U.S. patent application number 09/765010 was filed with the patent office on 2001-09-13 for jaw tips and jaw tip assemblies for parts grippers.
Invention is credited to Moilanen, Steven M., Steele, Kenneth.
Application Number | 20010020791 09/765010 |
Document ID | / |
Family ID | 26783744 |
Filed Date | 2001-09-13 |
United States Patent
Application |
20010020791 |
Kind Code |
A1 |
Moilanen, Steven M. ; et
al. |
September 13, 2001 |
Jaw tips and jaw tip assemblies for parts grippers
Abstract
A set of angled gripper jaw tips. Each jaw tip has a gripping
surface that is complimentarily angled to the other jaw tip. The
gripping surfaces become substantially coplanar when closed
together.
Inventors: |
Moilanen, Steven M.; (Fort
Wayne, IN) ; Steele, Kenneth; (Fort Wayne,
IN) |
Correspondence
Address: |
BARNES & THORNBURG
600 One Summit Square
Fort Wayne
IN
46802
US
|
Family ID: |
26783744 |
Appl. No.: |
09/765010 |
Filed: |
January 18, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09765010 |
Jan 18, 2001 |
|
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09345031 |
Jun 30, 1999 |
|
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60091232 |
Jun 30, 1998 |
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Current U.S.
Class: |
294/203 |
Current CPC
Class: |
Y10S 294/902 20130101;
B25J 15/0475 20130101 |
Class at
Publication: |
294/88 |
International
Class: |
B65G 015/04 |
Claims
What is claimed is:
1. A set of opposable angled gripper jaw tips which comprises: a
first jaw tip; a base formed on the first jaw tip; a central axis
disposed through the first jaw tip substantially perpendicular to
the base; a gripping surface integral with the first jaw tip; the
gripping surface is formed non-perpendicular to the central axis of
the first jaw tip; a second jaw tip; a base formed on the second
jaw tip; a central axis disposed through the second jaw tip
substantially perpendicular to the base; and a gripping surface
integral with the second jaw tip; the gripping surface is formed
non-perpendicular to the central axis of the second jaw tip; the
gripping surfaces of the first and second jaw tips are also
complimentarily angled so that they become substantially coplanar
when closed together.
2. The set of opposable angled gripper jaw tips of claim 1, wherein
the gripping surfaces of the first and second jaw tips each have a
diamond point structure.
3. The set of opposable angled gripper jaw tips of claim 1, wherein
the gripping surface of the first jaw tip is aligned at 45 degrees
with respect to the central axis thereof.
4. A gripper assembly comprising first and second opposable jaw
members, each having a tip seat, each tip seat being substantially
parallel to one another when the jaw members are in a closed
position, the gripper assembly also having a set of opposable
angled gripper jaw tips, the opposable angled gripper jaw tips
comprising: a first jaw tip coupled to the tip seat of the first
opposable jaw member; a gripping surface integral with the first
jaw tip; the gripping surface oriented non-parallel to the tip
seat; a second jaw tip coupled to the tip seat of the second
opposable jaw member; and a gripping surface integral with the
second jaw tip; he gripping surface oriented non-parallel to the
tip seat; the gripping surfaces of the first and second jaw tips
are complimentarily angled so that they become substantially
coplanar when closed together.
5. The opposable angled gripper jaw tips of claim 4, each further
comprising a base, each base abuts the tip seat of the jaw members,
respectively, and each base has an alignment structure which allows
the jaw tips to be mounted in different orientations with respect
to the jaw members.
6. The opposable angled gripper jaw tips of claim 5, when mounted
in different orientations with respect to the jaw members, the
gripping surfaces of the jaw tips remain complimentarily angled so
that they become substantially coplanar when closed together.
7. The opposable angled gripper jaw tips of claim 4, wherein the
gripping surfaces of the first and second jaw tips each have a
diamond point structure that is coplanar to one another when the
jaw tips are closed together.
8. A gripper assembly for holding a workpiece comprising: first and
second jaw members; each of the jaw members having a tip seat; each
tip seat is parallel to one another when the jaw members are in a
closed position; a set of opposable gripper jaw tips, the jaw tips
comprising: a first jaw tip coupled to the tip seat of the first
jaw member; a gripping surface integral with the first jaw tip; the
gripping surface oriented non-parallel to the tip seat; a second
jaw tip coupled to the tip seat of the second jaw member; a
gripping surface integral with the second jaw tip; the gripping
surface oriented non-parallel to the tip seat; the gripping
surfaces of the first and second jaw tips are complimentarily
angled so that they become substantially coplanar when in a closed
position.
9. The gripper assembly of claim 8, wherein the jaw tips are
configured to hold the workpiece at an angle non-parallel to the
tip seats without having to move the gripper assembly to that
angle.
10. The gripper assembly of claim 9, wherein the jaw tips are
replaceable with a second set of jaw tips having gripping surfaces
that are parallel to the tip seats.
11. A gripper assembly comprising: a driver movable within a plane;
a pair of opposable jaw members; at least one of the pair of
opposable jaw members is movable in response to movement of the
driver; a pair of angled tips; each of the angled tips is attached
to one of the opposable jaw members; a gripping surface is formed
on each of the angled tips; and each gripping surface is
complimentarily angled to each other; each gripping surface is
oriented non-parallel and non-perpendicular relative to the plane;
each gripping surface becomes substantially coplanar to each other
when the jaw members are closed together.
12. A modular gripper assembly which comprises: a body having a
yoke structure defined at one end thereof by a pair of spaced-apart
wall members, and a fluid driven actuator at an opposite end, the
actuator defining a first plane; a pair of opposable jaw members,
at least one of the pair of opposable jaw members being pivotal
within a second plane, and each of the pair of opposable jaw
members having through-slots therein and being independently
removable and replaceable by other jaw members; a single cam pin
extending into the through-slots of each of the pair of opposable
jaw members; a linkage structure driven by the fluid driven
actuator and coupled to the single cam pin between the pair of
opposable jaw members along a direction which is substantially
perpendicular to the second plane; and a pair of tip ends which are
aligned with one another; in each tip end includes a gripping
surface complimentarily angled non-parallel to the first plane
defined by the actuator, and the gripping surfaces become
substantially coplanar to each other when the j aw members are in a
closed position.
13. The modular gripper assembly of claim 12, wherein the base of
each of the first and second jaw tips has alignment structure which
allows the first and second jaw tips to be mounted in different
orientations with respect to gripper assembly.
Description
RELATED APPLICATION
[0001] This application is based upon U.S. Provisional Application
Ser. No. 60/091,232, filed Jun. 30, 1998, and is a divisional of
U.S. Utility patent application Ser. No. 09/345,031, filed Jun. 30,
1999, the complete disclosures of which are hereby expressly
incorporated by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to fluid pressure actuated
grippers of the type employed in automated workpiece handling
devices which clampingly grip and transfer a workpiece from one
station to another. More particularly, the present disclosure
relates to jaw tip designs and jaws tip assemblies for fluid
pressure actuated grippers.
BACKGROUND AND SUMMARY
[0003] Fluid pressure actuated grippers are widely employed and
typically take the form of a pneumatic or hydraulic differential
motor whose cylinder is fixedly mounted to a transfer device. At
the forward or rod end of the cylinder housing, a gripper jaw
mounting structure is fixedly mounted on the cylinder to pivotally
support a pair of opposed gripper jaws which are coupled to the
piston rod of the motor by a linkage so arranged that upon movement
of the piston in one direction the jaws are pivoted to an open
position and upon movement of the piston in the opposite direction
the jaws are driven to a closed workpiece gripping position.
[0004] In typical operation, the gripper jaws will be closed upon a
workpiece near the edge of the workpiece and the gripper will be
advanced to position the gripped workpiece in operative
relationship with a work station. The gripper will then be opened
to release the workpiece and the transfer device will retract the
gripper from the work station while the work operation is
performed. At the conclusion of the work operation, the gripper
will then advance back into the work station and the jaws will
again close upon the workpiece and carry it away from the work
station. Opening and closing the gripper jaws thus takes place when
the gripper is in its closest proximity to tooling at the work
station.
[0005] There are basically two types of linkage arrangements used
in fluid pressure actuated grippers to connect the gripper jaws to
the piston rods and effect movement of the gripper jaws. These are
pivotable link arrangements and pivotal cam arrangements. An
example of a pivotal link arrangement can be found in U.S. Pat. No.
5,152,568 to Blatt which discloses pivotal links 36 and 40 that
cooperate with gripper jaws 12A and 12B as shown in FIG. 3.
[0006] U.S. Pat. No. 4,518,187 to Blatt, et al. discloses a pivotal
cam arrangement in which jaw plates 45 and 47 are pivoted by the
cooperation of cam slots 61 provided in the jaw plates and a pivot
pin 37 (and rollers 39) attached to the piston rod.
[0007] Fluid pressure actuated grippers are generally designed for
use with particular workpieces to be transferred and with specific
work stations. For example, some workpieces and/or work stations
may require wider or narrower gripper jaws, different types of
gripper jaws, gripper jaws that open at different angles, different
clearance requirements, etc.
[0008] The present disclosure is directed to gripper jaw tips and
jaw tip assemblies for fluid pressure actuated grippers which allow
for the gripping, sensing and transferring of a variety of
workpieces.
[0009] According to other features, characteristics, embodiments
and alternatives of the present disclosure which will become
apparent as the description thereof proceeds below, the present
disclosure provides a set of opposable gripper jaw tips which
includes:
[0010] a first jaw tip having a base and a spherical concave
gripping surface; and
[0011] a second jaw tip having a base and a spherical convex
gripping surface,
[0012] the spherical concave gripping surface of the second jaw tip
being complimentarily shaped with the spherical concave gripping
surface of the first jaw tip.
[0013] The present disclosure also provides a set of opposable
angled gripper jaw tips which includes:
[0014] a first jaw tip having a base, a central axis, and a
gripping surface which is non-perpendicular to the central axis;
and
[0015] a second jaw tip having a base, a central axis, and a
gripping surface which is non-perpendicular to the central
axis,
[0016] the gripping surfaces of the first and second jaw tip being
complimentarily angled so that they become substantially coplanar
when closed together.
[0017] The present disclosure further provides a parts gripper
sensor mounting assembly which includes:
[0018] a gripper jaw tip having a gripping surface, a side and a
sensor bracket alignment structure; and
[0019] a sensor mounting bracket which includes a sensor mounting
structure, and an aligmnent structure which cooperates with the
sensor bracket alignment structure so as to align the sensor
mounting structure with the gripping surface of the jaw tip.
[0020] The present disclosure further provides a parts gripper
sensor mounting assembly which includes:
[0021] a gripper jaw tip having a gripping surface, a structure for
mounting the gripper jaw tip to a gripper jaw member, and a
recessed portion in the gripping surface for receiving a sensor
element therein.
[0022] The present disclosure still further provides a gripper tip
extender which includes:
[0023] a base configured to be coupled to a gripper jaw tip seat;
and
[0024] at least one arm member which extends outward from the base,
each of said at least one arm member including a plurality of
gripper tip receiving openings.
[0025] The present disclosure still further provides a padded
gripper tip which includes:
[0026] a base; and
[0027] a pad coupled to the base, the pad including a gripping
surface with a plurality of surface channels which are arranged in
a pattern for directing fluids away from the gripping surface.
BRIEF DESCRIPTION OF DRAWINGS
[0028] The present disclosure will be described hereafter with
reference to the attached drawings which are given as non-limiting
examples only, in which:
[0029] FIG. 1 is an exploded perspective view of a fluid actuated
gripper assembly.
[0030] FIGS. 2a and 2b are side and end views of a convex gripper
jaw tip according to one embodiment of the present disclosure.
[0031] FIGS. 3a and 3b are side and end views of a concave gripper
jaw tip according to one embodiment of the present disclosure.
[0032] FIG. 4 is a perspective view of a concave gripper jaw tip
which depicts how the tip is received in a gripper jaw member.
[0033] FIG. 5 is a perspective view of angled gripper jaw tips
which depicts how the tips are received in a gripper jaw
member.
[0034] FIGS. 6a and 6b are side views of the gripper jaw tips of
FIG. 5 which depict alternative ways of aligning the gripper jaw
tips.
[0035] FIG. 7 is an exploded view of a gripper tip assembly which
includes a workpiece sensor.
[0036] FIG. 8a is a side view of a gripper assembly having the
workpiece sensor of FIG. 7.
[0037] FIG. 8b is a top view of a gripper assembly having the
workpiece sensor of FIG. 7.
[0038] FIG. 8c is an end view of a gripper assembly having the
workpiece sensor of FIG. 7.
[0039] FIG. 9 is a perspective view of a gripper tip which has been
notched out and configured to receive a sensor in the face
thereof.
[0040] FIG. 10 is an exploded view of a gripper jaw tip assembly
which includes a tip extender that can be used to extend the
working length of gripper tips.
[0041] FIG. 11 is an exploded view of a gripper jaw tip assembly
which includes a tip extender that can be used to extend the
working width of gripper tips.
[0042] FIG. 12a is a cross-sectional side view of a padded gripper
tip having fluid expelling channels.
[0043] FIG. 12b is an end view of the padded gripper tip of FIG.
12a.
[0044] FIG. 12c is a side view of the padded gripper tip of FIG.
12a.
[0045] FIG. 13a is a cross-sectional side view of another padded
gripper tip having fluid expelling channels.
[0046] FIG. 13b is an end view of the padded gripper tip of FIG.
13a.
[0047] FIG. 13c is a side view of the padded gripper tip of FIG.
13a.
DETAILED DESCRIPTION OF THE DRAWINGS
[0048] The present disclosure is directed to jaw tips and jaw tip
assemblies for fluid pressure actuated grippers which allow for the
gripping, sensing and transferring of a variety of workpieces. The
jaw tips of the present disclosure are designed to allow for the
gripping, transportation, and handling of workpieces that are flat
or planar, or which have other than flat or planar shapes,
including complex bent or curved shapes. The jaw tips of the
present disclosure are particularly useful for gripping,
transporting, and handling stamped or molded workpieces, although
not limited for use therewith.
[0049] The present disclosure is also directed to gripper jaw tips
which are designed to prevent or reduce the formation of
particulate that tend to flake or peel off workpieces at or near
the site they are gripped. Such flaking or peeling can occur due to
deformation of a workpiece.
[0050] The present disclosure is further directed to gripper jaw
tip assemblies which include sensors that can be used to sense the
presence or absence of a workpiece. Such sensors can be mounted
adjacent or within the gripper jaw tips or the gripper jaw itself.
Suitable sensors include mechanical sensors, magnetic sensors,
optical sensors, and sensors which detect electrical properties.
Mechanical sensors that are tripped or otherwise moved when
contacting a workpiece, and optical sensors can be used in
conjunction with metal and non-metal workpieces. Magnet sensors and
sensors that detect electrical properties such as conductance can
be used in conjunction with workpieces that are made from metal,
magnetizable materials, and electrically conductive materials.
[0051] The present disclosure is also directed to extenders for
gripper jaw tips which can be used to extend the reach of gripper
jaw tips. The tip extenders include bases which are configured to
be coupled to tip seats of gripper jaw members and one or more arm
members which extend from the bases. The arm members include
through-bores by which various gripper jaw tips can be coupled to
the tip extenders. According to one embodiment, the tip extenders
are configured so that the arm members thereof will extend forward
of gripper jaw members, thus increasing the forward reach of the
gripper jaw members. According to another embodiment, the tip
extenders are configured so that the arm members thereof will
extend outward from the sides of gripper jaw members, thus
increasing the sideways reach of the gripper jaw members. In
further embodiments, the tip extenders are configured so that the
arm members thereof extend from their respective bases in any
desired direction.
[0052] The present disclosure is further directed to padded gripper
jaw tips which are provided with fluid expelling channels in their
faces. The fluid expelling channels are configured to direct fluids
trapped between the faces of the padded jaw tips and a workpiece,
away from the contacting surfaces. During processing, some
workpieces or portions thereof may be coated with fluids such as
oils, cutting or machining fluids, corrosion protective coatings,
etc. The use of fluid expelling channels according to the present
disclosure will ensure that such fluid-coated workpieces are
tightly or securely grasped, by forcing the coated fluid away from
the contacting surfaces in much the same way as tire treads are
designed to channel surface water away from between tires and road
surfaces. The fluid expelling channels can have a number of
configurations that are useful for round, square and rectangular
tip pads.
[0053] The gripper jaw tips and tip assemblies of the present
disclosure will be described hereafter with reference to an
exemplary gripper assembly that includes gripper jaws having
stepped tip seats. It is to be understood that the gripper jaw tips
and tip assemblies that include sensors and sensor mounts are not
limited for use with any particular gripper assembly or any
particular gripper jaw design.
[0054] FIG. 1 is an exploded perspective view of a basic fluid
actuated gripper assembly. The gripper assembly depicted in FIG. 1
includes a body 1, a piston assembly 2, a jaw pivot pin 3 and a jaw
driver assembly. The piston assembly 2 includes piston 4, piston
seal 5, piston shaft 6, and piston shaft seal 7. The jaw driver
assembly includes cross piece 8 which is attached to piston shaft
6, cam pin 9 which is coupled to cross piece 8, jaw bushings 10
which are received in cam slots 11 of the jaw members 12, and
slider bushings 13 which are received in longitudinal slots 14
formed in the side walls of the yoke structure of the body 1. The
piston 4 is contained within a piston chamber that is formed in the
base of body 1 and sealed by plug 15. As the piston 4 moves under
the influence of fluid pressure, the cam pin 9 slides along cam
slots 11, causing the jaw members 12 to either open or close.
Impact plates 16 can be attached to the sides of the body 1 so that
they extend beyond the front of the body 1 and protect the body
from impact damage. Although the two jaw members 12 depicted in
FIG. 1 are not the same, it is to be understood that other jaw
members could be used including similar jaw members. FIG. 1 merely
depicts the structure of a basic gripper assembly for illustrative
purposes.
[0055] FIGS. 2a and 2b are side and end views of a convex gripper
jaw tip according to one embodiment of the present disclosure. As
depicted, the gripper tip of FIG. 2a includes abase 17 which is
depicted as having a hexagonal shape, a cylindrical portion which
extends from base 17 and includes a convex face 18, and a threaded
stud 19 which extends from the base 17 on an opposite side from the
convex face 18. The convex face 18 has a partial spherical shape
with a minimum radius of curvature of about 0.25 inches. In
practice, there is no upper limit to the radius of curvature of the
convex faces so long as flat facial surfaces are avoided. A
preferred minimum for the radius of curvature is about 0.40 to 0.50
inches. According to one embodiment which was found to be
particularly useful for purposes of the present disclosure, convex
faces having a radius of curvature of about 0.80 inches were
employed. As depicted in FIG. 2a, the radial center of the convex
face 18 is located along the center line of the gripper jaw tip
within the threaded stud 19. It is to be understood that the radial
center of the convex face 18 could be located along the center line
of the gripper jaw tip at any location, including beyond the
threaded stud 19 or beyond the cylindrical portion so long as a
convex face or spherical structure is produced.
[0056] FIG. 2b depicts the hexagon shape of base 17. According to
alternative embodiments, base 17 can be of any desired shape such
as square, rectangular, round, round with parallel flat sides, etc.
The base 17 is used to tighten the threaded stud 19 into a
corresponding threaded bore on the tips of a gripper jaw member.
Accordingly, the periphery of the base 17 should include surfaces
which can be easily gripped with a wrench or other tool for
tightening purposes.
[0057] FIGS. 3a and 3b are side and end views of a concave gripper
jaw tip according to one embodiment of the present disclosure. As
depicted, the gripper tip of FIG. 2a includes a base 20 which is
depicted as having a hexagonal shape, a cylindrical portion which
extends from base 20 and includes a concave face 21, and a threaded
stud 22 which extends from the base 20 on an opposite side from the
concave face 21. The concave face 21 has a partial spherical
concave shape that is complementary to the convex shape of the
gripper jaw tips of FIGS. 2a and 2b so that a workpiece can be
gripped therebetween. It is noted that the concave face 21 need not
form a spherical cavity to receive either a gripped tip with a
convex face or partial spherical shape.
[0058] FIG. 3b depicts the hexagon shape of base 20. According to
alternative embodiments, base 20 can be of any desired shape such
as square, rectangular, round, round with parallel flat sides, etc.
The base 20 is used to tighten the threaded stud 22 into a
corresponding threaded bore on the tips of a gripper jaw member.
Accordingly, the periphery of the base 20 should include surfaces
which can be easily gripped with a wrench or other tool for
tightening purposes.
[0059] In use, opposed jaws of a gripper assembly are provided with
one convex gripper tip as depicted in FIGS. 2a and 2b and a
matching convex gripper tip as depicted in FIGS. 3a and 3b.
[0060] FIG. 4 is a perspective view of a concave gripper jaw tip
which depicts how the tip is received in a gripper jaw. As
depicted, the threaded stud 22 of the concave gripper tip 23 is
received in a threaded bore 24 provided in jaw member 12. Although
the jaw member 12 in FIG. 4 is depicted as having a stepped tip
seat, it is to be understood that such a tip seat is not required
to receive the gripper tips of FIGS. 2-3. As discussed above, the
gripper tip 23 can be tightened into threaded bore 24 by use of a
wrench or other tool that is designed to engage base 20.
[0061] The convex and concave gripper tips of the present
disclosure have been found to eliminate or reduce the formation of
particulate that tend to flake or peel off workpieces at or near
the site they are gripped by the tips. Such flaking or peeling is
often attributed to the surface deformation of a workpiece. The
gripper tips of the present disclosure reduce or eliminate the
formation of particulates by avoiding sharp or abrupt edges where
gripping forces are applied to a workpiece.
[0062] FIG. 5 is a perspective view of angled gripper jaw tips
which depicts how the tips are received in a gripper jaw. The
gripper tips of FIG. 5 include recessed or stepped bases 25 which
are rectangular so as to be received and mate with a recessed or
stepped tip seat 26 formed on a jaw member 12. Once bases 25 of the
gripper tips 27 are received in the tip seat 26 of the jaw members
12, the overlapping edges which project from the recessed or
stepped portions restrict lateral motion between the gripper tips
27 and the tip seats 26.
[0063] The gripper tips 27 have workpiece gripping surfaces 28
which are formed at an acute angle with respect to their bases. The
workpiece gripping surfaces 28 can be provided with a diamond point
structure as depicted or any suitable surface structure, including
a smooth surface. In addition, the workpiece gripping surface can
be metal or formed of a polymeric or elastomeric material. The
gripping surfaces 28 can be provided any standard angles with
respect to the base of the gripper tip, including for example,
10.degree., 15.degree., 20.degree., 25.degree., 30.degree., . . .
55.degree., 60.degree., 65.degree., 70.degree., 75.degree., etc. or
at any angle in between.
[0064] The gripper tips 27 are provided with counter-sunk threaded
bores 29 which are provided to receive mechanical fasteners 30 that
can be used to secure the gripper tips 27 to the jaw members 12.
Alternatively, the mechanical fasteners could be inserted through
bores in the gripper tips and received in threaded bores in the jaw
members.
[0065] FIGS. 6a and 6b are side views of the gripper jaw tips of
FIG. 5 which depict alternative ways of aligning the gripper jaw
tips. As can be understood from FIGS. 6a and 6b, the recessed or
stepped portion 25 of the gripper tips 27 cooperate with the
recessed or stepped tip seat 26 in the jaw members so that the
angled gripper tips 27 are properly aligned. The recessed or
stepped portion 25 of the gripper tips 27 allow the gripper tips 27
to be attached to the jaw members 12 so that the angle at which
opposed gripper tips 27 meet is aligned as shown in either FIG. 6a
or 6b. It is to be understood that the structure of the recessed or
stepped portions could be designed, e.g., notched, so as to allow
the gripper tips 27 to be coupled to the tip seats 26 at four
positions instead of just the two positions depicted in FIGS. 6a
and 6b. Other engaging and position aligning structures could be
provided on the base of the gripper tips 27 and the tip seats 26.
For example, the gripper tips 27 could be cylindrical and the tip
seats 26 could have a cylindrical seat with cooperating aligning
structures on the bottom of the gripper tips 27 and the bottom of
the cylindrical seats 26. Alignment structures could be eliminated.
However, absent alignment structures, it would be necessary to
align opposed gripper tips 27 and thereafter secure them tightly to
the jaw members 12. It is also possible to provide gripper tips
that have compound gripping surface angles or even curved surfaces
that mate together.
[0066] FIG. 7 is an exploded view of a gripper tip assembly which
includes a workpiece sensor. The gripper tip assembly of FIG. 7
includes a bracket 31 that can be used to support a sensor 32
adjacent one of an opposed pair of gripper tips 33, 34. In the
embodiment depicted in FIG. 7 the sensor has an externally threaded
portion 35 which can be received in a through-hole 36 in bracket 31
and held in position by a pair of threaded nuts 37. As can be
understood, the position of the leading surface of the sensor 32
can be readily adjusted by loosening, positioning and retightening
the threaded nuts 37. The lead 38 of the sensor 32 can be coupled
to an audio or visual signaling device that will indicate the
presence or absence of a workpiece between the gripper tips 33,34.
Alternatively, the sensor 32 could be coupled to an automatic
counter or control device or system.
[0067] The bracket 31 can be coupled to one of the gripper tips 33
by a mechanical fastener 40 such as a threaded screw or bolt. In
order to maintain alignment of the bracket 31, two or more
mechanical fasteners could be used to secure the bracket 31 to the
gripper tip 33. Alternatively, the bracket 31 could be provided
with a structure which engages a corresponding structure on the
gripper tip 33 or a portion of the gripper jaw 12. For example, as
illustrated in FIG. 7, bracket 31 includes a projection 41 that
engages a groove 42 provided on the gripper tip 33. In other
embodiments, the sensor bracket 31 can be welded to gripper tip 33.
As depicted, gripper tip 33 can be secured to gripper jaw by a
mechanical fastener 30. It is noted that the embodiment of the
disclosure depicted in FIG. 7 and throughout, includes a jaw member
having a recessed or stepped tip seat and a gripper tip that has a
complimentarily recessed or stepped base. Using this similar
recessed or stepped structural configuration allows for
interchangeability of all the gripper tips with the jaw
members.
[0068] FIG. 8a is a side view of a gripper assembly having the
workpiece sensor of FIG. 7. FIG. 8b is a top view of a gripper
assembly having the workpiece sensor of FIG. 7. FIG. 8c is an end
view of a gripper assembly having the workpiece sensor of FIG. 7.
FIGS. 8a-8c depict how the tip assembly allows the leading edge of
the sensor 32 to be positioned adjacent the closed gripper tips
where it will sense the presence or absence of a workpiece. FIG. 8c
indicates how two sensor support brackets 31 can be used.
[0069] As discussed above, suitable sensors include mechanical
sensors, magnetic sensors, optical sensors, and sensors which
detect electrical properties. Mechanical sensors that are tripped
or otherwise moved when contacting a workpiece, and optical sensors
can be used in conjunction with metal and non-metal workpieces.
Magnet sensors and sensors that detect electrical properties such
as conductance can be used in conjunction workpieces that are made
from metal, magnetizable materials, and electrically conductive
materials.
[0070] According to another embodiment of the present disclosure
which is depicted in FIG. 9 a sensor can be fitted in the face of a
gripper tip. FIG. 9 is a perspective view of a gripper tip which
has been notched out and configured to receive a sensor in the face
thereof. This gripper tip 50 is similar to gripper tip 33 depicted
in FIG. 7, but has been notched out and provided with a wider
portion which serves as a base 51 upon which a flat sensor can be
mounted between the adjacent workpiece gripping surfaces 52. The
sensor can be secured in place by mechanical fasteners or clips.
Leads for the sensor can either pass through a hole(s) provided in
base 51 or from an end of the sensor. The gripper tip 50 can
include a threaded bore 53 by which it can be secured to a gripper
jaw. In this case, a threaded fastener can be inserted though the
back of a gripper jaw and received in the threaded bore 53 of the
gripper tip.
[0071] FIG. 10 is an exploded view of a gripper jaw tip assembly
which includes a tip extender that can be used to extend the
working length of gripper tips. The gripper jaw tip assembly of
FIG. 10 includes a tip extender 60 that can be coupled to the tip
seat 61 of jaw member 62 by a suitable means such as mechanical
fastener 63. The tip extender 60 includes a base portion 64 and an
arm member 65. Although not shown, the base portion 64 can include
a cut-out structure (in the bottom as depicted in FIG. 10) which is
shaped complimentarily to the tip seat 61. The inclusion of such a
cut-out or shaped portion will ensure that the arm member 65 of the
tip extender 60 of FIG. 10 will be easily aligned with the jaw
member 62 when coupled thereto. The tip extender 60 of FIG. 10 can
be aligned so that the axis of the arm member 65 is parallel to the
axis of the jaw member 62. Alternatively, the tip extender 60 of
FIG. 10 can be designed so that the arm member 65 of the tip
extender 60 extends from the jaw member 62 at any desired angle. In
other embodiments a curved or angled arm member can be used.
[0072] The arm member 65 of tip extender 60 includes at least one
through-bore 66, which can be used to couple various jaw tips
thereto. The through-bore(s) 66 can have internal threads into
which jaw tips can be threaded or into which a threaded fastener 67
can be used to couple a jaw tip to the arm member 65 of the tip
extender 60. Alternatively, the through-bore(s) 66 can be
non-threaded and a threaded fastener 67 can be used to couple a jaw
tip to the arm member 65 of the tip extender 60.
[0073] FIG. 10 depicts examples of various jaw tips 68-73 which can
be coupled to and used in conjunction with the tip extender 60.
These include a single cone gripper tip 68, a single padded gripper
tip 69, a double padded gripper tip 70, a single diamond point pad
gripper tip 71, a double diamond point pad gripper tip 72, and a
double cone gripper tip 73.
[0074] FIG. 11 is an exploded view of a gripper jaw tip assembly
which includes a tip extender that can be used to extend the
working width of gripper tips. The gripper jaw tip assembly of FIG.
11 includes a tip extender 80 that can be coupled to the tip seat
81 of jaw member 82 by a suitable means such as mechanical fastener
83. The tip extender 80 includes a base portion 84 and a pair of
arm members 85. Although not shown, the base portion 84 can include
a cut-out structure (in the bottom as depicted in FIG. 11) which is
complementary to the tip seat 81. The inclusion of such a cut-out
or shaped portion will ensure that the arm members 85 of the tip
extender 80 of FIG. 11 will be easily aligned to be perpendicular
with the jaw member 82 when coupled thereto. The tip extender 80 of
FIG. 11 is depicted as being aligned so that the arm members 85 are
perpendicular to the axis of the jaw member 82. Alternatively, the
arm members 85 of the tip extender 80 of FIG. 11 can be aligned
with the jaw member 82 at any suitable angle. In other embodiments
two or more straight, and/or curved and/or angled arm members can
be used.
[0075] The arm members 85 of tip extender 80 each includes at least
one though-bore 86, which can be used to couple various jaw tips
thereto. The through-bore(s) 86 can have internal threads into
which jaw tips can be threaded or into which a threaded fastener 87
can be used to couple a jaw tip to the arm members 85 of the tip
extender 80. Alternatively, the through-bore(s) 86 can be
non-threaded and a threaded fastener 87 can be used to couple a jaw
tip to the arm members 85 of the tip extender 80.
[0076] FIG. 11 depicts examples of various jaw tips 88-93 which can
be coupled to and used in conjunction with the tip extender 80.
These include a single cone gripper tip 88, a single padded gripper
tip 89, a double padded gripper tip 90, a single diamond point pad
gripper tip 91, a double diamond point pad gripper tip 92, and a
double cone gripper tip 93.
[0077] FIG. 12a is a cross-sectional side view of a padded gripper
tip having fluid expelling channels. The padded gripper tip of
FIGS. 12a-12c includes a base 100 which can be made of metal and a
pad portion 101 which can be made from a rubber material, polymeric
material, plastic material or other suitably resilient material.
The base 100 includes an internally threaded bore 102 which extends
within a projection 103 of the base 100. As depicted, the
internally threaded bore 102 can terminate at a bottom that is
within the projection 103. The pad portion 101 is secured, e.g.,
molded over or otherwise bonded on the projection 103.
[0078] FIG. 12b is an end view of the padded gripper tip of FIG.
12a. As depicted in FIG. 12b the face 104 of the pad portion 101
includes a central recessed portion 105 and a plurality of channels
106 which are radially disposed with respect to the central
recessed portion 105. As depicted in FIG. 12a, the central recessed
portion 105 can have a depth which is greater than the depth of
channels 106.
[0079] FIG. 12c is a side view of the padded gripper tip of FIG.
12a. As illustratively depicted in FIG. 12c, the channels can have
U-shaped bottoms.
[0080] When the face of the padded gripper tip of FIGS. 12a-12c is
pressed against a portion of a workpiece that has a liquid coating
thereon, the liquid that might otherwise be trapped between the
face 104 of the pad portion 101 of the tip and the workpiece
surface is squeezed into the channels 106 and central recessed
portion 105. Excess fluid is expelled outward through the channels
106 as the pad portion 101 of the gripper tip is compressed against
the surface of the workpiece.
[0081] It is to be understood that the present disclosure is not
limited to the pattern formed by the central recess portion 105 and
channels 106 which is depicted in FIGS. 12a-12c. Other patterns
which do not include channels that are blocked from communicating
with the sides of the pad portion 101 can also be used.
[0082] The padded gripper tip of FIGS. 12a-12c can be attached to
the tip seat of a jaw member of a gripper by use of a threaded
fastener which can be passed through the tip seat of the jaw member
and received in the internally threaded bore 102. Alternatively,
the padded gripper tip could include a threaded projection in place
of the internally threaded bore, and the threaded projection could
be driven into an internally threaded bore provided on the tip seat
of a jaw member.
[0083] FIG. 13a is a cross-sectional side view of another padded
gripper tip having fluid expelling channels. The padded gripper tip
of FIGS. 13a-13c includes a rectangular base 110 which can be made
of metal and a pair of pad portions 111 which can be made from a
rubber material, a polymeric material, a plastic material or other
suitably resilient material. The base 110 includes an internally
threaded bore 112 which extends therethrough. The base 110 includes
a pair of through-bores 113 adjacent either end into which the pad
portions 111 can be molded.
[0084] FIG. 13b is an end view of the padded gripper tip of FIG.
13a. As illustratively depicted in FIG. 13b the face 114 of each
pad portion 111 includes a plurality of channels 115 which can be
arranged in an array or grid pattern.
[0085] FIG. 13c is a side view of the padded gripper tip of FIG.
13a. As depicted in FIGS. 13a and 13c, the channels 115 can have
U-shaped bottoms.
[0086] It is to be understood that the present disclosure is not
limited to the pattern formed by the channels 115 which is depicted
in FIGS. 13a-13c. Other patterns which do not include channels that
are blocked from communicating with the sides of the pad portions
111 can also be used.
[0087] The padded gripper tip of FIGS. 13a-13c can be attached to
the tip seat of a jaw member of a gripper by use of a threaded
fastener which can be passed through the tip seat of the jaw member
and received in the internally threaded bore 112. Alternatively,
the padded gripper tip could include a threaded projection in place
of the internally threaded bore, and the threaded projection could
be driven into an internally threaded bore provided on the tip seat
of a jaw member, or a through-hole.
[0088] Although the present disclosure has been described with
reference to particular means, materials and embodiments, from the
foregoing description, one skilled in the art can easily ascertain
the essential characteristics of the present disclosure and various
changes and modifications may be made to adapt the various uses and
characteristics without departing from the spirit and scope of the
present disclosure as described by the claims which follow.
* * * * *