced axially
into the socket by engagement of the rib with the lug. The rib and
lug are arranged so that the insert can be secured to the spray gun
by rotation relative to the spray gun of less than 360 degrees. The
rib may extend for approximately 180 degrees in a circumferential
direction. In a modification, the rib may be provided on the spray
gun and the lug on the insert.
[0049] Preferably, a stop is provided to restrict rotation of the
insert relative to the spray gun. In this way, over-tightening of
the connectors is prevented and axial movement of the insert into
the socket is controlled to ensure a fluid-tight connection is
achieved. The stop may comprise an abutment at one end of the rib
that is engageable with the lug to block rotation of the insert
relative to the spray gun. Alternatively, the stop may comprise a
second rib axially spaced from the helical rib that is engageable
with the lug or the spray gun body to block axial movement of the
insert into the socket.
[0050] Alternatively, the inserts may be arranged to block or
circumvent the integral retainer formation on the spray gun so that
it does not interfere with the connection to the reservoir. For
example, the insert may be provided with a recessed portion in
which the retainer formation on the spray gun is received by push
fit of the insert in the socket. The recessed portion may be
provided in a flange that is arranged to extend on either side of
the retainer formation to limit rotation of the insert relative to
the spray gun. In this arrangement, the insert is preferably an
interference fit in the socket to reduce the risk of inadvertent or
accidental separation of the insert (and attached reservoir) from
the socket.
[0051] The spray gun with integral non-threaded connector may also
have application for providing a connection to a remote reservoir
via a supply line, e.g. tubing, having an appropriate mateable
connector for connection to the socket or to an insert for
converting the socket to receive a non-mateable connector.
[0052] Thus, according to another aspect of the present invention,
there is provided a spray gun with an integral socket for
connecting a reservoir provided with a mateable connector and a
removable insert for converting the socket for connecting a
reservoir provided with a non-mateable connector.
[0053] The socket may be adapted for non-threaded connection to the
reservoir with the insert being arranged to convert the socket for
threaded connection to the reservoir.
[0054] According to yet another aspect of the present invention,
there is provided a spray gun having an integral non-threaded
connector for mating engagement with a non-threaded connector on a
reservoir to connect releasably the reservoir to the spray gun.
[0055] The non-threaded connectors on the spray gun and reservoir
may comprise a socket on one of the spray gun and reservoir adapted
to receive a mating formation on the other of the spray gun and
reservoir.
[0056] In one arrangement, the socket is provided on the spray gun
and has an internal bore providing an inlet connectable to an
outlet of the reservoir. In this arrangement, the outlet of the
reservoir may be provided by a connector tube received in the bore
of the socket on the spray gun.
[0057] The socket may be recessed in the body of the spray gun but
more preferably the spray gun has a connector boss that projects
from the body of the spray gun in which the socket is formed.
[0058] The connectors may be engageable within the bore of the
socket to connect releasably the reservoir to the gun.
Alternatively, the connectors may be engageable externally of the
bore of the socket to connect releasably the reservoir to the
gun.
[0059] According to a still further aspect of the present
invention, there is provided a method of attaching a reservoir to a
spray gun comprising providing a body of the spray gun with an
integral non-threaded connector, providing the reservoir with a
non-threaded connector mateable with the connector of the body, and
connecting the connectors to secure releasably the reservoir to the
spray gun.
[0060] Preferably, the connectors are engageable with a push-twist
action requiring less than one complete turn of the reservoir to
secure the reservoir to the spray gun. For example, the connectors
may be of the bayonet type.
[0061] According to a further aspect of the present invention there
is provided liquid spraying apparatus comprising a spray gun and a
reservoir for a liquid to be sprayed, the reservoir being
releasably connectable to the spray gun by means of a quick-fit
connector system employing mateable connectors on the spray gun and
reservoir wherein the spray gun has a body and the spray gun
connector is integral with the spray gun body.
[0062] Preferably, the spray gun and reservoir define a connection
axis when the reservoir is secured to the spray gun. The mateable
connectors may be engaged/disengaged by relative axial movement
substantially parallel to the connection axis. Alternatively, the
mateable connectors may be engaged/disengaged by a combination of
relative axial movement substantially parallel to the connection
axis and angular movement of less than 360 degrees about the
connection axis.
[0063] According to still yet another aspect of the present
invention there is provided liquid spraying apparatus comprising a
spray gun and a reservoir for a liquid to be sprayed, the reservoir
having a sidewall extending from a first end to a second end and
defining an opening at the first end, and the spray gun having an
integral inlet connector with an enlarged head co-operable with the
first end of the reservoir such that the opening is sealed in a
fluid-tight manner relative to the head.
[0064] The enlarged head of the inlet connector forms a lid for the
reservoir. In this way, the open end of the reservoir is closed
when the reservoir is connected to the spray gun and a separate,
detachable lid for the reservoir is not required. As a result, the
number of parts for assembly of the reservoir can be reduced and
the connection of the reservoir to the spray gun simplified.
[0065] In one arrangement, the head defines a socket to receive the
first end of the reservoir. The socket preferably has an annular
seat engageable with the first end of the reservoir around the
opening.
[0066] The first end of the reservoir may be located and retained
in the socket by a threaded or non-threaded connection. In one
arrangement, the socket and reservoir are provided with
complementary screw threads to secure releasably the reservoir. In
another arrangement, the reservoir is an interference push-fit in
the socket to secure releasably the reservoir. In yet another
arrangement, the reservoir and socket are provided with
complementary non-threaded connector formations engageable
internally or externally of the socket.
[0067] The inlet connector may be formed integrally with the spray
gun, for example by casting or moulding. Alternatively, the inlet
connector may be formed separately and permanently secured to the
spray gun, for example by welding or adhesive bonding.
[0068] The reservoir may comprise a rigid pot with an openable air
vent at the second end to allow air to enter as liquid is withdrawn
from the reservoir in use. More preferably, the reservoir comprises
an outer container and an inner liner, the liner being collapsible
as liquid is withdrawn from the reservoir and separate from the
outer container so that the liner can be removed and thrown away
after use.
[0069] Other features, benefits and advantages of the invention in
each of its aspects will be apparent from the following detailed
description of exemplary embodiments of the invention with
reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0070] FIG. 1 is a perspective view of liquid spraying apparatus
embodying the present invention;
[0071] FIG. 2 is a perspective view of the reservoir shown in FIG.
1 separate from the spray gun;
[0072] FIG. 3 is a longitudinal section through the reservoir shown
in FIG. 2;
[0073] FIG. 4 is a perspective view of the spray gun shown in FIG.
1 separate from the reservoir;
[0074] FIG. 5 is an exploded perspective view showing a detail of
the connection between the spray gun and reservoir shown in FIGS. 1
to 4;
[0075] FIG. 6 is an end view of the connector boss of the spray gun
with parts removed for clarity;
[0076] FIG. 7 is an exploded perspective view of an alternative
connection between a spray gun and reservoir embodying the present
invention;
[0077] FIG. 8 is a section through the assembled connection of FIG.
7;
[0078] FIG. 9 is an exploded perspective view of another connection
between a spray gun and reservoir embodying the present
invention;
[0079] FIG. 10 is a section through the spray gun socket shown in
FIG. 9;
[0080] FIG. 11 is a perspective view of a spray gun with an
alternative integral connector according to the invention;
[0081] FIG. 12 is a section, to an enlarged scale, showing a
reservoir attached to the integral connector of FIG. 11;
[0082] FIG. 13 is a section, similar to FIG. 12, showing a
modification to the reservoir;
[0083] FIG. 14 is a perspective view of a spray gun with an
integral connector according to the invention and a removable
insert for converting the connector to receive a threaded connector
for attaching a reservoir;
[0084] FIG. 15 is a perspective view showing a threaded connector
connected to the spray gun shown in FIG. 14;
[0085] FIG. 16 is a perspective view showing a reservoir connected
to the spray gun shown in FIGS. 14 and 15;
[0086] FIG. 17 is a section through the integral connector and
insert of the spray gun shown in FIG. 14 and showing the threaded
connector of FIG. 15 separate from the insert;
[0087] FIG. 18 is a perspective view of a spray gun showing a
modification to the connector of FIG. 11 according to another
aspect of the invention;
[0088] FIG. 19 is a section, to an enlarged scale, showing a
reservoir attached to the integral connector of FIG. 18;
[0089] FIG. 20 is a section through an inlet port in the body of a
gravity feed spray gun provided with an external retainer
formation;
[0090] FIG. 21 is a perspective view of an insert adapter for the
inlet port shown in FIG. 20;
[0091] FIG. 22 is a plan view of the insert adapter shown in FIG.
21;
[0092] FIG. 23 is a side view of the insert adapter shown in FIG.
21;
[0093] FIG. 24 is a sectional view of the insert adapter shown in
FIG. 21;
[0094] FIG. 25 shows the insert adapter of FIGS. 21 to 24 mounted
in the inlet port of the spray gun body shown in FIG. 20;
[0095] FIG. 26 is a perspective view of an alternative insert
adapter for the inlet port shown in FIG. 20;
[0096] FIG. 27 is a plan view of the insert adapter shown in FIG.
26;
[0097] FIG. 28 is a side view of the insert adapter shown in FIG.
26;
[0098] FIG. 29 is a sectional view of the insert adapter shown in
FIG. 26;
[0099] FIG. 30 is a perspective view of another insert adapter for
the inlet port shown in FIG. 20;
[0100] FIG. 31 is a plan view of the insert adapter shown in FIG.
30;
[0101] FIG. 32 is a side view of the insert adapter in the
direction of arrow A shown in FIG. 31;
[0102] FIG. 33 is a sectional view of the insert adapter shown in
FIG. 30;
[0103] FIG. 34 is a sectional view showing the insert adapter of
FIGS. 30 to 33 mounted in the inlet port of the spray gun body
shown in FIG. 20;
[0104] FIG. 35 is a perspective view of another insert adapter for
the inlet port shown in FIG. 20;
[0105] FIG. 36 is a plan view of the insert adapter shown in FIG.
35;
[0106] FIG. 37 is a side view of the insert adapter in the
direction of arrow B shown in FIG. 36;
[0107] FIG. 38 is a side view of the insert adapter in the
direction of arrow C shown in FIG. 36;
[0108] FIG. 39 is a sectional view of the insert adapter shown in
FIG. 35;
[0109] FIG. 40 is a perspective view of another insert adapter for
the inlet port shown in FIG. 20;
[0110] FIG. 41 is a plan view of the insert adapter shown in FIG.
40;
[0111] FIG. 42 is a side view of the insert adapter in the
direction of arrow D shown in FIG. 41;
[0112] FIG. 43 is a side view of the insert adapter in the
direction of arrow E shown in FIG. 41;
[0113] FIG. 44 is a sectional view of the insert adapter shown in
FIG. 40;
[0114] FIG. 45 is a perspective view of a reservoir with integral
spout adapted for connection to the spray gun of FIG. 20;
[0115] FIG. 46 is a side view of the reservoir shown in FIG.
45;
[0116] FIG. 47 is a longitudinal sectional view of the reservoir
shown in FIG. 45;
[0117] FIG. 48 is a perspective view of a reservoir lid with
integral spout adapted for connection to the spray gun of FIG.
20;
[0118] FIG. 49 is a side view of the reservoir lid shown in FIG.
48;
[0119] FIG. 50 is a longitudinal sectional view of the reservoir
lid shown in FIG. 48;
[0120] FIG. 51 is a side view showing a modification to the insert
of FIGS. 21 to 24; and
[0121] FIG. 52 is a side view showing a modification to the insert
of FIGS. 26 to 29.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0122] Referring first to FIG. 1 of the accompanying drawings,
there is shown liquid spraying apparatus embodying the present
invention comprising a gravity fed spray gun 1 and a reservoir 2
releasably connected to the spray gun 1.
[0123] The gun 1 comprises a body 3, a handle 4 which extends
downwards from the rear end of the body, and a spray nozzle 5 at
the front end of the body. The gun 1 is manually-operated by a
trigger 6 which is pivotally-mounted on the sides of the gun.
[0124] The reservoir 2, which contains paint (or similar material)
to be discharged by the gun, is located on the top of the body 3
and communicates with an internal passageway (not visible) which
extends through the gun to the nozzle 5.
[0125] In use, the gun 1 is connected via a connector 7 at the
lower end of the handle 4 to a source of compressed air (not shown)
so that, when the user pulls on the trigger 6, compressed air is
delivered through the gun to the nozzle 5. As a result, paint
delivered under gravity from the reservoir 2 to the nozzle 5 is
atomised on leaving the nozzle 5 and forms a spray with the
compressed air emerging from the nozzle 5.
[0126] Referring now to FIGS. 2 and 3 of the drawings, the
reservoir 2 includes an outer container 8, a disposable liner 9, a
disposable lid 10 and a collar 11. The liner 9 corresponds in shape
to (and is a close fit in) the interior of the container 8 and has
a narrow rim 12 at the open end which sits on the top edge of the
container 8.
[0127] The lid 10 is of conical shape and has a dependent skirt 13
inset from the peripheral edge. The skirt 13 is a push-fit in the
open end of the liner 9 to locate the peripheral edge of the lid 10
over the rim 12 of the liner 9. The lid/liner assembly is secured
in place by the annular collar 11 that screws onto the container 8
on top of the lid 10.
[0128] The lid 10 has a central aperture 14 at the apex that leads
to a connector tube 15 providing a fluid outlet and a pair of hook
member 16, 17 located either side of the connector tube 15. The
hook members 16, 17 are arranged to secure releasably the reservoir
2 to the spray gun 1 and the tube 15 is formed with external
annular ribs 18 to provide a fluid-tight seal with the spray gun 1
as described later.
[0129] A mesh filter 19 is a push-fit within the skirt 13 and
removes particulate material from the paint delivered through the
tube 15 to the spray gun 1 in use. Alternatively, the filter 19 may
be a push-fit in the tube 15 or may be an integral part of the lid
10.
[0130] With reference now to FIGS. 4 to 6, the spray gun 1 is
provided with an integral connector boss 20 on top of the body 3.
The boss 20 extends upwardly from the body 3 and has a socket 21
shaped to receive the connector tube 15 on the lid 10 of the
reservoir 2. The socket 21 terminates at an internal shoulder 33
leading to a bore 34 that extends away from the socket 21 and
provides an inlet for delivery of paint from the reservoir 2 to the
spray gun 1.
[0131] In this embodiment, the boss 20 is formed integrally with
the body 3 of the gun 1, for example, the body 3 may be a casting
of lightweight metal or alloy. Alternatively, the boss 20 may be
formed separately and permanently secured to the body 3, for
example by welding so as to form an integral part of the gun 1.
[0132] The external ribs 18 of the connector tube 15 provide a
fluid-tight seal with the socket 21 and the boss 20 has an external
flange 22 at the distal end for co-operating with the hook members
16, 17 to secure releasably the reservoir 2 to the spray gun 1. In
an alternative arrangement (not shown), a fluid-tight seal may be
obtained by one or more sealing rings, eg O-rings, located in
groove(s) on the connector tube 15 or in the wall of the socket
21.
[0133] The flange 22 comprises four arcuate recesses 23, 24, 25, 26
(FIG. 6) uniformly spaced in a circumferential direction around the
periphery such that the recesses 23, 25 are opposite each other and
the recesses 24, 26 are opposite each other. Each recess 23, 24,
25, 26 leads in a clockwise direction (as viewed in FIG. 6) via a
cam lobe 23a, 24a, 25a, 26a at the end of the recess 23, 24, 25, 26
to a flat 27, 28, 29, 30 that terminates in an abutment 27a, 28a,
29a, 30a.
[0134] Each hook member 16, 17 comprises an enlarged head 31, 32 at
the distal end having a chamfer face 31a, 32a leading to an
undercut locking rib 31b, 32b for co-operating with the flange
22.
[0135] To secure the reservoir 2 to the spray gun 1, the hook
members 16, 17 are aligned with a pair of opposed recesses 23, 25
or 24, 26 in the flange 22. The connector tube 15 is then pushed
into the socket 21 so that the enlarged heads 31, 32 of the hook
members 16, 17 pass through the aligned recesses 23, 25 or 24,
26.
[0136] The reservoir 2 is then rotated relative to the spray gun 1
to cause the hook members 16, 17 ride over the cam lobes 23a, 25a
or 24a, 26a and locate the locking ribs 31b, 32b behind the flats
27, 29 or 28, 30. Rotation of the reservoir 2 is restricted by
engagement of the hook members 16, 17 with the abutments 27a, 29a
or 28a, 30a.
[0137] In this way, the reservoir 2 can be secured to the spray gun
1 by a push-twist action requiring less than one complete turn of
the reservoir 2 relative to the spray gun 1 about a connection axis
defined by the engagement of the connector tube 15 in the socket
21. In this embodiment, the reservoir is rotatable through
approximately a quarter turn or less to secure the reservoir to the
spray gun.
[0138] The reservoir 2 can be removed from the spray gun 1 by a
reverse operation in which the reservoir 2 is first rotated to
align the enlarged heads 31, 32 of the hook members 16, 17 with the
opposed recesses 23, 25 or 24, 26. The reservoir 2 is then pulled
to withdraw the connector tube 15 from the socket 21.
[0139] The hook members 16, 17 are deflected outwardly by
engagement with the cam lobes 23a, 25a or 24a, 26a and snap back on
passing the cam lobes when rotating the reservoir 2 relative to the
spray gun 1 both to attach and detach the reservoir 2. In this way,
when attached to the spray gun 1, the reservoir 2 is positively
retained in position when the spray gun 1 is being manoeuvred to
apply paint to a surface.
[0140] The reservoir 2 can also be fitted to the spray gun 1 by a
simple push fit by first aligning the hook members 16, 17 with a
pair of opposed flats 27, 29 or 28, 30 of the flange 22. The
reservoir 2 is then pushed towards the spray gun 1 to cause the
chamfer faces 31a, 32a to engage the flange 22. The enlarged heads
31, 32 are deflected outwardly due to the resilience of the hook
members 16, 17 to ride over the flange 22 and snap back after
passing the flange 22 to locate the locking ribs 31b, 32b behind
the flats 27, 29 or 28, 30. In this way, the reservoir 2 is secured
to the spray gun 1. It may be possible to remove the reservoir 2 by
a reverse operation if sufficient force is applied to release the
locking ribs 31b, 32b.
[0141] In use, the reservoir 2 is filled with paint (or other
liquid to be sprayed) prior to mounting on the spray gun 1. For
this, the liner 9 is pushed inside the container 8. Paint is then
put into the liner 9 and, if necessary, mixed with other tinters,
hardeners and thinners (solvents). The lid 10 is then pushed into
place and the collar 11 is screwed down tightly to hold the lid 10
in position.
[0142] The spray gun 1 is then inverted from its normal operating
position illustrated in FIG. 1 so that the reservoir 2 can be
presented to the spray gun 1 in an upright position to prevent
spillage of paint. The reservoir 2 is then secured to the spray gun
1 by a push-twist or push action as described above.
[0143] The spray gun 1 can then be returned to its normal operating
position for use in the usual way. As paint is withdrawn from the
reservoir, the liner 9 collapses in an axial direction from base
end 9a towards the lid 10. A vent hole 8a in the base end of the
container 8 allows air to enter the container 8 as the liner 9
collapses. Sidewall 9b of the liner 9 folds inwardly in a random,
uncontrolled manner as the liner 9 collapses.
[0144] After use, when the spray gun 1 is to be cleaned, the spray
gun 1 can be re-inverted from its operating position shown in FIG.
1. The airline is disconnected and the trigger 6 actuated briefly
to allow paint within the spray gun 1 to drain back into the liner
9 in the reservoir 2. The reservoir 2 is then removed from the
spray gun 1 as described above.
[0145] As will be appreciated, the integral formations on the gun 1
and reservoir 2 enable the reservoir 2 to be attached to and
detached from the gun 1 by a simple action. In this way, the
apparatus can be rapidly and easily assembled and disassembled with
minimum manual dexterity on the part of the user. Also the risk of
spillage when connecting the reservoir 2 containing paint to the
gun 1 is reduced. Furthermore, the reservoir 2 can be detachably
secured to the gun 1 without a separate adaptor and without
engagement of screw threads that can be damaged by mis-use or
become blocked by deposits of paint so as to render the gun 1
unusable.
[0146] The reservoir 2 can be disassembled when disconnected from
the spray gun 1 by removing the collar 11 and pulling out the lid
10 bringing with it the collapsed liner 9. Any paint remaining in
the liner 9 may be stored for a short period of time by sealing the
connector tube 15, for example with a detachable closure cap (not
shown). The lid/liner assembly can then be re-assembled with the
container 8 and collar 11 and re-attached to the spray gun 1 to use
the remaining paint.
[0147] When removed from the container 8, the lid/liner assembly is
relatively fragile and susceptible to separation of the liner 9 and
lid 10 if mishandled. Accordingly, it is generally only practical
to store unused paint for a few hours and any unused paint must be
decanted into another container if long term storage is
required.
[0148] When all the paint has been used or if any remaining paint
is no longer required, the lid 10 (including the filter 19) and
collapsed liner 9 can be discarded leaving the container 8 and
collar 11 clean and ready for re-use with a fresh liner 9 and lid
10. In this way, only the spray gun 1 itself needs to be cleaned.
As a result, a reduction in the amount of solvent used for cleaning
may be achieved.
[0149] Referring now to FIGS. 7 and 8, there is shown another
arrangement for releasably securing the reservoir to the spray gun.
For convenience, like reference numerals in the series 100 are used
to indicate parts corresponding to the previous embodiment.
[0150] In this embodiment, the hook members of the previous
embodiment are omitted and the reservoir 102 is releasably secured
to the spray gun 101 by an interference friction fit between the
connector tube 115 of the reservoir 102 and the socket 121 of the
spray gun 101.
[0151] As shown, the connector tube 115 on the lid 110 of the
reservoir 102 is of conical shape tapered towards the distal end
and the socket 121 of the connector boss 120 is of conical tapered
shape for an interference friction fit of the tube 115 in the
socket 121. In this way, the reservoir 102 is secured to the gun
101 by push-fit.
[0152] The interference friction fit of the tube 115 provides a
fluid-tight seal with the socket 121. If desired, one or more
sealing rings (not shown) may be located in groove(s) in the tube
115 or socket 121 to enhance the seal therebetween. The or each
sealing ring is compressed by push-fit of the tube 115 that also
assists retention of the tube 115 in the socket 121.
[0153] In other respects, the construction of the reservoir 102 is
generally similar to the previous embodiments and will be
understood from the description thereof without further
explanation.
[0154] Referring now to FIGS. 9 and 10, there is shown yet another
arrangement for releasably securing the reservoir to the spray gun.
For convenience, like reference numerals in the series 200 are used
to indicate parts corresponding to the previous embodiments.
[0155] In this embodiment, the hook members of the embodiment of
FIGS. 1 to 6 are omitted and the reservoir is releasably secured to
the spray gun 201 by co-operating bayonet formations on the
connector tube 215 of the reservoir and the socket 221 of the spray
gun 201.
[0156] As shown, the connector tube 215 is provided at its distal
end with opposed outward extending lugs 250 forming one part of a
bayonet connection. The connector boss 220 of the spray gun 201 is
formed internally with the other part of the bayonet connection.
More particularly, the internal wall of the socket 221 is formed
with opposed inwardly facing grooves 251 extending axially from the
outer free end of the boss 220 and terminating at internal shoulder
233 in a circumferential groove 252.
[0157] In this way, the reservoir is secured to the spray gun 201
by aligning the lugs 250 with the axial grooves 251 and pushing the
connector tube 215 into the socket 221 until the distal end of the
tube 215 contacts the shoulder 233. The reservoir is then rotated
to locate the lugs 250 in the circumferential groove 252. In this
way, the reservoir is retained by the lugs 250. The reservoir can
be detached from the spray gun 201 by a reverse operation.
[0158] In other respects, the construction of the reservoir is
generally similar to the previous embodiments and will be
understood from the description thereof without further
explanation.
[0159] Referring first to FIGS. 11 and 12 of the accompanying
drawings, there is shown another arrangement for releasably
securing the reservoir to the spray gun. For convenience, like
reference numerals in the series 300 are used to indicate parts
corresponding to the previous embodiments.
[0160] In this embodiment, the spray gun 301 is provided with an
external connector boss 320 integral with the spray gun body 303.
The connector boss 320 extends upwardly from the top of the body
303 and has an enlarged annular head 360 defining a socket 321
shaped to receive the open end of a disposable liner 309 and an
outer container 308 for the liner 309.
[0161] The rim 312 of the liner 309 locates on an annular seat 361
within the socket 321 with an annular clearance gap 362 between the
sidewall 309b of the liner and the opposed sidewall 321b of the
socket.
[0162] The sidewall 321b of the socket 321 is smooth and tapers
slightly towards the base of the socket 321. The liner 309 is held
in place by push fit of the open end of the outer container 308 in
the clearance gap 362 to secure the rim 312 of the liner 309
between the seat 361 and the open end of the container 308. The
container 308 is retained by frictional engagement with the tapered
sidewall 321b of the socket 321 and ensures a fluid-tight seal
between the liner 309 and the socket 321.
[0163] Inwardly of the seat 361, the base of the socket 321 is of
conical shape and tapers towards a central opening to a bore 324 of
reduced diameter relative to the socket 321 that provides an inlet
for delivery of paint from the reservoir 302 to the spray gun 301.
In this way, paint flows towards the inlet and dead spaces where
paint may become trapped are avoided.
[0164] The bore 324 may contain a removable filter (not shown) for
filtering paint as it is withdrawn from the reservoir to remove any
solid particles. Alternatively or additionally, the paint may be
filtered when added to the reservoir 302.
[0165] In use, the outer container 308 can be stood upright on its
base and the liner 309 inserted in the open end to position the rim
312 over the open end. Paint or other liquid to be sprayed can be
added to the liner 309 and mixed therein.
[0166] The assembly of the liner 309 and container 308 can then be
presented to the socket 321 with the gun 301 in an inverted
position so that socket 321 is facing downwards and pushing the
open end of the assembly into the socket 321 to secure the outer
container 308 and seal the liner 309 relative to the socket
321.
[0167] The gun 301 can then be inverted to its normal upright
position for spraying with the liner 309 and container 308 being
held in place by the frictional engagement of the container 308 in
the socket 321. The liner 309 collapses as paint is withdrawn and
air is admitted to the interior of the container 308 through the
air hole 308a in the bottom of the container 308.
[0168] On completion of spraying, the assembly of the liner 309 and
container 308 can be detached from the gun 301 and the liner 309
thrown away. A new liner 309 can be fitted in the container 308 and
the assembly re-attached to the gun 301 after cleaning the paint
contaminated parts of the gun 301 to spray another paint or
liquid.
[0169] If there is any paint remaining in the liner 309 after
spraying, this may be stored in the liner 309 temporarily by
attaching a cap (not shown) to close the open end of the liner 309.
The cap can be removed and the assembly of the liner 309 and
container 308 re-attached to the spray gun 301 to use the
paint.
[0170] As will now be appreciated, by forming the connector boss
320 on the spray gun 301 with a socket 321 to receive the open end
of the liner 309 and by using the outer container 308 to secure the
liner 309 by push fit in the socket 321, the connector boss 320
effectively forms the lid of the reservoir 302.
[0171] In this way, the number of parts is reduced and assembly of
the reservoir 302 and connection to the spray gun 301 is
simplified. Also, on completion of spraying, only the liner 309 has
to be thrown away and replaced providing a potential cost saving
for the end user.
[0172] In a modification, shown in FIG. 13, the outer container 308
is replaced by a tubular sleeve 370 open at both ends allowing
liners 309a, 309b, 309c, 309d of different length to be secured
with a common connector sleeve 370. In this way, the volume of the
reservoir 302 can be varied according to the area to be sprayed by
selecting and fitting the appropriate size of liner 309a, 309b,
309c, 309d with the same connector sleeve 370 thereby reducing the
number of components required to fit reservoirs having a range of
volumes.
[0173] The sleeve 370 may be used with liners 309 that are
contained wholly or partly within the sleeve 370. Thus, in FIG. 13,
the sleeve 370 is shown to be longer than each of the liners 309a,
309b, 309c so that each liner 309a, 309b, 309c is protected and
supported over the whole of its length by the sleeve 370. This is
not essential, however, and the sleeve 370 is also shown in FIG. 13
to be shorter than liner 309d so that the liner 309d projects from
the free end of the sleeve 370 and is protected and supported over
part of its length only by the sleeve 370.
[0174] It will be understood that the socket 321 and container 308
may be provided with any suitable non-threaded connectors to secure
releasably the reservoir 302 to the connector boss 320. For
example, the socket 321 and container 308 may be provided with
co-operating bayonet formations or co-operating snap engageable
formations.
[0175] Moreover, it will be understood that the connector boss 320
may be used to attach a reservoir to the spray gun 301 that does
not have a liner 309. For example, the outer container 308 may have
a solid base provided with an openable air hole to allow air to
enter as paint is withdrawn.
[0176] Referring now to FIGS. 14 to 17 of the accompanying
drawings, there is shown another arrangement for releasably
securing the reservoir to the spray gun. For convenience, like
reference numerals in the series 400 are used to indicate parts
corresponding to the previous embodiments.
[0177] In this embodiment, the spray gun 401 is provided with an
integral connector boss 420 in the form of a socket 421 and a
separate detachable insert 480 for reception in the socket 421.
[0178] In certain embodiments the insert 480 is a plastics moulding
that is releasably secured in the socket 421 by push fit and has an
annular flange or collar 481 at the outer end that locates on the
rim of the socket 421. The insert 480 is retained in place by
friction.
[0179] It will be understood, however, that any suitable
non-threaded means may be provided to secure releasably the insert
480. For example the socket 421 and insert 480 may be provided with
co-operating bayonet formations or snap engageable formations.
[0180] The insert 480 has a through bore 482 with an internal screw
thread 483 for engagement of a complementary external thread 484 at
one end of a mating adaptor 485. The adaptor 485 has a through bore
(not shown) and is provided at the other end with an external
flange 422 for co-operating with hook members 416, 417 on the
reservoir 402 to secure releasably the reservoir 402 to the spray
gun 401.
[0181] The flange 422 and hook members 416, 417 are similar to the
parts shown in FIGS. 5 and 6 by means of which the reservoir 402
can be attached to and detached from the spray gun 401 as described
previously.
[0182] It will be understood, however, that the reservoir 402 and
adaptor 485 may be provided with any suitable complementary
co-operating formations to secure releasably the reservoir 402 to
the spray gun 401. For example co-operating bayonet formations or
snap engageable formations. Alternatively, the reservoir 402 and
adaptor 485 may have co-operating screw threads.
[0183] As will be apparent, the insert 480 converts the socket 421
to receive a screw threaded member for mounting the reservoir 402.
In this embodiment, the screw threaded member is a separate adaptor
485 to which the reservoir 402 is releasably secured. It will be
understood, however, that this is not essential and that the screw
threaded member could be an outlet of the reservoir that screws
directly into the insert 480 without requiring the adaptor 485.
[0184] The insert 480 is a separate component and can be removed
from the socket 421 if a threaded connection is not required to
connect a reservoir to the spray gun 401. In this way, the socket
421 can be adapted for non-threaded connection of a reservoir by
removing the insert 480 from the socket 421 or threaded connection
of a reservoir by positioning the insert 480 in the socket 421.
[0185] In this embodiment, the adaptor 485 screws into the insert
480 within the socket 421. In this way, the screw threaded
engagement of the adaptor 485 with the insert 480 may enhance the
frictional engagement between the insert 480 and the socket 421. As
a result, the reservoir 402 may be secured in a fluid-tight manner
that reduces the risk of inadvertent separation of the reservoir
402 from the spray gun 401 as the spray gun 401 is manoeuvred in
use.
[0186] Referring now to FIGS. 18 and 19 of the accompanying
drawings, there is shown a modification to the arrangement of FIGS.
11 and 12 for releasably securing the reservoir to the spray gun.
For convenience, like reference numerals in the series 500 are used
to indicate corresponding parts.
[0187] In this embodiment, the enlarged annular head 560 of the
connector boss 520 is provided with an internal screw thread 590
and the outer container 508 of the reservoir 502 has a
complementary external screw thread 591. In this way, the outer
container 508 can be screwed into the head 560 to secure the liner
509 in fluid-tight manner relative to the head 560.
[0188] The outer container 508 could be replaced by an open-ended
sleeve (not shown) for mounting liners of different length to vary
the volume of the reservoir 502 as described previously in
connection with FIG. 13. Alternatively, the liner 509 could be
omitted and the outer container 508 provided with an openable air
inlet in the base. In this way, liquid can be added directly to the
container 508 for mounting on the spray gun 501.
[0189] As will be appreciated, the enlarged head 560 of the
connector boss 520 forms a lid for the open end of the reservoir
502 reducing the number of parts and facilitating connection of the
reservoir 502 to the spray gun 301 in a simple manner.
[0190] In a modification, not shown, the internal screw thread 590
on the head 560 may be replaced by an external screw thread and the
outer container 508 replaced by an annular locking ring or collar
having an internal screw thread and a concentric inner sleeve or
skirt. The inner sleeve is spaced from the internal screw thread
and is received in the clearance gap between the head 560 and the
liner 509 when the collar is screwed onto the head to secure and
retain the liner 509 in the socket 521.
[0191] In another modification, not shown, the inlet connector 320,
520 with enlarged head 360, 560 may be a separate component for
securing releasably to the spray gun 301, 501 and the invention
includes provision of such a connector for mounting a reservoir to
the spray gun.
[0192] Referring now to FIGS. 20 to 52 of the accompanying
drawings, various arrangements for securing a reservoir to a spray
gun are depicted. Other details of the construction and operation
of the reservoir and spray gun are similar to the previous
embodiments and are not described or illustrated further. Where
appropriate in the following description, like reference numerals
are used in the series 600, 700, 800, 900, 1000 and 1100 to
indicate corresponding parts as well as parts similar to parts of
previous embodiments.
[0193] Referring first to FIG. 20, there is shown a non-threaded
socket 621 in the body 603 of a gravity fed spray gun. The socket
621 has a cylindrical outer bore portion 621a and a cylindrical
inner bore portion 621b connected by an internal annular shoulder
621c. The inner bore portion 621b is of smaller diameter than the
outer bore portion 621a. At the bottom of the socket 621 is a
sealing face 621d, the purpose of which will be described
later.
[0194] Spaced above the socket 612 is a radial lug 686 integral
with the gun body 603. The lug 686 extends for part of the
circumference of the socket 621 and is set back from the marginal
edge of the outer bore portion 621a.
[0195] Referring now to FIGS. 21 to 24, there is shown a plastics
moulded insert 680, for example a nylon insert 680, for mounting in
the socket 621 to convert the socket 621 to receive a threaded
connector (not shown) for attaching a paint reservoir. The threaded
connector may be an integral part of the reservoir or a separate
part to which the reservoir is releasably connected.
[0196] The insert 680 is a plastics moulding, for example a nylon
moulding, and has a tubular body provided with an external
hexagonal flange 687 at one end for engagement with a spanner or
the like tool. The insert 680 has a cylindrical upper body portion
680a depending from the flange 687 and connected to a cylindrical
lower body portion 680b of reduced diameter by an external annular
shoulder 680c.
[0197] The lower body portion 680b is sized to be an interference
fit in the inner bore portion 621b to provide a fluid tight seal
within the socket 621. The upper body portion 680a may be sized to
be an interference fit in the upper bore portion 621a but more
preferably is a close fit to facilitate insertion of the insert 680
in the socket 621 as described later.
[0198] The upper body portion 680a is provided with upper and lower
radial projections 680d, 680e of trapezium section that extend for
approximately 180 degrees around the circumference of the upper
body portion 680a. As shown, the upper projection 680d is also of
helical form whereas the lower projection 680e is entirely parallel
to the shoulder 680c. In this embodiment, the projection 680d has a
pitch of approximately 3 mm but it will be understood this is not
essential and that the pitch may be altered to suit any given
application.
[0199] The insert 680 has a through bore 688 with an upper threaded
portion 688a connected to a lower non-threaded portion 688b of
reduced diameter by an internal shoulder 688c. The shoulder 688c
provides an internal stop to limit engagement of a threaded
connector with the upper bore portion 688a to secure a paint
reservoir.
[0200] In use, the insert 680 is located in the socket 621 by first
orienting the insert so that the gap 689 that extends for
approximately 180 degrees around the circumference of the upper
body portion 680a, between the two ends of the projections 680d,
680e, is aligned with the radial lug 686 on the gun body 603. The
insert 680 can then be pushed into the socket 621 until the end of
the upper projection 680d furthest from the flange 687 is
positioned below the lug 686.
[0201] The insert 680 can then be rotated to engage the upper
projection 680d with the underside of the lug 686 as shown in FIG.
25, for example, by engaging the flange 687 with a spanner. The
helical form of the upper projection 680d provides a ramp face
co-operable with the lug 686 as the insert 680 is rotated.
[0202] As a result, the insert 680 is displaced further into the
socket 621 until the lower projection 680e engages the gun body 603
around the perimeter of the socket 621. This requires less than one
complete turn of the insert 680. The underside of the lug 686 may
be of helical form having a pitch similar to that of the projection
680d to assist axial displacement of the insert 680 by engagement
of the projection 680d with the underside of the lug 686.
[0203] At this point, the interference fit of the lower body
portion 680b in the inner bore portion 621b to provide a
fluid-tight seal between the gun body 603 and the insert 680 within
the socket 621 is assured.
[0204] The insert 680 is also locked in position and prevented from
being axially withdrawn from the socket 621 until it is rotated in
the reverse direction to re-align the lug 686 with the
circumferential gap 689 between the ends of the projections 680d,
680e.
[0205] With the insert 680 located and secured in place, the paint
reservoir can be secured to the spray gun by means of a threaded
connection to the threaded bore portion 688a of the insert 680. If
desired, the insert 680 may be held in place while the paint
reservoir is attached to or removed from the spray gun by gripping
the flange 687 with a spanner or other suitable tool. The threaded
connection may be provided as an integral part of the reservoir or
by a separate adaptor to which the reservoir can be releasably
connected.
[0206] As will be appreciated, the lower projection 680e provides a
stop to limit displacement of the insert 680 into the socket 621
and prevent the insert 680 being damaged by rotation beyond that
required to secure the insert 680 and provide an effective seal
within the socket 621. Furthermore, the insert 680 is prevented
from rotating as the connector is screwed into the bore 688a by
engagement of the projections 680d, 680e with the lug 686 and the
gun body 603 respectively.
[0207] In a modification shown in FIG. 51, an axial abutment 680h
is provided at the upper end of the helical projection 680d. The
abutment 680h provides an end stop co-operable with the lug 686 to
limit rotation of the insert 680 relative to the lug 686 and
prevent over-tightening when the insert 680 is secured in the
socket 621.
[0208] In another modification (not shown), the lug 686 may be
extended further around the circumference of the socket 621 with a
corresponding reduction in the length of the projections 680d, 680e
on the insert 680 so that the lug 686 can pass through the gap
between the ends of the projections.
[0209] In another modification (not shown), the projection 680e may
be positioned above the projection 680d so that the lug 686 is
received between the projections 680e, 680d with the projection
680e again acting as a stop to limit axial movement of the insert
680 into the socket 621 by engagement with the lug 686.
Alternatively or additionally, the helical projection 680d may be
provided with an end stop as described above to limit rotation of
the insert 680 relative to the lug 686. Alternatively, the gap
between the upper and lower surfaces of the projections 680d, 680e
may reduce sufficiently to limit rotation of the insert 680
relative to the lug 686.
[0210] Referring now to FIGS. 26 to 29, there is shown another
plastics moulded insert 780 generally similar to the insert 680
above-described.
[0211] As shown, the insert 780 has an annular flange 787 at one
end and a helical projection 780d on the upper body portion 780a
for co-operating with the radial lug 686 on the gun body 603 as
described above. The lower projection 780e is omitted and the lower
body portion 780b is of increased length and is a close fit rather
than an interference fit in the inner bore portion 621b to
facilitate insertion of the insert 780 in the socket 621.
[0212] In use, the insert 780 is inserted into the socket 621 by
aligning lug 686 with the circumferential gap 789 between the ends
of the projection 780d and rotated to locate the projection 780d
under the lug 686 on the gun body 603 as described above. The
insert 780 can then be rotated by engaging the flange 787 with a
suitable tool or when screwing the connector for the paint
reservoir (not shown) into the insert 780.
[0213] On being rotated, the insert 780 is displaced axially into
the socket 621 by engagement of the projection 780d with the
underside of the lug 686 until a sealing face 780f at the inner end
of the insert 780 contacts the sealing face 621d (FIG. 20) at the
bottom of the socket 621.
[0214] The sealing face 780f may be provided by the insert itself,
for example a lip moulded integrally with the insert 780 of the
same or softer plastics or by a seal located in the end wall of the
insert, for example a rubber O-ring (not shown). Likewise, the
sealing face 621d may be provided by the gun body 603 itself, for
example an internal abutment shoulder or by a seal located at the
bottom of the socket 621, for example a nylon sealing ring or
washer.
[0215] In a modification (FIG. 52), an axial abutment 780h is
provided at the upper end of the helical projection 780d that
provides an end stop co-operable with the lug 686 to limit rotation
of the insert 780 relative to the lug 686 and prevent
over-tightening of the insert 780. In another modification (not
shown), the lower body portion 780b may be an interference fit in
the inner bore portion 688b to provide a fluid-tight seal without
engaging the sealing face 621d at the bottom of the socket 621.
[0216] In the above-described embodiments, the helical projection
680d, 780d has a pitch of 3 mm and the co-operating surface on the
lug 686 has a similar pitch. It will be understood this is not
essential however and that any suitable pitch may be employed.
Furthermore, while the helical projections 680d, 780d and, where
provided, stop projection 680e extend for approximately 180 degrees
to leave a gap 689 of approximately 180 degrees in a
circumferential direction for passage of the lug 686, it will be
understood that this is also not essential and that the
circumferential extent of the projections 680d, 680e, 780d can be
altered provided the resulting gap 689 is of sufficient size for
the lug 686 to pass through.
[0217] Referring now to FIGS. 30 to 34, there is shown another
plastics moulded insert 880 that can be used to convert the socket
621 for engagement of a threaded connector to secure the paint
reservoir.
[0218] As shown the insert 880 has an annular flange 887 at one end
that is provided with a cut-out 887a of a size and shape to receive
the lug 686 on the gun body 603. The helical projection and stop
projection of the previous embodiments are omitted from the upper
body portion 880a and the lower body portion 880b is sized to be an
interference fit in the inner bore portion 621b to provide a
fluid-tight seal.
[0219] In use, the insert 880 is positioned with the cut-out 887a
aligned with the lug 686 on the gun body 603. The insert 880 is
then inserted axially into the socket 621 until the flange 887 is
seated on the gun body 603 around the socket 621 and the lug 686 is
received in the cut-out 887a as shown in FIG. 34. The insert 880 is
then prevented from rotating relative to the gun body 603 when the
threaded connector for securing the reservoir is screwed into the
insert 880 by engagement of the lug 686 in the cut-out 887a.
[0220] As will be appreciated, unlike the previous embodiments, the
insert 880 is not axially retained by engagement with the lug 686
and relies on the interference fit of the insert 880 in the socket
621 both to seal and retain the insert 880 in a fluid-tight manner.
The interference fit can be enhanced by forming the insert 880 so
that the upper body portion 880a will expand when the threaded
connector for securing the reservoir is screwed into place.
[0221] Referring now to FIGS. 35 to 39, there is shown another
plastics moulded insert 980 that can be used to convert the socket
621 for engagement of a threaded connector to secure the paint
reservoir.
[0222] The flange 987 is provided with a cut-out 987a and is also
formed with opposed flats 987b. The cut-out 987a is larger than the
lug 686 in a circumferential direction. As a result, the insert 980
can rotate to a limited extent when inserted in the socket 621 and
the flats 987b allow the insert 980 to be held with a tool to
prevent the insert 980 rotating when the threaded connector for
securing the reservoir is screwed into the insert 980.
[0223] Again, the insert 980 is not axially retained by engagement
with the lug 686 and relies on the interference fit of the insert
980 in the socket 621 both to seal and retain the insert 980 in a
fluid-tight manner. The interference fit can again be enhanced by
forming the insert 980 so that the upper body portion 980a will
expand when the threaded connector for securing the reservoir is
screwed into place.
[0224] Referring now to FIGS. 40 to 44, there is shown a
modification to the insert 980 in which the lower body portion 980b
is provided with a pair of axially spaced, annular sealing ribs
980d, 980e. The ribs 980d, 980e are continuous in a circumferential
direction and provide a fluid-tight seal with the inner bore
portion 621b when the insert 980 is located in the socket 621.
[0225] It will be appreciated that the number and arrangement of
the sealing ribs 980d, 980e may be altered from that shown and that
any of the inserts 680, 780, 880, 980 described herein may be
provided with one or more sealing ribs for sealing the insert in
the socket 621.
[0226] As will now be apparent, each of the inserts 680, 780, 880,
980 above-described converts the non-threaded socket 621 in the gun
body 603 to receive a threaded connector for securing a separate
paint reservoir. It will be understood, however, that the outlet
spout of the reservoir could be adapted in similar manner to each
of the inserts to permit the reservoir to be connected directly to
the socket of the gun body.
[0227] The spout and reservoir could be formed separately and
secured together, for example by welding, or they could be formed
integrally, for example by moulding. FIGS. 45 to 47 shows a moulded
plastics reservoir 1002 provided with an integral spout 1015 at one
end for connection to the socket 621 and a removable lid 1090 at
the opposite end for adding liquid to the reservoir 1002. The lid
1090 is provided with an annular seal 1091 and an air vent 1092
closed by a removable plug 1093.
[0228] As shown, the spout 1015 has a cylindrical portion 1080a
provided with a helical projection 1080d for co-operating with the
lug 686 on the gun body 603. The cylindrical portion 1080a leads to
an externally threaded portion 1080g that is a clearance fit in the
outer bore portion 621a of the socket 621 and in turn leads to a
cylindrical portion 1080b that is received in the inner bore
portion 621b of the socket 621.
[0229] The reservoir 1002 is secured to the gun body 603 in similar
manner to the insert 780 above-described by inserting the spout
1015 into the socket 621 with the lug 686 aligned with a gap 1089
between the ends of the helical projection 1080d. The reservoir
1002 is then rotated to engage the helical projection 1080d with
the underside of the lug 686 causing the spout 1015 to move into
the socket 621 until a sealing face 1080f at the inner end contacts
and forms a fluid tight seal with an opposed sealing face in the
socket 621.
[0230] In a modification (not shown), the cylindrical portion 1080b
is an interference fit within the inner bore portion 621b to
provide a fluid tight seal in similar manner to the insert 680.
Alternatively, the cylindrical portion 1080b may be provided with
one or more sealing ribs to provide a fluid tight seal with the
inner bore portion 621b similar to the insert 980.
[0231] The cylindrical portion 1080a may be provided with a second
projection similar to the insert 680 that provides a stop to limit
insertion of the spout 1015 into the socket 621. Alternatively or
additionally, an axial abutment may be provided at the upper end of
the helical projection 1080d to provide an end stop to limit
rotation of the insert relative to the lug 686.
[0232] The screw threaded portion 1080g allows the reservoir 1002
to be connected to a spray gun provided with a threaded socket
either in the gun body or in an adaptor mounted on the gun body. It
will be understood that the screw threaded portion 1080g may be
omitted.
[0233] In another arrangement, the reservoir could be provided with
a separate detachable part such as a lid and the spout and lid
could be formed separately and secured together or they could be
formed integrally. FIGS. 48 to 50 show a moulded plastics lid 1110
for a reservoir (not shown) of the type described previously with
reference to FIGS. 1 to 6.
[0234] As shown, the lid 1110 is provided with an integral spout
1115 for connection to the socket 621. The spout 1115 is similar to
the integral spout 1015 of the reservoir 1002 described above and
the construction and operation will be understood from the previous
description of the spout 1015.
[0235] The above-described embodiments illustrate the manner in
which the present invention provides a quick-fit connection to
secure releasably the reservoir to the spray gun by connector means
integral with the spray gun that avoids the use of screw
threads.
[0236] The quick-fit connection also allows the reservoir to be
releasably secured to the spray gun when containing paint by a
simple push-twist action requiring less than one complete rotation
of the reservoir that reduces the risk of spillage.
[0237] It will be appreciated that the exemplary embodiments
described herein are intended to illustrate the diverse range and
application of the invention and that features of the embodiments
may be employed separately or in combination with any other
features of the same or different embodiments.
[0238] Moreover, while the exemplary embodiments described and
illustrated are believed to represent the best means currently
known to the applicant, it will be understood that the invention is
not limited thereto and that various modifications and improvements
can be made within the spirit and scope of the invention as
generally described herein.
[0239] For example, where the outlet spout is adapted for
connection directly to the socket, a valve system may be
incorporated into the connection such that, on connecting the
spout, a shut-off device is opened to facilitate the flow of liquid
from the reservoir to the spray gun. The shut-off device may be
opened in response to insertion and/or rotation of the outlet in
the socket and closed by a reverse operation when disconnecting the
reservoir.
[0240] Other arrangements for releasably securing the reservoir to
the spray gun will be apparent to those skilled in the art. For
example, the socket may be recessed in the body of the gun and
adapted to receive the connector tube of the reservoir. The
reservoir and spray gun may be provided with any suitable
inter-engageable formations for releasably securing the reservoir
to the spray gun without employing multiple screw threads on the
reservoir and spray gun.
[0241] It will also be understood, that each of the inserts could
be adapted to convert the socket to mount the reservoir using any
other connection system to secure the reservoir to the insert. For
example, the insert and reservoir could be provided with
interengageable bayonet formations as shown in FIG. 9.
Alternatively, one of the insert and reservoir could be provided
with a flange and the other with at least one hook member
engageable with the flange as shown in FIGS. 5 and 6.
Alternatively, one of the insert and reservoir could be provided
with a flange and the other with at least one spring leg arranged
to engage the flange and permit rotation of the reservoir relative
to the socket in a fluid tight manner as described in our
co-pending UK patent application No. 0307902.7 filed 5 Apr.
2003.
[0242] The reservoir may be of any construction for containing
paint to be delivered to the spray gun. For example, the reservoir
may contain the paint in a collapsible container that is thrown
away on completion of spraying as described. Alternatively, the
reservoir may contain the paint in a re-usable paint pot that is
cleaned on completion of spraying.
[0243] The reservoir may be constructed to permit paint to be added
to the reservoir while attached to the spray gun. In this way, the
reservoir may be re-filled without detaching the reservoir from the
spray gun to allow spraying of areas requiring a larger volume of
paint than the reservoir can hold. As a result, the reservoir can
be of a compact size and shape that facilitates handling the spray
gun. In particular, the balance, stability and manoeuvrability of
the spray gun may be enhanced by employing a re-fillable reservoir
of low volume.
[0244] The reservoir may be pre-filled with the paint to be
sprayed. Alternatively, the reservoir may be supplied empty and
filled by the end user. Pre-filling may be advantageous for
spraying paints of standard colours that do not require special
matching of the colour, for example primers, base coats etc.
[0245] The invention provides spray guns and reservoirs with
integral co-operating formations that are mateable without screw
threads. However, we may provide an adaptor plug for converting an
existing paint pot having a screw threaded connector boss for use
with the spray gun. Such plug may be screwed onto the connector
boss of the paint pot and provided with formations for engagement
with the non-threaded formations on the body of the spray gun. In
this way, existing paint pots with a threaded connector boss can be
used with the spray gun of the present invention.
[0246] The spray gun may be of the gravity feed type described
herein. Alternatively, the spray gun may be of the suction feed
type or pressure feed type. The pressure feed type may employ a
bleed line from the compressed air supply to the gun to assist
delivery of the paint from the reservoir to the spray gun. The
invention may also apply to other types and constructions of spray
guns for spraying liquids as defined herein.
[0247] Other modifications and improvements will be apparent to
those skilled in the art and are deemed within the scope of the
invention.
* * * * *