The invention provides a gripper for a tack welding gun wherein the tack gripper is u-shaped in design. The tack gripper has two arms connected by a base. At least one arm of the tack gripper is resilient in design. The arms have a bent back portion at their free end. The portion is arranged between the respective arms. The portions contain holes in which the catch knobs formed on the workpiece to be welded can engage.

PTO Wrapper PDF
Dossier Espace Google
Patent
   RE37735
Priority
May 26 1995
Filed
Oct 18 2000
Issued
Jun 11 2002
Expiry
May 23 2016
Inventors
Roser, Her…
Assg.orig
Emhart LLC
Assg.curr
Newfrey LLC
Entity
Large
Referenced by
0
References
8
Maint.:
all paid
DESCRIPTION OF THE P…
1. A tack gripper for a tack welding gun, characterized in that the tack gripper (1) is designed in the form of a u with two arms (2, 3) connected via a base (4), at least one free arm (2, 3) of the tack gripper (1) being resilient.
0. 24. A gripper for holding a workpiece in a welding gun for presentation to and attachment by welding on a body, said gripper comprising:
a mounting base (4) adapted for connection to a welding gun;
a pair of metal arms (2, 3) attached to opposing sides of said base and extending from said element in spaced relationship;
the free ends of said arms being bent in a u-shape and extending back toward said base; and
at least one of said arms being resilient to enable said arms to receive and frictionally retain a workpiece between said arms.
2. A tack gripper according to claim 1, characterized in that at least one said arm (2, 3) has at least one hole (5, 6, 7) in a region (12) adjacent to its free end.
3. A tack gripper according to claim 2, characterized in that a plurality of holes (5, 6, 7) are provided, said holes being aligned transversely to the length of the arm (2, 3).
4. A tack gripper according to claim 3, characterized in that at least one said arm (2, 3) has, at its free end, a portion (8, 9) which is bent over itself, said portion (8, 9) being arranged between the arms (2, 3) and said holes (5, 6, 7) optionally being formed in the portion (8, 9).
5. A tack gripper according to claim 1, characterized in that each said arm (2, 3) is detachably connected to said base (4).
6. A tack gripper according to claim 2, characterized in that at least one arm (2, 3) can be spread against an additional spring force.
7. A tack gripper according to claim 6, characterized in that at least one spring element (10, 11) is arranged on at least one said arm (2, 3).
8. A tack gripper according to claim 7, characterized in that said spring element (10, 11) is a spring subjected to bending, the spring element (10, 11) being secured on one side in a region of said arm (2, 3) in which said arm (2, 3) at least partially overlaps said base (4).
9. A tack gripper according to claim 8, characterized in that said spring element (10, 11) is a leaf spring.
10. A tack gripper according to claim 8, characterized in that said spring element (10, 11) is curved in the form of an arc toward the arm (2, 3) at least at its free end.
11. A tack gripper according to claim 10, characterized in that said base (4) is formed by a cuboid carrier (13).
12. A tack gripper according to claim 11, characterized in that said arms (2, 3) and said spring element (10, 11) are screwed to said carrier (13).
13. A tack gripper according to claim 12, characterized in that each arm (2, 3) has a groove (14, 15), a pair of respective projections (16, 17) being formed on said carrier (13), said projections being engageable in said grooves.
14. A tack gripper according to claim 13, characterized in that said base (4) and said arms (2, 3) consist of bronze.
15. A tack gripper according to claim 13, characterized in that said arms (2, 3) are identical in design.
16. A tack gripper according to claim 13, characterized in that at least one of said base (4) and said arms (2, 3) have at least one cooling fin disposed thereon.
17. A tack gripper according to claim 13, characterized in that the base (4) has at least one cooling duct (31) which is connected to a coolant supply system.
18. A tack gripper according to claim 17, characterized in that said duct (31) is connected to the coolant supply system via a feed conduit and a discharge conduit.
19. A tack gripper according to claim 17, characterized in that the coolant is protective gas, water and/or air.
20. A workpiece which can be tack welded by means of a tack welding gun with a tack gripper according to claim 15 to a component having at least a pair of gripping surfaces grippable by a tack gripper (1), wherein at least one of said gripping surfaces (21, 22) is formed with at least one catch knob (18, 19); at least one of said arms (2, 3) is provided with at least one hole (5, 6, 7); said catch knob being adapted to engage in said hole.
21. A workpiece according to claim 20, characterized in that said catch knobs (18, 19) are formed by embossment.
22. A workpiece according to claim 20, characterized in that said catch knobs (18, 19) have a height of 0.3 to 0.5 mm.
23. Process for connecting a strip-form workpiece (20) to a component in which a tack gripper (1) of a tack welding gun according to claim 1, grips and frictionally secures a portion @of a metallic strip-form workpiece band, a separating device severs a strip of predetermined length from the band to form the workpiece (20), the tack gripper (1) initially positions the workpiece (20) on the component and then welds it thereto and the tack gripper (1) is then removed from the workpiece (20).
0. 25. Process for connecting a strip-form workpiece (20) to a component in which a gripper (1) of a welding gun according to claim 24, grips and frictionally secures a portion of a metallic band, a separating device severs a strip of predetermined length from the band to form the workpiece (20), the gripper (1) initially positions the workpiece (20) on the component and then welds it thereto and the gripper (1) is then removed from the workpiece (20).
0. 26. A gripper according to claim 24, characterized in that at least one said arm (2, 3) has at least one hole (5, 6, 7) in a region (12) adjacent to its free end.
0. 27. A gripper according to claim 26, characterized in that a plurality of holes (5, 6, 7) are provided, said holes being aligned transversely to the length of the arm (2, 3).
0. 28. A gripper according to claim 27, characterized in that at least one said arm (2, 3) has, at its free end, a portion (8, 9) which is bent over itself, said portion (8, 9) being arranged between the arms (2, 3) and said holes (5, 6, 7) being formed in the portion (8, 9).
0. 29. A gripper according to claim 24, characterized in that said arm (2, 3) is detachably connected to said base (4).
0. 30. A gripper according to claim 25, characterized in that at least one arm (2, 3) can be spread against an additional spring force.
0. 31. A gripper according to claim 29, characterized in that at least one spring element (10, 11) is arranged on at least one said arm (2, 3).
0. 32. A gripper according to claim 31, characterized in that said spring element (10, 11) is a spring subjected to bending, the spring element (10, 11) being secured on one side in a region of said arm (2, 3) in which said arm (2, 3) at least partially overlaps said base (4).
0. 33. A gripper according to claim 32, characterized in that said spring element (10, 11) is a leaf spring.
0. 34. A gripper according to claim 32, characterized in that said spring element (10, 11) is curved in the form of an arc toward the arm (2, 3) at least at its free end.
0. 35. A gripper according to claim 34, characterized in that said base (4) is formed by a cuboid carrier (13).
0. 36. A gripper according to claim 35, characterized in that said arms (2, 3) and said spring element (10, 11) are screwed to said carrier (13).
0. 37. A gripper according to claim 36, characterized in that each said arm (2, 3) has a groove (14, 15), a pair of respective projections (16, 17) being formed in said grooves (13), said projections being engageable in said grooves.
0. 38. A gripper according to claim 37, characterized in that said base (4) and said arms (2, 3) consist of bronze.
0. 39. A gripper according to claim 37, characterized in that said arms (2, 3) are identical in design.
0. 40. A workpiece adapted to be held by a gripper according to claim 34, said workpiece having at least a pair of gripping surfaces; at least one of said gripping surfaces (21, 22) being formed with at least one catch knob (18, 19); at least one of said arms (2, 3) being provided with at least one hole (5, 6, 7); said catch knob being adapted to engage in said hole.
0. 41. A workpiece according to claim 40, characterized in that said catch knobs (18, 19) are formed by embossment.
0. 42. A workpiece according to claim 40, characterized in that said catch knobs (18, 19) have a height of 0.3 to 0.5 mm.
0. 43. A gripper according to claim 37, characterized in that at least one of said base (4) and said arms (2, 3) have at least one cooling fin disposed thereon.
0. 44. A gripper according to claim 37, characterized in that the base (4) has at least one cooling duct (31) which is connected to a coolant supply system.
0. 45. A gripper according to claim 44, characterized in that said duct (31) is connected to the coolant supply system via a feed conduit and a discharge conduit.
0. 46. A gripper according to claim 44, characterized in that the coolant is protective gas, water and/or air.

The invention relates to a tack

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows an embodiment of a tack gripper 1 which is U-shaped in design. The tack gripper comprises a base 4 to which two arms 2, 3 are connected. The base 4 is formed by a cuboid carrier 13. Bores (not shown) through which screws 23 extend are formed in the carrier 13. The screws 13 23 are screwed to nuts 30.

24 designates a receiving bore 24 which is formed in the carrier 13 and serves to connect the tack gripper 1 to the welding head of a tack welding gun and to the welding current supply. The carrier 13 has cooling ducts 31 through which a coolant such as water can be conveyed. Connecting lines which connect a coolant supply system to the cooling ducts 31 are not shown. The carrier 13 and/or the arms 2, 3 can be provided with cooling fins in addition to cooling ducts 31 or instead of them. The term cooling fins includes plane fins and rod-shaped fins. If plane fins are formed on the arms 2, 3, they preferably extend transversely to the length of the arms 2, 3 to prevent the resilience of the arms 2, 3 being eliminated by plane fins.

Each arm 2, 3 is resilient in design and, as well as the base 4, can be composed of a suitable low electrical resistance material such as, for example, bronze. The arms 2, 3 are identical in design. Each arm 2, 3 has holes 5, 6, 7 in a region 12 adjacent to its free end. The holes 5, 6, 7 are aligned transversely to the length of the arm 2, 3. The arm 2, 3 has, at its free end, a portion 8 or 9 which is bent over itself. The portion 8 or 9 is arranged between the arms. As shown in FIG. 2, the holes 5, 6 and 7 are formed in the bent over portion 8 or 9.

The two arms 2, 3 can be spread against an additional spring force in each case. A spring element 10 or 11, such as a leaf spring, is arranged on the arm 2 or 3. This spring element 10, 11 is a spring subjected to bending stress. The spring element 10, 11 is fixed at one end in a region of the arm 2, 3 by the screw connection 23.

The spring element 10 or 11 has three resilient tongues 25, 26 and 27 which are formed at a distance from one another. Each spring tongue 25, 26 and 27 is curved in the form of an arc to the arm 2 or 3 in its front region.

Each arm 2, 3 has a groove 14, 15 in which a respective projection 16 or 17 formed on the carrier 13 engages. To fix the arm 2 or 3 on the carrier 13, the arm 2 or 3 has orifices 28, 29 through which a screw 23 penetrates. Corresponding apertures (not shown) are formed on the respective spring element 10 or 11.

FIG. 3 shows a workpiece 20. The workpiece 20 is a strip-form part. The workpiece 20 has a pair of gripping surfaces 21, 22 which can be gripped by a tack gripper 1. Catch knobs 18 are formed on the gripping surface 21. A catch knob 19 is formed on the gripping surface 22. The knobs 18, 19 lie on an imaginary straight connecting line. The design of the knobs 18, 19 creates three-point contact which provides a defined location for the workpiece 13 20 in the tack gripper. The catch knobs 18 or 19 are arranged in such a way that the catch knobs engage in the holes 5, 6, 7 of the arm 2 or 3.

In a process for connecting the strip-form workpiece 20 to a component, the gripper 1, associated with the welding gun, grips and frictionally secures a portion of a metallic band. A separating device severs a strip of predetermined length from the band to form the workpiece 20. The gripper 1 initially positions the workpiece 20 on the component and then welds the workpiece to the component. The gripper 1 is then removed from the workpiece 20.

It is noted that the gripper 1 can be a tack gripper, and the welding gun can be a tack welding gun, all without departing from the spirit and scope of the invention.

INVENTORS:

Roser, Hermann

THIS PATENT IS REFERENCED BY THESE PATENTS:
Patent Priority Assignee Title
THIS PATENT REFERENCES THESE PATENTS:
Patent Priority Assignee Title
1748346,
2376957,
3678241,
3729125,
4771160, Jul 08 1986 Lothar Schmitt GmbH Welding tongs
6025569, Sep 03 1998 Senco Products, Inc. Magazine and a stud advancing system for use with a manual stud welding tool
JP57115984,
LU58692,
ASSIGNMENT RECORDS    Assignment records on the USPTO
//
Executed onAssignorAssigneeConveyanceFrameReelDoc
Oct 18 2000Emhart LLC(assignment on the face of the patent)
Oct 30 2002Emhart LLCNewfrey LLCCHANGE OF NAME SEE DOCUMENT FOR DETAILS 0135160757 pdf
MAINTENANCE FEES AND DATES:    Maintenance records on the USPTO
Date Maintenance Fee Events
Jul 01 2002M183: Payment of Maintenance Fee, 4th Year, Large Entity.
Jul 07 2006M1552: Payment of Maintenance Fee, 8th Year, Large Entity.
Aug 09 2010M1553: Payment of Maintenance Fee, 12th Year, Large Entity.


Date Maintenance Schedule
Jun 11 20054 years fee payment window open
Dec 11 20056 months grace period start (w surcharge)
Jun 11 2006patent expiry (for year 4)
Jun 11 20082 years to revive unintentionally abandoned end. (for year 4)
Jun 11 20098 years fee payment window open
Dec 11 20096 months grace period start (w surcharge)
Jun 11 2010patent expiry (for year 8)
Jun 11 20122 years to revive unintentionally abandoned end. (for year 8)
Jun 11 201312 years fee payment window open
Dec 11 20136 months grace period start (w surcharge)
Jun 11 2014patent expiry (for year 12)
Jun 11 20162 years to revive unintentionally abandoned end. (for year 12)