U.S. patent number 3,843,183 [Application Number 05/281,139] was granted by the patent office on 1974-10-22 for vacuum pick-up instrument.
Invention is credited to Clifford L. Hutson.
United States Patent |
3,843,183 |
Hutson |
October 22, 1974 |
VACUUM PICK-UP INSTRUMENT
Abstract
An instrument generally similar to a pencil in size and
configuration has a vacuum-actuated nozzle to pick up small
objects. A slide valve movable by the index finger has one position
to connect the nozzle to a vacuum source, a second position to cut
off the nozzle from the source to maintain a vacuum in the nozzle,
and a third position to vent the nozzle to the atmosphere for the
purpose of releasing the small object. A small wheel on the body of
the instrument is manipulated by a finger to rotate the nozzle to
control the orientation of a small object on the nozzle tip.
Inventors: |
Hutson; Clifford L. (Glendale,
CA) |
Family
ID: |
23076106 |
Appl.
No.: |
05/281,139 |
Filed: |
August 16, 1972 |
Current U.S.
Class: |
294/186; D8/71;
137/625.25; 251/344; 968/672 |
Current CPC
Class: |
B25B
11/007 (20130101); G04D 1/028 (20130101); Y10T
137/8667 (20150401) |
Current International
Class: |
B25B
11/00 (20060101); G04D 1/00 (20060101); G04D
1/02 (20060101); B66c 001/02 () |
Field of
Search: |
;294/64R,64A
;74/417,416,553 ;D74/17B ;116/124R,124.1R ;269/21 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
IBM Technical Disclosure Bulletin, V. J. Delgado & L. S.
Sheiner; "Vacuum Pick-Up Device," vol. 9, no. 7, December 1966,
page 950..
|
Primary Examiner: Blunk; Evon C.
Assistant Examiner: Rowland; James L.
Attorney, Agent or Firm: Weilein; Paul A.
Claims
I claim:
1. In a vacuum-actuated pick-up instrument to be held in the hand
of an operator for handling small objects, which instrument has an
elongated body with a pick-up nozzle extending forwardly from the
forward end of the body and a valve on said body for controlling
vacuum at said nozzle,
the improvement comprising:
at least the tip portion of said nozzle being continuously
rotatable;
a manually rotatable control member on said body adjacent said
valve;
and means drivingly connecting said manually operable control
member to said tip portion of the nozzle for rotation thereof by
remote control from the instrument body.
2. An improvement as set forth in claim 1 in which said body has a
forwardly extending tubular air passage in communication with the
tip portion of the nozzle to evacuate the tip portion of the nozzle
and in which said operatively connecting means includes a forwardly
extending tubular shaft rotatably surrounding said air passage to
transmit movement from said control member to said tip portion of
the nozzle.
3. An improvement as set forth in claim 2 in which said control
member is a manually operable control member oriented with its
plane of rotation longitudinally of the instrument and in which
said operatively connecting means includes gearing operatively
connecting said wheel to the tubular shaft.
4. An improvement as set forth in claim 3 in which said gearing
includes a drive gear on the rear end of the tubular shaft.
5. An improvement as set forth in claim 4 in which the gearing
includes a circular series of teeth fixedly connected to the hand
wheel to drive the driven gear.
6. An improvement as set forth in claim 5 which includes gear teeth
on the periphery of the hand wheel for contact by the index finger
of the operator, the gear teeth engaging said driven gear at the
inner end of the tubular shaft.
7. An improvement as set forth in claim 5 which includes an idler
gear in mesh with the driven gear and in engagement with said
series of teeth.
8. An improvement as set forth in claim 5 in which the rim of the
hand wheel is smooth.
9. An improvement as set forth in claim 5 in which said gear teeth
are formed by recesses on one face of the hand wheel.
10. An improvement as set forth in claim 1, in which the means
operatively connecting the control means to the tip portion
includes a coil spring rotatably embracing said nozzle.
11. An improvement as set forth in claim 10 in which the nozzle has
a downward bend and said coil spring embraces the bend of the
nozzle.
12. An improvement as set forth in claim 1 wherein said valve
includes a slide on the upper side of the elongated body for
manipulation by the index finger of the operator to control the
creation of a vacuum in the pick-up nozzle.
13. An improvement as set forth in claim 12 in which said hand
wheel is also on the upper side of the elongated body for
manipulation by the index finger of the operator.
14. An improvement as set forth in claim 12 in which hand said
wheel is below the top surface of the elongated body with the
periphery of the wheel protruding from the two opposite sides of
the body for manipulation by the third finger of either hand of the
operator.
15. An improvement as set forth in claim 1 in which:
the cross sectional configuration of the body of the instrument is
generally triangular with one side of the triangle uppermost to
provide a top longitudinal surface extending across the width of
the instrument for contact by the index finger of the operator and
to provide two downwardly convergent longitudinal surfaces for
contact by the thumb and second finger respectively to resist
rotation of the instrument about its longitudinal axis and to cause
the pressure against any one of the three longitudinal surfaces to
be opposed and balanced by pressure against the other two
longitudinal surfaces to promote stability of the instrument;
and in which the periphery of the hand wheel is exposed at both of
the downwardly convergent longitudinal surfaces of said body.
16. In a pick-up instrument having a body to be held in the hand of
an operator, wherein the body is provided with a pick-up nozzle to
hold a small body by vacuum action, and wherein the body is
provided with a movable vacuum control member to control the vacuum
in the pick-up nozzle and the body is provided with a manually
rotatable control member for rotary control of the pick-up nozzle,
the improvement comprising:
said body having an elongated core with said control members
mounted thereon and said vacuum control member being slidable on
the outer surface thereof;
said body having a sleeve enclosing at least the portion of said
core where said control members are located,
said sleeve being connected to the core and being of substantially
larger cross sectional area than the core to provide clearance
space between the core and the sleeve,
said sleeve being apertured to provide access to said control
members;
and said vacuum control member having portions movable in said
clearance space and being retained against said body by said
sleeve.
17. An improvement as set forth in claim 16 in which the cross
sectional configuration of said sleeve is generally triangular with
one side of the triangle uppermost to provide a top longitudinal
surface extending across the width of the instrument for contact by
the index finger of the operator and to provide two downwardly
convergent longitudinal surfaces for contact by the thumb and
second finger respectively to resist rotation of the instrument
about its longitudinal axis and to cause the pressure against any
one of the three longitudinal surfaces to be opposed and balanced
by pressure against the other two longitudinal surfaces to promote
stability of the instrument.
Description
BACKGROUND OF THE INVENTION
It is exceedingly difficult to use the fingers to pick up, handle,
and precisely position small objects that are of only a small
fraction of an inch in cross dimension. In the first place, an
operator's fingers are awkward instruments for picking up such
small objects. In the second place, when a small object is picked
up by the thumb and index finger, the thumb and index finger
overshadow the object to cut off adequate observation of the
object. In the third place, the thumb and forefinger are much too
awkward for rotating such a small object precisely to a
predetermined orientation and especially so if the object is flat
and thin. These difficulties are compounded if it is necessary to
handle the small object under a microscope where small movements
are magnified and where the fingers interfere with observation of
the small object.
Accordingly, there has been a growing need for a suitable
instrument to pick up and maneuver exceedingly small parts, the
need being felt in such fields as electronics, dentistry, jewelry,
cameras and watches. There is an especially pressing need for such
a tool in the fabrication of miniaturized electronic devices where
complex photochemical processes are employed to provide a
multiplicity of integrated circuits on silicon chips or wafers
which may be of a size ranging downward from one-tenth inch square
to microscopic sizes. Such silicon chips are vulnerable to damage
by contamination, dust particles, and scratches and are much too
delicate to be handled by mechanical forceps. With even the best
pick-up devices heretofore available, a large percentage of silicon
wafers must be rejected.
One prior art expedient for handling an exceedingly small silicon
wafer is to use a toothpick that is dipped in alcohol to cause the
wafer to adhere temporarily to the toothpick. Such a procedure
minimizes mechanical damage to the wafer, but is unsatisfactory for
a number of obvious reasons including poor control over the
position of the wafer and poor control over the disengagement of
the wafer from the toothpick.
Another prior art device is a pencil-size device which employs a
vacuum to pick up a silicon chip, the device having a short pick-up
nozzle at the end of an air passage in communication with a
suitable vacuum source. The air passage has a radial vent port and
when the vent port is closed by the index finger or by a leaf
spring which is depressed by the index finger, a vacuum is created
to cause the small object to adhere to the nozzle. The small object
is released by lifting the finger to vent the air passage to the
atmosphere. Unfortunately, relieving the instrument of the pressure
of the index finger for the purpose of terminating the vacuum tends
to destroy the stability of the instrument, the nozzle tending to
swing upwardly. A further disadvantage is that too often the small
object continues to adhere to the nozzle after the vacuum is
destroyed.
SUMMARY OF THE INVENTION
The objects of the invention include: to provide a vacuum-actuated
pencil-size instrument of a cross sectional configuration that is
conducive to stability of the device when it is gripped by the
fingers; to provide such an instrument in which a forwardly
extending pick-up nozzle is of substantial length to keep the
fingers from interfering with observation of a small object on the
nozzle tip and with the nozzle curved downwardly in a vertical
plane through the axis of the instrument to place the end of the
nozzle near to the line of sight of the operator; to provide such
an instrument with quickly interchangeable nozzles for different
specific tasks; to provide interchangeable nozzles that are
relatively inexpensive and are of various diameters including
extremely small diameters; to provide such a nozzle with a plastic
pick-up sleeve on its end that is yieldable to avoid damage to
delicate objects and to make air-tight engagement with small
objects; to provide such an instrument in which the nozzle tip may
be manually rotated by a finger wheel on the instrument body for
the purpose of turning a small object to a desired orientation or
for the purpose of screwing a small object into its assembled
position; to provide a satisfactory degree of rotational
responsiveness of the nozzle to a given increment of rotation of
the finger wheel, the ratio of rotation of the nozzle tip to
rotation of the finger wheel being high enough for rapid initial
rotation of a small object to approximately a desired orientation
and the ratio being small enough to facilitate precise final
orientation of the object; to provide efficient mechanical means
for transmitting motion from the finger wheel to the relatively
remote tip of the curved nozzle; to provide a vacuum-actuated
instrument without the necessity of connecting the instrument to a
vacuum source, thus eliminating a flexible hose that might
interfere with free maneuvering of the instrument; to control the
vacuum in the pick-up nozzle by means of a valve member in the form
of a slide that may be easily and quickly operated by the index
finger; to provide such an arrangement in which the finger wheel
may also be actuated by the index finger; to provide such an
instrument in which the slide valve may be actuated by the index
finger and the finger wheel may be independently actuated by the
third finger of the hand; to provide such an instrument which may
be employed either as a left hand instrument or a right hand
instrument with actuation of the finger wheel in both instances by
the third finger of the hand; to provide a valve means that is
effective to eliminate the tendency for small objects to adhere to
the nozzle after the vacuum is broken; to provide such an
instrument wherein not only nozzles may be employed
interchangeably, but also tail pieces may be employed
interchangeably to enable the instrument to be employed either with
a vacuum hose or with an independent vacuum reservoir built into
the instrument; and to provide novel functions for the vacuum in
the instrument, the functions including: to form effective seals at
various points of the instrument; to tend to hold parts of the
instrument in their assembled positions; and to serve the purpose
of spring means to maintain a valve member in frictional contact
with a fixed guide surface.
The various objects, features and advantages of the invention may
be understood from the following detailed description and the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, which are to be regarded as merely
illustrative:
FIG. 1 is a side elevation of a first rotary-nozzle embodiment of
the invention with a portion of the instrument broken away;
FIG. 2 is a top plan view of the instrument;
FIG. 3 is an enlarged fragmentary longitudinal section taken as
indicated by the line 3--3 of FIG. 2;
FIG. 4 is a greatly enlarged fragmentary section of the nozzle
assembly as seen along the line 4--4 of FIG. 3;
FIG. 5 is a transverse section along the line 5--5 of FIG. 4;
FIG. 6 is a diagram showing how a flat silicon chip or wafer
adhering to the tip of the nozzle may be rotated to various
orientations by the finger wheel on the body of the instrument;
FIG. 7 is an enlarged transverse section along the line 7--7 of
FIG. 3 showing the finger wheel and associated gearing;
FIG. 8 is an enlarged transverse section along the line 8--8 of
FIG. 3 showing how the slide valve is positioned in a longitudinal
guideway;
FIG. 9 is a fragmentary section along the line 9--9 of FIG. 7
showing how the finger wheel meshes with a driven gear on the rear
end of a forwardly extending tubular drive shaft for rotation of
the nozzle tip;
FIG. 10 is a longitudinal sectional view of a fixed-nozzle
embodiment, the slide valve being shown in a position for
connecting the fixed nozzle to a vacuum hose that extends
rearwardly to a suitable vacuum source;
FIG. 11 is a sectional view of the same embodiment similar to FIG.
10 showing the slide valve in a position to cut off the nozzle from
the vacuum hose in a manner to maintain the vacuum in the nozzle
for the purpose of causing a small object to adhere to the tip of
the nozzle;
FIG. 12 is a similar sectional view showing the slide valve in its
third forward limit position at which the slide valve vents the
nozzle to the atmosphere for the purpose of releasing a workpiece
from the tip of the nozzle;
FIG. 13 is a fragmentary plan view of a second rotary-nozzle
embodiment of the invention, a portion of the body of the
instrument being broken away to reveal gearing associated with the
finger wheel;
FIG. 14 is an enlarged fragmentary longitudinal section taken along
the line 14--14 of FIG. 13 showing gearing associated with the
finger wheel;
FIG. 15 is a transverse section along the line 15--15 of FIG. 14
which shows the structure of the finger wheel;
FIG. 16 is a transverse section along the line 16--16 of FIG. 14
showing in section an idler gear that meshes with a driven gear on
the rear end of a forwardly extending tubular drive shaft;
FIG. 17 is a fragmentary longitudinal horizontal section of a third
rotary-nozzle embodiment of the invention;
FIG. 18 is an enlarged transverse section along the line 18--18 of
FIG. 17 showing how a finger wheel protrudes at opposite sides of
the body of the instrument;
FIG. 19 is a side elevation of another fixed-nozzle embodiment of
the invention;
FIG. 20 is an enlarged fragmentary longitudinal vertical section of
the instrument shown in FIG. 19;
FIG. 21 is a longitudinal sectional view of a detachable tail piece
for a vacuum type instrument wherein the tail piece serves as a
vacuum reservoir;
FIG. 22 is an enlarged fragmentary longitudinal section taken as
indicated on the line 22--22 of FIG. 21 to show the structure of a
check valve for the vacuum reservoir;
FIG. 23 is a fragmentary longitudinal section of a fourth
rotary-nozzle embodiment of the invention;
FIG. 24 is a cross section of FIG. 23 with internal structure
removed for clarity of illustration to show how the finger wheel
engages a driven gear on the rear end of a tubular drive shaft;
FIG. 25 is a fragmentary section taken along the line 25--25 of
FIG. 4 showing how the face of the finger wheel is provided with a
circumferential series of recesses for engaging the driven gear on
the rear end of the tubular drive shaft;
FIG. 26 is a view similar to FIG. 25 showing a different
configuration for the circumferential series of recesses in the
face of the finger wheel;
FIG. 27 is an enlarged fragmentary longitudinal section of a fifth
rotary-nozzle embodiment of the invention;
FIG. 28 is a transverse section of FIG. 27 with internal structure
omitted for clarity of illustration showing how the finger wheel
engages the driven gear on the rear end of the tubular drive
shaft;
FIG. 29 is a side elevation of the finger wheel in FIG. 27 showing
how the finger wheel is formed with peripheral teeth for engagement
with the driven gear on the rear end of the tubular drive
shaft;
FIG. 30 is an enlarged fragmentary sectional view of the sixth and
presently preferred rotary-nozzle embodiment of the invention;
FIG. 31 is a transverse section of FIG. 30 with internal structure
removed for clarity showing how the finger wheel is related to the
driven gear on the rear end of the tubular drive shaft; and
FIG. 32 is a side elevational view of the finger wheel as seen
along the line 32--32 of FIG. 30.
DESCRIPTION OF THE SELECTED EMBODIMENTS OF THE INVENTION
FIGS. 1-9 illustrate the first of the rotary-nozzle embodiments of
the invention. As shown in FIGS. 3 and 8, the main body portion of
the instrument that is grasped by the operator's fingers has a core
10 of circular cross sectional configuration and a surrounding
plastic sleeve 12 that is of generally triangular configuration,
the configuration providing a top longitudinal surface 14 that
extends across the full width of the instrument and two downwardly
convergent longitudinal side surfaces 15 and 16.
Referring to FIG. 3, the core 10 has a forward tubular extension 18
which is surrounded by a forward nose section 20 of the body. The
nose section 20 is of triangular cross section at its rearward end
where it is embraced and supported by the forward end of the
plastic sleeve 12, the nose section tapering forwardly and being
circular at its forward end.
As shown in FIG. 1, the rear end of the core 10 has a rearwardly
extending tubular portion 22 on which a rear section 24 of the body
is fixedly telescoped to engage and support the rear end of the
triangular plastic sleeve 12, the forward end of the rear section
24 being of trinagular cross sectional configuration with the rear
section tapering rearwardly to a reduced circular configuration.
The rear end of the rear section 24 of the body forms a reduced
nipple 25 onto which a tail fitting 26 is releasably threaded to
serve as an adapter for connecting the instrument to a flexible
hose 28 that is connected to a suitable vacuum source such as a
vacuum pump.
In the construction shown in section in FIG. 2 a nose fitting 30 is
screwed into the forward end of the tubular extension 18 of the
core 10 and this nose fitting forms a tapered nose 32 to receive
the socket end 34 of a nozzle assembly that is generally designated
35. Thus, the nozzle assembly fits releasably onto the nose fitting
30 in the same manner as the socket end of a hypodermic needle fits
releasably onto the nose of a hypodermic syringe.
The body of the instrument is comparable in size to a pencil, the
vertical cross sectional dimension of the sleeve 12 being, for
example, approximately one-half inch.
In the construction shown the socket end 34 of the nozzle assembly
is the socket end of a tubular shank 36 that has a downwardly
inclined end, the tubular shank being formed with a downward bend
that is in a vertical plane, i.e., in the vertical plane that
bisects the triangular cross sectional configuration of the sleeve
12. Rotatably mounted on the downwardly inclined end of the tubular
shank 36 is a straight tubular nozzle extension 38 which carries a
nozzle tip 40 of a suitable resiliently yieldable plastic material.
The nozzle tip 40 may be simply a short piece of medical plastic
tubing commonly used in blood vessel surgery, the tubing being
telescoped over the nozzle extension 38 and extending forward from
the nozzle extension. FIGS. 1, 2, 3, 4, and 6 show how a small
rectangular silicon chip or wafer 42 is releasably held against the
nozzle tip 40 by means of a vacuum inside of the nozzle tip
fitting.
The rotary nozzle extension 38 may be secured to the end of the
tubular shank 36 by a joint construction of the character shown in
FIG. 4. In FIG. 4 the tubular shank 36 has a circular radial flange
44 on its outer end and the nozzle extension 38 is fixedly
connected to a flanged fitting 45 that has a radial ear 48 with an
aperture 50 therein. Fixedly mounted in the flanged fitting 45 is a
piece of tubing 52 that telescopes into the tubular shank 36 in a
rotatable manner to serve as a bearing for the nozzle extension 38.
To provide a seal at the rotary joint between the fixed tubular
shank 36 and the rotary nozzle extension 38, a gasket 54 is
inserted between the faces of the radial flange 44 and the flange
fitting 45, the gasket being made of suitable plastic material
having a low coefficient of friction with respect to the two
faces.
The nozzle extension 38 with the nozzle tip 40 thereon is
operatively connected to suitable control means on the instrument
body for rotating the nozzle tip 40 by remote control. AS shown in
FIGS. 1, 2, 3, 7, and 9, the remote control means may comprise a
finger wheel 55 which protrudes through a slot 56 in the upper wall
of the plastic sleeve 12 to make the finger wheel accessible for
rotation by the index finger of the operator of the instrument. The
body core 10 is cut away as indicated at 58 in FIG. 7 to provide
room for the finger wheel 55 inside of the plastic sleeve. The
finger wheel is mounted on a suitable stud 60 that threads into the
body core and is accessible through an aperture 61 in the plastic
sleeve 12. In the construction shown, the finger wheel 55 functions
as a drive gear, the finger wheel having outer circumferential
teeth 62 that engage the teeth of a driven gear 64 which is
preferably made of plastic material. The driven gear 64 is fixedly
mounted on the rear end of a forwardly extending tubular drive
shaft 65 which is journalled on the tubular extension 18 of the
body core 10 and is surrounded by the nose section 20 of the
instrument body.
A radial flange 66 on the exposed forward end of the tubular drive
shaft 65 is operatively connected to a forward collar 68 that
rotatably embraces the tubular shank 36. In the construction shown,
the operative connection between the flange 66 and the rotary
collar 68 comprises a short piece of stiff wire 70 that is
permanently embedded in the collar 68. The stiff wire releasably
extends through an aperture 72 in the flange 66 to permit the
nozzle assembly to be withdrawn from the tapered nose 32 of the
instrument.
The operative connection between the rotatable collar 68 and the
nozzle extension 38 may comprise a snugly wound coil 74 of suitable
spring wire that rotatably embraces the bent tubular shank 36, as
best shown in FIG. 3, with one end 75 of the wire coil embedded in
the rotary collar 68. As shown in FIG. 4, the other end 76 of the
wire coil extends through the previously mentioned aperture 50 in
the ear 48 and overhangs the flanged fitting 45.
The means for controlling the creation of a vacuum in the nozzle
tip 40 may comprise, first, a forwardly extending axial passage 78
in the instrument body that communicates with the tubular shank 36,
second, a rearwardly extending axial passage 80 in the instrument
body that communicates with the vacuum hose 28 and, third, a slide
valve 82 that is cut away on its underside to provide a short third
passage 84 to interconnect the two passages 78 and 80.
The slide valve 82 is movable in a longitudinal guide channel 85 on
the upper side of the body core 10 with the forward passage 78
terminating in a first port 86 in the bottom of the guide channel
and with the rearward passage 80 terminating in a second port 88 in
the bottom of the guide channel. A serrated portion 90 of the slide
valve 82 protrudes through a longitudinal slot 92 in the upper wall
of the plastic sleeve 12 to make the slide accessible for
manipulation by the index finger of the operator of the instrument.
The plastic sleeve overhangs the forward and rear ends of the slide
valve 82 to keep the slide captive.
As may be seen in FIG. 2, the finger wheel 55 and the slide valve
82 are relatively close together with the range of longitudinal
movement of the slide valve overlapping the longitudinal extent of
the finger wheel. As may be seen in FIG. 8 the slide valve is in a
vertical plane that bisects the top longitudinal surface 14 of the
instrument and as may be seen in FIGS. 2 and 7, the finger wheel 55
is inclined from the vertical to provide clearance for the slide
valve, the angle of inclination of the finger wheel being
preferably approximately 12.degree..
In the construction shown, the forward air passage 78 has a vent
port 94 in the bottom of the guide channel 85 which is under
control of the slide valve 82. Preferably, the slide valve 82 is
provided with an aperture 95 which may register with the vent port
94 for the purpose of placing the forward air passage 78 in
communication with the atmosphere.
The slide valve 82 is movable to a rearward limit position abutting
the rear end of the sleeve slot 92 at which the short passage 84 of
the slide valve establishes communication between the forward air
passage 78 and the rearward passage 80 as may be seen in FIG. 3. At
a second intermediate position of the slide valve 82 the slide
valve covers the port 88 to cut off the rearward passage 80 and the
slide valve isolates the forward air passage 78 both from the
rearward air passage 80 and from the atmosphere to maintain a
vacuum in the forward passage and thus keep a picked up chip or
wafer 42 in engagement with the nozzle tip 40. The function of the
slide valve at this second intermediate position may be understood
by referring to FIG. 11.
A third position of the slide valve 82 is a forward limit position
against the forward end of the sleeve slot 92. At this third
position of the slide valve the aperture 95 of the slide valve
registers with the port 86 to vent the forward air passage 78 to
the atmosphere and thus terminate a vacuum in the tip fitting 40 to
release the chip or wafer 42. The third position of a slide valve
is shown in FIG. 12.
The manner in which the first embodiment of the invention functions
for its purpose may be readily understood from the foregoing
description. With the slide valve 82 at its first rearward limit
position shown in FIG. 3, the vacuum hose 28 is in communication
with the forward air passage 78 to evacuate air from the interior
of the nozzle tip 40 and when the nozzle tip is applied to a small
object 42 at this time for the purpose of picking up the object, a
vacuum is quickly created inside the nozzle tip 40 to cause the
object to adhere to the nozzle tip. The operator may then move the
slide valve 82 forward to its second intermediate position at which
it cuts off the forward passage 78 both from the vacuum hose 48 and
the atmosphere to maintain the vacuum in the nozzle tip 40
independently of the vacuum hose. The operator may then employ the
instrument as means for transporting the small object 42 to a
desired destination and the operator may manipulate the finger
wheel 55 to rotate the small object 42 to any desired orientation
of the destination. The operator may then push the slide valve 82
to its forward limit position to vent the forward air passage 78 to
the atmosphere and thus terminate the vacuum inside the nozzle tip
40 to cause the nozzle tip to release the small object.
FIGS. 10, 11, and 12 show the construction of a simplified
embodiment of the invention that has a fixed nozzle tip 115 instead
of a rotatable nozzle tip.
The body of the instrument shown in FIGS. 10, 11, and 12 has a core
100 which is fixedly embraced by a forward collar 102 and a
rearward collar 104. A plastic sleeve 105 which is supported at its
opposite ends by the two collars has a longitudinal slot through
which a slide valve 108 extends for manipulation by the index
finger of the operator of the instrument. A rear body section 110
that threads onto the core 100 is formed with a rearwardly
extending nipple 112 for connection to a vacuum hose 28.
The body of the instrument is formed with the usual forward axial
passage 114 that communicates with a nozzle tip 115 and the body is
provided with the usual rearwardly directed axial passage 116 that
communicates with the vacuum hose 28. The forward passage 114
terminates at its rear end in a port 118 under the slide valve 108
and in like manner the rear passage 116 terminates in a port 120
under the slide valve, the slide valve being cut away on its
underside to provide the usual short passage 122 for placing the
two passages 114 and 116 in communication with each other. A
tubular nozzle shank 123 of the usual bent configuration is fixedly
mounted in the forward end of the body core 100 and the nozzle tip
115 is telescoped onto the leading end of the tubular shank. The
forward air passage 114 has the usual vent port 124 and the slide
valve 108 has the usual aperture 125 to cooperate with the vent
port.
It is apparent that the simplified instrument shown in FIGS. 10,
11, and 12 functions in the same general manner as the first
embodiment of the invention except for the fact that the nozzle tip
115 is not rotatable for the purpose of orienting a small object
adhering thereto.
FIGS. 13-16 illustrate a second embodiment of a rotary-nozzle type
of pick-up instrument which is largely similar to the first
embodiment as indicated by the use of corresponding numerals to
indicate corresponding parts. This embodiment differs from the
first embodiment solely in the finger wheel and associated gearing
for manually rotating the tubular drive shaft 65. As shown in FIGS.
14 and 16, an idler gear 130 on a stub axle 132 is in mesh with the
driven gear 64 on the tubular drive shaft 65 and is also in mesh
with a drive gear 134 that is integral with a smooth-rimmed finger
wheel 135. The finger wheel 135 is journalled on a stud 136 that is
threaded into a body core 138. A plastic sleeve 140 of the
instrument body has an aperture 142 for access to the stud 136 and
has a longitudinal slot 144 through which the smooth-rimmed finger
wheel 135 protrudes for manipulation by the index finger of the
user. As shown in FIG. 13, the instrument has the usual slide valve
145 to control the vacuum in the pick-up nozzle. The instrument
operates in the same manner as the first embodiment of the
invention.
FIGS. 17 and 18 illustrate a third rotary-nozzle pick-up instrument
that is also similar to the first embodiment, differing solely in
the means of manual rotation of the tubular drive shaft 65. In the
construction shown, the driven gear 64 on the rear end of the
tubular drive shaft 65 is engaged by a drive gear 148 that rotates
in unison with a smooth-rimmed finger wheel 150. The drive gear 148
is journalled on a block 152 that is inserted into a body core 154
of the instrument and the finger wheel 150 is journalled on a stud
155 that is threaded into the end of the insert and is aaccessible
through an aperture 156 in a plastic sleeve 158 of the body of the
instrument. The drive gear 148 and the finger wheel 150 are
separate members which are interlocked by radial serrations 159 on
their confronting faces.
A feature of the embodiment shown in FIGS. 17 and 18 is that the
finger wheel 150 is on the bottom side of the body core 154 and
protrudes by equal amounts through longitudinal slots 160 in the
two convergent side walls of the plastic sleeve. Thus, with the
finger wheel 150 spaced below the slide valve 162 of the instrument
the finger wheel may be manipulated by the third finger of the
operator's hand instead of the index finger.
FIGS. 19 and 20 show another embodiment of the invention that has a
fixed or nonrotary pick-up nozzle. The body of the instrument is
quite similar in construction to the body of the instrument shown
in FIGS. 1-9 as indicated by the use of corresponding numerals to
indicate corresponding parts. The tubular drive shaft 65 of the
first embodiment of the invention is replaced by a fixed spacer
sleeve 165. The usual nose fitting 30 is threaded into the end of a
tubular extension 18a of the body core 10a to receive the socket
end 34a of the tubular shank 36a of a nozzle assembly 38a. The
nozzle extension 38a is fixedly mounted in the end of the tubular
shank 36a and carries a previously described plastic nozzle tip 40.
It is apparent that a number of nozzle assemblies of different
sizes may be mounted interchangeably on the nose fitting 30.
Referring back to FIG. 1, the tail fitting 26 that is attached to
the vacuum tube 28 may be removed from the body to expose the
nipple portion 25 of the rear body section 24 so that a module
differing from the tail fitting 26 may be attached to the rear
section 24. By way of example, FIG. 21 shows how a module 170 may
be substituted for the tail fitting 26 of FIG. 1 or the tail
fitting 26a of FIG. 19. The module 170 forms a chamber 172 that is
closed at its rear end by a removable bushing 174 that is equipped
with a sealing gasket 175. The bushing 174 is provided with an
axial threaded tubular valve body 176 that houses a check valve
structure similar to the familiar check valve structure employed in
automobile tires. When the tubular valve body 176 is screw
threadedly engaged with means for connecting the tubular valve body
to a vacuum pump, the valve member in the valve body 176 opens in
response to the connection to permit the vacuum pump to evacuate
the chamber 172. When the chamber 172 is adequately evacuated the
connection is removed from the tubular valve body 176 to permit the
check valve to close to keep the chamber 172 evacuated. Obviously,
the coiled valve spring 180 that biases the valve stem 182 to
closed position must be strong enough to withstand a pressure
differential as high as 15 psi. The chamber 172 has an axial
passage 178 that communicates with the usual rearward air passage
80 of the body core of the instrument.
In FIGS. 23, 27, and 30 a modified slide valve 185 is shown which
differs from the previously described slide valves in the provision
for venting the pick-up nozzle. Instead of providing the slide
valve with an aperture therethrough to register with a vent port 95
in the body core of the instrument, the slide valve 185 is provided
with an angular vent passage 186 that registers with the vent port
at the forward limit position of the slide. One advantage of the
modified slide valve is that there is no possibility of the
operator's index finger blocking the inflow of atmospheric air into
the pick-up nozzle. Another advantage is that the angular vent
passage 186 communicates with the interior of the instrument body
and does so when the slide is in a forward position that closes the
forward end of the slot 188 in the plastic sleeve through which the
slide protrudes. Thus, since the angular vent passage 186 draws
atmospheric air from the interior of the plastic sleeve there is
less likelihood of dust or other small particles being drawn from
the atmosphere into the pick-up nozzle.
The fourth rotary-nozzle embodiment of the invention shown in FIGS.
23-25 differs from the embodiment shown in FIGS. 17, 18 solely in
the above described modification of the slide valve and in the
manner in which a tubular drive shaft 65a is rotated by a
smooth-rimmed finger wheel 190. The finger wheel 190 which is
journalled on a stud 192 is formed with a concentric series of
equally spaced recesses 194 on one of its faces to engage the teeth
of a driven gear 64a that is fixedly mounted on the rear end of the
tubular drive shaft 65a. FIG. 26 shows how a concentric series of
round recesses 195 may be employed instead of the recesses 194
shown in FIG. 25.
FIGS. 17-29 illustrate a fifth rotary-nozzle embodiment of a
pick-up instrument which differs from the embodiment shown in FIGS.
23-25 solely in the manner in which a driven gear 64 on the end of
a tubular drive shaft 65 is manually actuated. As shown in FIG. 27
a finger wheel 198 which is mounted on the bottom side of a body
core 200 by means of a stud 202 has peripheral teeth 204 that
engage the driven gear 64, the peripheral teeth being of the
profile shown in FIG. 29.
FIGS. 30-32 illustrate a further embodiment of the rotary nozzle
pick-up instrument in which a smooth-rimmed finger wheel 210 is
journalled on a stud 212 on the underside of a body core 214 of the
instrument. The finger wheel 210 has a concentric series of axially
projecting teeth 215 on its inner face which serve as a drive gear
in mesh with a driven gear 64b on a tubular drive shaft 65b.
EXPLANATION OF FEATURES OF THE INVENTION
The triangular cross sectional configuration of the body of the
instrument enables the operator to grip the instrument by his
fingers in a manner that prevents the instrument from turning on
its axis and ensures that the controls that are manipulated by the
index finger are on the upper side of the instrument body.
An important feature of the invention is that the triangular cross
sectional configuration results in stability of the instrument
because the finger pressure against each of the three longitudinal
surfaces of the instrument body is balanced by finger pressure
against each of the other two longitudinal surfaces. Thus, the
downward pressure of the index finger on the upper side of the
instrument is balanced by the opposing pressures of the thumb and
the second finger against the two downwardly divergent sides
respectively. With the index finger constantly pressing downward
against the slide valve, the manipulation of the slide valve does
not destroy the stability of the instrument. In contrast, if the
index finger must be lifted from the instrument body to vent the
pick-up nozzle, stability is lost and the nozzle waivers at the
very moment when a small object is being released from the
nozzle.
An important advantage of mounting the finger wheel horizontally on
the underside of the instrument with the finger wheel accessible
from both sides, as shown in FIGS. 18, 24, 28, and 31, is that the
finger wheel may be manipulated with equal convenience by
right-handed and left-handed operators.
An important feature of the invention is based on the discovery of
why a previously mentioned vacuum-actuated instrument cannot be
relied upon to release a small object when the finger-controlled
vent port of the instrument is opened for that purpose. The vent
port is in the single axial passage of the instrument which is in
continuous communication with a vacuum source. The discovery is
that the portion of the axial passage that extends forward from the
vent port to the nozzle tip must compete for atmospheric air with
the rearward portion of the passage that communicates with the
vacuum source and consequently the vacuum is only partially
destroyed at the nozzle tip. Actually, the open port tries to vent
the vacuum source itself and therefore cannot effectively vent the
nozzle tip.
The invention takes advantage of this discovery by cutting off the
rearward portion of the axial passage so that only the forward
portion of the passage is vented to the atmosphere. Thus, a feature
of the invention is that the slide valve cannot be shifted to the
forward venting position without first cutting off the vacuum
source, the result being that the vacuum at the nozzle tip is
abruptly destroyed for effective release of the small object. There
is also reason to believe that in the new arrangement atmospheric
air enters the nozzle tip so abruptly that it gains sufficient
momentum to create momentary positive pressure against the inner
face of the small object to ensure prompt release of the small
object.
The employment of a resiliently deformable tubular nozzle tip is
advantageous on two counts. In the first place, the nozzle tip is
sufficiently soft to avoid scratching a small object that is highly
vulnerable to damage and, in the second place, the plastic nozzle
tip yieldingly conforms to the surface configuration of the small
object to form an air-tight seal at the juncture of the small
object and the nozzle tip.
With the nozzle extending forward from the instrument body and
curving downwardly towards the tip of the nozzle, and with the
triangular cross sectional configuration of the body preventing
rotation of the nozzle in the operator's hand, the curved nozzle is
maintained in approximately a vertical plane with the end of the
nozzle extending relatively close to alignment with the line of
sight of the operator of the instrument.
With a slide valve and a finger wheel relatively close together on
the upper longitudinal side of the instrument body, the index
finger may be quickly shifted from one control to the other. Since
the finger pressure against the finger wheel is balanced by the
pressure of the thumb and second finger against the convergent
lower sides of the instrument body, the instrument is held in a
stable manner during the rotation of a small object to a desired
orientation. In like manner, since the pressure of the index finger
is balanced by the pressure against the convergent lower sides of
the instrument body when the index finger moves the slide valve
forward to terminate the vacuum, there is no tendency for the tip
of the nozzle to waiver at the moment when a small object is being
released. It is also to be noted that the heel of the operator's
hand may rest on a table or counter where the assembly operation is
being carried out, the support of the hand making it possible to
keep the nozzle tip steady.
The provision for rotating the nozzle tip by remote control from
the body of the instrument together with the provision of a
relatively long nozzle makes it possible to keep the operator's
fingers and the leading end of the instrument body out of the field
of vision at the nozzle tip. This feature is especially important
in the common practice of employing a microscope, for example, a 40
power microscope to carry out an assembly operation.
The location of a finger wheel on the underside of the instrument
body as shown in FIGS. 18, 23, 27, and 30 makes possible
independent manipulation of the slide valve and the finger wheel by
the operator's index finger and third finger respectively. Thus,
this arrangement promotes stability of the instrument by making it
unnecessary for the operator to shift his index finger back and
forth between the slide valve and the finger wheel.
For the further promotion of stability of the instrument, the
provision of a vacuum reservoir as illustrated by FIG. 21 frees the
body of the instrument from the weight and drag of a flexible
vacuum hose.
In the design of the instrument, advantage is taken of the fact
that the instrument employs a vacuum to pick up small objects. In
the first place, the invention utilizes the vacuum to create a
vertical pressure differential across the slide valve that presses
the slide valve against the bottom wall of its guideway. Thus, the
arrangement makes it unnecessary to employ any kind of spring means
to press the slide valve against its guideway to ensure a required
degree of frictional resistance to movement of the slide valve. In
the second place, the vacuum promotes sealing contact between
various parts to make it possible to simplify the construction of
the instrument. Thus, the vacuum promotes sealing action at the
slide valve, sealing action at the rotary joint in the nozzle
assembly, sealing action where the plastic tip embraces the nozzle
extension 38, and sealing action between the plastic tip and a
small object that is picked up by the tip.
In the third place, the vacuum in the instrument has the effect of
urging certain parts to their assembled positions. Thus, the vacuum
in the forward part of the instrument tends to keep the nozzle
assembly connected to the instrument body and, as may be seen in
FIG. 4, the vacuum tends to draw the nozzle extension 38 towards
the tubular shank 36 of the nozzle to keep the two parts
together.
The employment of a relatively long tubular drive shaft for
transmitting rotation from the finger wheel to the instrument
nozzle makes it possible to position the finger wheel sufficiently
rearwardly to be in close proximity to the slide valve.
The provision of the coil spring makes it possible to transmit
rotation from the tubular drive shaft past the bend in the nozzle
to the rotatable nozzle tip and the coil spring does not interfere
with the field of vision at the nozzle tip. The inclusion in the
motion-transmitting means of the short rigid wire 70 as shown in
FIG. 3 makes the rotary nozzle assembly detachable to permit the
use of different rotary nozzle assemblies interchangeably.
The use of a finger wheel with peripheral gear teeth as in FIGS. 2
and 27 makes possible simplification of the nozzle-rotating
mechanism. On the other hand, a finger wheel with a smooth surface
as shown in FIGS. 15, 18, 23, and 30 is more comfortable for the
user and is highly desirable when the instrument is manipulated
constantly over a period of several hours.
As heretofore stated, it is desirable on the one hand that the
rotary nozzle tip be highly responsive to rotation of the finger
wheel for initial rotation of a small object to approximately the
desired orientation of the small object and, on the other hand, it
is desirable that the rotary nozzle tip be less responsive to the
finger wheel in carrying out precisely the final orientation of the
small object. It has been found that a satisfactory compromise is
to arrange for approximately one-eighth inch peripheral movement of
the finger wheel to cause the nozzle tip to rotate through an angle
of 30.degree.-60.degree.. In designing the instrument it is a
simple matter to select the diameter of the finger wheel and the
gear ratio between the finger wheel and the tubular shaft to
provide any desired angular response to one-eighth inch peripheral
movement of the finger wheel. In the above embodiments of the
rotary-nozzle instruments the angular response is in the range of
30.degree.-60.degree., a response of approximately 40.degree. being
preferred.
Economical fabrication of the various embodiments of the invention
is favored in different ways. A basic body structure is employed
for the various rotary nozzle embodiments, a basic body core being
cut away in various ways for various types of finger wheels and
associated gearing. The same basic body structure is used for the
fixed nozzle embodiment shown in FIGS. 19 and 20 wherein the fixed
tubular spacer 165 is substituted for the usual tubular drive shaft
18. Any of the described embodiments of the invention that is
connected to a vacuum source by a flexible vacuum tube may be
converted to a model that incorporates a vacuum reservoir by simply
substituting the vacuum reservoir shown in FIG. 21 for the usual
tail fitting 26.
My description in specific detail of the selected embodiments of
the invention will suggest various changes, substitutions, and
other departures from my disclosure within the spirit and scope of
the appended claims.
* * * * *