U.S. patent application number 12/199095 was filed with the patent office on 2009-03-05 for upright vacuum cleaner.
This patent application is currently assigned to Miele & Cie. KG. Invention is credited to Klemens Andrup, Udo Mersmann.
Application Number | 20090056055 12/199095 |
Document ID | / |
Family ID | 40029351 |
Filed Date | 2009-03-05 |
United States Patent
Application |
20090056055 |
Kind Code |
A1 |
Andrup; Klemens ; et
al. |
March 5, 2009 |
UPRIGHT VACUUM CLEANER
Abstract
An upright vacuum cleaner for cleaning a surface includes a base
unit, a carriage configured to provide movement of the base unit on
the surface and an upper body including a dust collection container
therein. A substantially U-shaped elongated receiving structure is
recessed into at least one side surface of the upper body and at
least a portion of an upper surface of the upper body. The vacuum
cleaner includes an air passageway with an interface and a section
formed by a hose or an assembly of the hose and a wand, the section
being connected downstream of the interface. The section is
externally disposed on the upper body with at least the hose being
receivable on the receiving structure. The section is
disconnectable in a region of the interface so as to enable a
vacuuming mode of operation that is independent of the base
unit.
Inventors: |
Andrup; Klemens; (Verl,
DE) ; Mersmann; Udo; (Guetersloh, DE) |
Correspondence
Address: |
DARBY & DARBY P.C.
P.O. BOX 770, Church Street Station
New York
NY
10008-0770
US
|
Assignee: |
Miele & Cie. KG
Guetersloh
DE
|
Family ID: |
40029351 |
Appl. No.: |
12/199095 |
Filed: |
August 27, 2008 |
Current U.S.
Class: |
15/323 |
Current CPC
Class: |
A47L 9/0036 20130101;
A47L 5/30 20130101; A47L 5/32 20130101; A47L 9/0018 20130101; A47L
9/0411 20130101 |
Class at
Publication: |
15/323 |
International
Class: |
A47L 9/28 20060101
A47L009/28 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 30, 2007 |
DE |
10 2007 040 956.9 |
Claims
1: An upright vacuum cleaner for cleaning a surface, the upright
vacuum cleaner comprising: a base unit; a carriage configured to
provide movement of the base unit on the surface; an upper body
having a dust collection container disposed therein, the upper body
being supported so as to be at least tiltable relative to the base
unit and lockable in a parked position in which the vacuum cleaner
has a substantially upright configuration when standing on the
surface; a motor-fan unit configured to provide a partial vacuum at
the surface; a substantially U-shaped elongated receiving structure
recessed into at least one side surface of the upper body and at
least a portion of an upper surface of the upper body; and an air
passageway including an interface and a section formed by a hose or
an assembly of the hose and a wand, the section being connected
downstream of the interface, the section being disposed externally
on the upper body and at least the hose being receivable by the
receiving structure, the section being disconnectable in a region
of the interface so as to enable a vacuuming mode of operation that
is independent of the base unit.
2: The upright vacuum cleaner as recited in claim 1 wherein, in a
received position of the hose, the U-shaped receiving structure
extends along an entire length of the hose except at a region of
transition of the hose to the upper body.
3: The upright vacuum cleaner as recited in claim 2 wherein the
receiving structure has a cross-section of a quadrant of a circle
in the region of transition.
4: The upright vacuum cleaner as recited in claim 3 further
comprising an elbow swively disposed on the upper body in the
region of transition.
5: The upright vacuum cleaner as recited in claim 4 further
comprising an anti-kink sleeve disposed in the region of transition
and configured to receive a section of the hose.
6: The upright vacuum cleaner as recited in claim 1 wherein the at
least one side surface includes a first and a second side surface
and wherein the air passageway section includes the assembly of the
hose and the wand, at least a portion of the hose being receivable
in the first side surface and the wand being receivable in the
second side surface.
7: The upright vacuum cleaner as recited in claim 2 wherein the at
least one side surface includes a first and a second side surface
and wherein the air passageway section includes the assembly of the
hose and the wand, at least a portion of the hose being receivable
in the first side surface and the wand being receivable in the
second side surface.
8: The upright vacuum cleaner as recited in claim 3 wherein the at
least one side surface includes a first and a second side surface
and wherein the air passageway section includes the assembly of the
hose and the wand, at least a portion of the hose being receivable
in the first side surface and the wand being receivable in the
second side surface.
9: The upright vacuum cleaner as recited in claim 4 wherein the at
least one side surface includes a first and a second side surface
and wherein the air passageway section includes the assembly of the
hose and the wand, at least a portion of the hose being receivable
in the first side surface and the wand being receivable in the
second side surface.
10: The upright vacuum cleaner as recited in claim 5 wherein the at
least one side surface includes a first and a second side surface
and wherein the air passageway section includes the assembly of the
hose and the wand, at least a portion of the hose being receivable
in the first side surface and the wand being receivable in the
second side surface.
11: The upright vacuum cleaner as recited in claim 6 wherein the
wand includes a telescoping wand.
12: The upright vacuum cleaner as recited in claim 6 wherein the
air passageway section includes a wand handle disposed between the
wand and the hose.
13: The upright vacuum cleaner as recited in claim 11 wherein the
air passageway section includes a wand handle disposed between the
wand and the hose.
14: The upright vacuum cleaner as recited in claim 1 wherein the
hose includes a flexible hose that is extensible in length.
15: The upright vacuum cleaner as recited in claim 2 wherein the
hose includes a flexible hose that is extensible in length.
16: The upright vacuum cleaner as recited in claim 3 wherein the
hose includes a flexible hose that is extensible in length.
17: The upright vacuum cleaner as recited in claim 4 wherein the
hose includes a flexible hose that is extensible in length.
18: The upright vacuum cleaner as recited in claim 5 wherein the
hose includes a flexible hose that is extensible in length.
19: The upright vacuum cleaner as recited in claim 1 wherein an end
of the air passageway section adjacent to the interface is
configured to receive vacuum attachments.
20: The upright vacuum cleaner as recited in claim 19 wherein a
rear wall of the upper body is configured to secure the vacuum
attachments thereto.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Priority is claimed to German patent application DE 10 2007
040 956.9, filed Aug. 30, 2007, which is hereby incorporated by
reference herein.
FIELD
[0002] The present invention relates to a vacuum cleaner of the
upright type, including an upper body containing a dust collection
container, a base unit, and a carriage permitting said base unit to
move on the surface to be cleaned.
BACKGROUND
[0003] The following is a description of three types of vacuum
cleaners which differ in design and operation. All of them have as
common features a motor-driven fan, a dust collection chamber, and
one or more floor treatment devices which are each adapted for a
particular purpose.
[0004] The canister vacuum cleaner has a housing which can be moved
on the floor to be cleaned on wheels and/or runners. The housing
contains the motor-fan unit and the dust collection container. The
floor treatment device, here referred to as floor nozzle, is
connected to the dust collection chamber via a suction hose, and
possibly a suction wand connected therebetween. During vacuuming,
the housing is moved to the desired position by pulling on the
suction wand.
[0005] In a stick vacuum cleaner, the motor-fan unit and the dust
collection container are also disposed in a housing. A suction wand
extends from one end of the housing, connecting the floor nozzle to
the dust collection container, and a handle used to maneuver the
housing to the desired position extends from the other end.
[0006] Uprights do not have as strictly divided a configuration as
the two aforementioned types. One feature of an upright is a
movable base unit which carries an upper body containing a large
dust collection container. The two parts are tiltable relative to
each other and can usually be locked in a parked position in which
the upper body is nearly upright when the base unit is located on a
horizontal floor in a position of use. In this position, the
upright stands unsupported. During vacuuming, the above-described
locked engagement is released, and the upper body is tilted through
a certain angle to an operating position. The tilt angle depends on
the height of the user and on the particular purpose of use. A
handle is provided on the upper body for maneuvering the entire
appliance. In order to give the user additional options for
vacuuming besides vacuum cleaning with the base unit, such as
above-the-floor-vacuuming, the air passageway has an interface and,
downstream thereof, a section which is formed by a hose or
hose/wand assembly. In most designs, a wand member is held in an
insertion receptacle. After removing the wand member from the
insertion receptacle, different types of vacuum attachments may be
attached to the suction end thereof. The assembly so formed can be
used in the same manner as with a conventional canister vacuum
cleaner. The aforementioned assembly uses a relatively long hose to
provide adequate reach for the user (see, for example, WO
2007/008770 A1). Such hoses are then secured in clamps or hooks on
the handle. In the process, loops are formed above the upper body.
Such loops may get caught on various objects as the user moves
around.
SUMMARY
[0007] An aspect of the present invention is to provide an upright
vacuum cleaner in which the hose is held in a reliable and
ergonomically favorable manner.
[0008] In an embodiment, the present invention provides an upright
vacuum cleaner for cleaning a surface. The upright vacuum cleaner
includes a base unit, a carriage configured to provide movement of
the base unit on the surface and an upper body including a dust
collection container therein. The upper body is supported so as to
be at least tiltable relative to the base unit and lockable in a
parked position in which the vacuum cleaner has a substantially
upright configuration when standing on the surface. The vacuum
cleaner includes a motor-fan unit configured to provide a partial
vacuum at the surface. A substantially U-shaped elongated receiving
structure is recessed into at least one side surface of the upper
body and at least a portion of an upper surface of the upper body.
The vacuum cleaner includes an air passageway with an interface and
a section formed by a hose or an assembly of the hose and a wand,
the section being connected downstream of the interface.
[0009] The section is externally disposed on the upper body with at
least the hose being receivable on the receiving structure. The
section is disconnectable in a region of the interface so as to
enable a vacuuming mode of operation that is independent of the
base unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] An exemplary embodiment of the present invention will be
described below and is schematically shown in the drawings, in
which:
[0011] FIGS. 1 through 6 show various overall views of the vacuum
cleaner of the present invention;
[0012] FIG. 7 is an exploded view showing the base unit of the
vacuum cleaner;
[0013] FIG. 8 is an exploded view illustrating the upper body of
the vacuum cleaner;
[0014] FIG. 9 is a rear view showing the upper body and portions of
the air passageway in an exploded view;
[0015] FIG. 10 is a cross-section through the upper body in the
transition region from the hose to the upper body;
[0016] FIGS. 11a and 11b show the swivel elbow in different
views;
[0017] FIG. 12 shows the relationship of forces and moments arising
when a pull is exerted on the hose in a direction opposite to the
direction of travel; and
[0018] FIG. 13 shows the relationship of forces and moments arising
when a pull is exerted on the hose in a direction angular to the
direction of travel
DETAILED DESCRIPTION
[0019] The present invention relates to a vacuum cleaner of the
upright type, including an upper body containing a dust collection
container, a base unit, a carriage permitting said base unit to
move on the surface to be cleaned; the upper body being supported
such that it is at least tiltable relative to the base unit and
capable of being locked in a parked position in which the vacuum
cleaner assumes a substantially upright position when standing on
the surface to be cleaned; the vacuum cleaner further including a
motor-fan unit for creating a partial vacuum to act on the surface
to be cleaned, and an air passageway extending from the base unit
to the dust collection container, said air passageway having an
interface and including a section which is formed by a hose or
hose/wand assembly and is located downstream of said interface,
said section being arranged externally on the upper body in such a
manner that it is securable thereto and that, when disconnected in
the region of the interface, it enables a vacuuming mode of
operation which is independent of the base unit.
[0020] In an embodiment of the present invention the hose can be
held in an elongated receiving structure which is substantially
U-shaped and is recessed into at least one side surface and at
least a portion of the upper surface. Thus, on the one hand, loops
projecting beyond the upper body are avoided and, on the other
hand, this assists in the placing back of the hose, because when
the vacuum cleaner is in the parked position, the hose
automatically moves toward the receiving structure with the
assistance of gravity, and remains therein.
[0021] In an embodiment, the U-shaped receiving structure extends
along nearly the entire length of the hose in the retained
position, with only a transition region from the hose to the upper
body being left free. Thus, when vacuuming with the base unit while
the upper body is tilted rearward, the hose is prevented from
hanging down, and thus, from forming loops.
[0022] In the transition region, the receiving structure may have a
cross-section of a quadrant of a circle. Thus, the transition
region may include an elbow which is swivel-mounted to the upper
body, which increases the vertical stability of the upright when
the hose is pulled far in a rearward direction. In order to prevent
the hose from being damaged at the frequently stressed point
immediately downstream of the swivel elbow, it is advantageous if
the transition region is formed by the elbow and a hose section
which is surrounded by an anti-kink sleeve.
[0023] In another embodiment, the section downstream of the
interface includes a wand member which can also be held in a
U-shaped receiving structure, said receiving structure being
recessed into another side surface of the upper body. This wand
member, which may be in the form of a telescoping wand and, in
addition, is supplemented by a wand handle, allows the upright to
be used without stooping in the manner of a conventional canister
vacuum cleaner.
[0024] The hose may be in the form of a flexible hose which is
extensible in length. Thus, the reach is increased.
[0025] In one embodiment vacuum attachments can be attached to the
hose or wand end adjacent to the interface. Such vacuum attachments
may be securable to the rear wall of the upper body.
[0026] The upright vacuum cleaner shown in different views in FIGS.
1 through 6 (hereinafter abbreviated as upright 1) includes a base
unit 2, an upper body 3, and a joint disposed therebetween, which
will be described in greater detail further on in this
specification.
[0027] Upright 1 can be brought from an upright position (see FIGS.
1 through 3), in which it can be locked and stand unsupported, to a
tilted position (FIGS. 4 and 5), or even to a fully flat position
(FIG. 6), after the locked engagement has been released (see FIG.
7). To this end, base unit 2 and upper body 3 are connected in such
a manner that they can be tilted relative to each other about an
axis X extending horizontally in a position of use (see FIG. 5).
This pivoting movement is made possible by a joint which is
hereinafter referred to as "tilting joint". In the tilted position,
the upright can be rotated about an axis Y, as is also shown in
FIG. 5. The user can maneuver base unit 2 through curves by
rotating upper body 3 about the aforesaid axis using handle 4 while
simultaneously pulling or pushing the upright. The corresponding
joint is hereinafter referred to as "swivel joint".
[0028] Base unit 2, shown in the exploded view of FIG. 7, has a
housing including a housing insert 5, a lower rear housing part 6,
a lower front housing part 7, a bumper strip 8, and a cover part 9.
Housing insert 5 functions as a support for a number of electrical
and mechanical components. The aforementioned housing parts are
also attached thereto. The housing insert, lower rear housing part
6, and a motor chamber seal 10 placed therebetween, together form a
chamber for receiving a motor-fan unit 11 for creating the partial
vacuum required for vacuuming. A sealing ring 13 is provided around
fan inlet 12 on the suction side, said sealing ring also bearing
against the two aforementioned housing parts 5 and 6. Rubber
buffers 14 are inserted on the opposite side. For deep cleaning of
carpets, a brush roller 17 extends into suction mouth 15, which is
an opening in lower front housing part 7 and bottom plate 16, which
is attached thereto, said brush roller being resiliently mounted on
two lateral pivoting arms 18 and 19 and being driven by a brush
motor 20 via a belt 21. A two-part belt cover is provided by parts
22 and 23. Brush motor 20 is also attached to housing insert 5, and
pivoting arms 18 and 19 are pivotably secured thereto. The carriage
of the upright is formed by front casters 24 and 25 and rear wheels
26 and 27 and is supported by the two lower housing parts 6 and 7.
Rear wheels 26 and 27 are connected by an axle 28 for purposes of
stability, and are adjustable in position by means of a wheel
mechanism 29 and 30, respectively. A circuit board 31 carrying LEDs
32 is secured to housing insert 5 to illuminate the travel path and
is covered at the front by a transparent plate 33. Transparent
plate 33 is held in a cut-out 34 in bumper strip 8.
[0029] The air generated by the motor-fan unit 11 is discharged
into the environment through an opening 35 in housing insert 5 and
a corresponding opening 36 in cover part 9. A filter frame 37 is
inserted into opening 36 to hold an exhaust filter for removing
ultrafine particles from the exhaust air. Filter frame 37 is
covered by a grating holder 38 and a grating 39 within cover part
9, from where it can be replaced.
[0030] Both the tilting joint and the swivel joint between base
unit 2 and upper body 3, which will be described in greater detail
hereinafter, are provided by a rigid, yoke-shaped duct member. This
member also contains portions of the air passageway from suction
mouth 15 to upper body 3, and the air passageway from upper body 3
to the exhaust port (openings 35 and 36). This member is
hereinafter referred to as yoke 40. It is formed by two plastic
parts, an upper shell 41 and a lower shell 42, which are welded
together. In order to create the tilting joint, the two ends 43
(right) and 44 (left) of yoke 40 are pivotably mounted in openings
45 and 46 provided for this purpose, and are surrounded by metal
bearing sleeves 47 and 48, respectively, in order to avoid wear.
Yoke end 44, which is on the left side as viewed in the direction
of travel, is hollow and is coupled to fan inlet 12 via a seal 49.
A trunnion 50 is integrally formed with yoke end 43, which is on
the right side as viewed in the direction of travel. Moreover, the
right yoke end has an opening 51 which is connected by a flexible
tube 52 to suction mouth 15. In order to prevent the interior of
base unit 2 from becoming visible when tilting the upper body 3,
the connecting portion between the two yoke ends 43 and 44
(hereinafter referred to as bridge portion 53) is enclosed by a
front cover 54 and a rear cover 55, which are provided on base unit
2 and are capable of following the swivel motion of yoke 40. The
gap between the front and rear covers and housing insert 5 is
bridged by covering members 56 and 57. The first 58 of two cable
ducts 58 and 59 is attached to left yoke end 44. Furthermore, yoke
ends 43 and 44 carry toothed segments 60 and 61, which cooperate
with wheel mechanisms 29 and 30. A covering cap 62 for a connecting
cable is secured to bridge portion 53. To enable the upright to be
locked in the upright position (FIGS. 1 through 3), a foot pedal 63
is mounted on housing insert 5 which, in this position, engages
with left yoke end 44, thereby preventing yoke 40 from swiveling.
The locked position can be released by depressing pedal 63.
Moreover, in the locked position, swivel motion is prevented by two
spring-mounted pins 64 and 65. In the region of bridge portion 53,
the air passages provided by yoke ends 43 and 44 are combined into
a first section 66 of a coaxial conduit.
[0031] FIG. 8 shows upper body 3, also in an exploded view. The
load-bearing part of upper body 3 is a rear wall 67. The aforesaid
rear wall forms the rear portion of a dust chamber 68, which in
turn receives a dust collection container in the form of a filter
bag. A seal 69 surrounds the edge of dust chamber 68, and a
covering strip 70 for cables is attached at the side. A hinge
bearing 71 is secured to rear wall 67 in the lower portion thereof.
Dust chamber 68 is closed at the front by an upper housing part 72
which is pivoted to hinge bearing 71 by hinges 73 and torsion
springs 74. Upper housing part 72 carries a locking device 75, a
dust bag holder 76, and a filter replacement indicator 77 and, in
addition, serves to cover hinge bearing 71. In the upper portion,
rear wall 67 carries the electronics 78 of the upright, which are
completely arranged on a holder 79 and can be installed as a
pre-tested subassembly. A lever 81 for turning off brush motor 20
is mounted to the holder via a torsion spring 80. In addition, said
holder is used to hold handle tube 82 and appliance handle 4.
Electronics 78 are covered by a cap 84, which also serves for
attachment of various controls and indicators and accessories
thereof (transparent cover 85, rotary knob 86).
[0032] An air path system allows dirt-laden air to be optionally
sucked in either through the suction mouth in the base unit or
through a telescoping wand to which may be attached vacuum
attachments such as a crevice tool, a dusting brush, an upholstery
tool, etc. To this end, the suction air is directed from suction
mouth 15 through flexible tube 52 and right yoke end 43, and
further through the inner tube of first section 66 of the coaxial
conduit in bridge portion 53 into the inner tube of a second
section 87 of the coaxial conduit. This section 87 is continued in
rear wall 67, where it is divided into two separate conduits. The
air path continues through a suction duct member 88 into an elbow
89. A telescoping wand 90 is loosely, and therefore removably,
inserted into elbow 89. The aforesaid telescoping wand merges into
a wand handle 91 and further into a flexible suction hose 92.
Suction hose 92 is held in a receiving structure 93 provided for
this purpose, as can be seen also in FIG. 3. The air passes through
a swivel elbow 94 into a duct 83 (see FIG. 10) which extends along
the entire length of rear wall 67. Duct 83 is defined by rear wall
67 itself and an air duct member 95 placed thereon. A downstream,
elbow-shaped duct member 96, which is formed by rear wall 67 and a
portion of electronics holder 79, directs the dirt-laden suction
air into the region of dust bag holder 76, and there into a dust
bag. Once the suction air has passed through the dust bag in the
dust chamber and been cleaned of dust therein, it passes through a
motor protection filter (the figure shows only the frame 97 for
holding the filter) and into the outer annulus of second section 87
of the coaxial conduit, and from there through first section 66 and
left yoke end 44 to motor-fan unit 11.
[0033] The lower portion of FIG. 8 further shows the components
used for attaching and rotatably supporting upper body 3 on yoke
40. First section 66 of the coaxial conduit is surrounded by a
metal ring 98 which is enclosed by injection-molded material and
projects beyond the outside diameter of said section 66, and which
is held around its circumference in two bearing shells 99 and 100.
Bearing shells 99 and 100 are connected to upper body 3.
Accordingly, metal ring 98 and bearing shells 99 and 100 together
form the swivel joint of upright 1. When joining upper body 3 and
yoke 40, the two sections 66 and 87 of the coaxial conduit are
joined together with a seal 101 interposed therebetween.
[0034] The air path portion that enables vacuuming independently of
base unit 2 is shown in an exploded view in FIG. 9. Elbow 89
provides the interface at which this portion can be separated.
Telescoping wand 90 is inserted in elbow 89 and can be removed
therefrom. Telescoping wand 90 is, in turn, detachably secured to
wand handle 91. Various vacuum attachments, including a dusting
brush 102, an upholstery tool 103 and a crevice tool 104, are
secured on the outside of rear wall 67 of the upper body, and may
optionally be attached to either telescoping wand 90 or wand handle
91. Wand handle 91 is connected to flexible suction hose 92, the
transition region from handle 91 to hose 92 being surrounded by an
upper anti-kink sleeve 105. Flexible hose 92 is then connected to
swivel elbow 94, this second transition region from hose 92 to
swivel elbow 94 being surrounded by a lower anti-kink sleeve
106.
[0035] It can be seen from FIGS. 3 and 9 that receiving structure
93, which holds telescoping wand 90, wand handle 91 and hose 92, is
U-shaped and extends along nearly the entire length of the two side
surfaces 107 and 108 and upper surface 109 of upper body 3. At side
surface 108, which is on the left side as viewed in the direction
of travel and shown to the left in FIG. 9, only the second
transition region, which is formed by swivel elbow 94 and lower
anti-kink sleeve 106, is left free. It can be seen both in FIGS. 3
and 9 and in the cross-sectional view of FIG. 10 that receiving
structure 93 is recessed into side surfaces 107 and 108 and into
upper surface 109. The cross-sectional view of FIG. 10 further
illustrates that in the second transition region on left side 108,
receiving structure 93 has a cross-section of only a quadrant of a
circle. Since receiving structure 93 is arranged in side surfaces
107 and 108 and in upper surface 109 of upright 1, the open side of
the receiving structure 93 faces upward and to the left and right
sides of upright 1 when it is in the parked position (FIGS. 1
through 3). After completion of a vacuuming operation in a mode
that is independent of base unit 2, the user can simply insert
telescoping wand 90 into elbow 89. An additional positioning aid is
provided by a hook 110 on wand handle 91, which is inserted into an
aperture 111 in receiving structure 93. Telescoping wand 90 and
wand handle 91 are then received by receiving structure 93 in right
side wall 107. In this process, flexible hose 92 lays itself into
the portion of receiving structure 93 that faces toward upper
surface 109. The remainder of the hose 92 can then be stored in
receiving structure 93 at left side wall 108 with a slight pressure
from the side. The upper anti-kink sleeve 105 behind wand handle 91
is made from a relatively soft plastic material, such as TPE or
PVC, having a hardness between 60 and 70 Shore A, and can therefore
be easily pressed into receiving structure 93.
[0036] Swivel elbow 94 is rotatably mounted on the inlet of duct
83, which is provided by rear wall 67 and the air duct member 95
placed thereon. Projection 941, which projects into the duct, is
surrounded by a seal 112 and a torsion spring 113, one end 114 of
which is secured to swivel elbow 94 itself. The other end 115 rests
in a guide in duct 83. Thus, rotation of swivel elbow 94 from the
position shown in FIG. 1a to the position shown in FIG. 11b is
against the force of torsion spring 113. Rotation can be through
110.degree. degrees. In this position, the rib 116 formed on elbow
94 lockingly engages the latching nose 117 of rear wall 67, and
elbow 94 is retained in this position until hose 92 is pulled
upwardly, releasing the locked engagement. The force of torsion
spring 113 is selected such that it allows hose 92 and swivel elbow
94 to swivel relatively freely between the 12 o'clock position
(FIG. 11a) and the 3 o'clock position and yet assists in the return
movement to the 12 o'clock position. To this end, lower anti-kink
sleeve 106 may be made from a relatively hard, inflexible material,
such as polypropylene. Accordingly, the unstable flexible hose 92
can be supported and guided. For this purpose, anti-kink sleeve 106
may be at least 140 mm in length.
[0037] FIG. 12 shows the relationship of forces arising in a
situation where the swivel elbow has been rotated through
110.degree. and locked in position and the user pulls upright 1
behind him/her by hose 92. In this position, swivel elbow 94 and
lower anti-kink sleeve 106 act as a lever arm of length X. When
pulling horizontally in direction F1, the pulling force acts at a
point far below the center of gravity S in very close proximity to
the tip-over point defined by the rear wheels (line of force c).
Because of this, the overturning moment produced by this force F1
is smaller than in a situation where a pull is exerted on a
non-swivel elbow in the 12 o'clock position (line of force a) or on
a swivel elbow in the 3 o'clock position (line of force b). When
pulling in direction F2, lever arm X produces a moment M2 which
even counteracts the overturning moment M1. Accordingly, elbow 94
and its locking engagement means 116 and 117 contribute to the
vertical stability of upright 1.
[0038] When, as shown in FIG. 13, the user pulls on hose 92 in a
direction angular to the direction of travel while swivel elbow 94
is locked in position, then a moment M3 produced by lever arm X
acts in a horizontal plane and turns the upright about its vertical
axis a until the carriage is oriented in the pulling direction and
the horizontal moment M3 disappears. This prevents lateral
overturning.
[0039] The present invention has been described herein based on one
or more exemplary embodiments, but is not limited thereto.
Reference should be had to the appended claims.
* * * * *