Resistance spot welding gun and transformer assembly

Claim 2

A resistance welding apparatus for forming a weld on a work piece, said apparatus comprising: a transformer having a pair of output terminals; a cylinder and piston assembly shiftable axially relative to one another along a cylinder axis and including a piston rod attached to the piston and extending axially from at least one end of the cylinder and piston assembly; a pair of electrodes, one of the electrodes being connected to the cylinder and the other electrode being connected to the piston rod; flexible connector means for electrically connecting said electrodes to the transformer output terminals; and bracket means for slidably attaching the cylinder and piston assembly to the transformer to allow limited movement therebetween along an axis substantially parallel to the cylinder axis and enabling the electrodes to maintain a self-equalizing pressure on the work piece.

Claim 3

The invention of claim 1 further comprising spring means for elastically connecting the cylinder to the transformer for adjusting the relative pressure exerted by the electrodes on the work piece.

Claim 4

The invention of claim 1 further comprising a first jaw member attaching the cylinder to the electrode connected thereto, orientating the two electrodes in opposed aligned manner and providing clearance to allow the insertion of the work piece therebetween.

Claim 5

The invention of claim 3 further comprising means for coupling the cylinder and piston assembly to a source of fluid to cause the cylinder and piston and their respective electrodes to move realtive to one another between an open position where the electrodes are separated, and a closed position where the electrodes engage a work piece therebetween.,

Claim 6

The invention of claim 4 further comprising a second jaw member connecting the piston rod to the electrode attached thereto.

Claim 7

The invention of claim 5 wherein first and second jaws are provided with means for passing a coolant therethrough to maintain the electrodes at a desired operating temperature.

Claim 8

The invention of claim 4 further comprising sensor means for detecting the failure of the electrodes to return to their fully open position.

Claim 9

The invention of claim 4 wherein said flexible connection means further comprises a U-shaped rolling shunt.

Claim 10

The invention of claim 3 wherein said first jaw member is further provided with means for removable attachment to the cylinder thereby enabling first jaw members having different configurations to be interchangeably substituted.

Claim 11

A resisting welding apparatus adapted to be mounted on a robot arm actuator to form spot welds on a work piece, said apparatus comprising: a frame; a transformer attached to said frame and having a pair of output terminals; a cylinder and piston assembly shiftable axially relative to one another along a cylinder axis and including a piston rod attached to the piston and extending axially from at least one end of the cylinder and piston assembly; a pair of electrodes, one of the electrodes being connected to the cylinder and the other electrode being connected to the piston rod; flexible connector means for electrically connecting said electrodes to the transformer output terminals; and guide means for slidably attaching the cylinder and piston assembly to the frame to permit limited movement therebetween along an axis substantially parallel to the cylinder axis allowing a pair of electrodes to self-position about the work piece during welding.

Claim 12

A resisting welding apparatus adapted to be mounted on a robot arm actuator to form spot welds on a work piece, said apparatus comprising: a frame; a transformer attached to said frame and having a pair of output terminals; a cylinder and piston assembly shiftable axially relative to one another along a cylinder axis and including a piston rod attached to the piston and extending axially from at least one end of the cylinder and piston assembly; a pair of electrodes, one of the electrodes being connected to the cylinder and the other electrode being connected to the piston rod; flexible connector means for electrically connecting said electrodes to the transformer output terminals; and guide means for slidably attaching the cylinder and piston assembly to the frame to permit limited movement therebetween along an axis substantially parallel to the cylinder axis allowing a pair of electrodes to self-position about the work piece during welding.

Claim 13

The invention of claim 10 further comprising a first jaw member attaching the cylinder to the electrode connected thereto, orientating the two electrodes in opposed aligned manner and providing clearance to allow the insertion of the work piece therebetween.

Claim 14

The invention of claim 11 wherein said flexible connection means further comprises a U-shaped rolling shunt.

Claim 15

The invention of claim 11 further comprising sensor means for detecting the failure of the electrodes to return to their fully open position.

Claim 16

The invention of claim 11 further comprising a second jaw member connecting the piston rod to the electrode attached thereto.

Claim 17

The invention of claim 14 wherein first and second jaws are provided with means for passing a coolant therethrough to maintain the electrodes at a desired operating temperature.

Claim 18

The invention of claim 11 wherein said first jaw member is further provided with means for removable attachment to the cylinder thereby enabling first jaw members having different configurations to be interchangeably substituted.

Claim 19

The invention of claim 11 further comprising spring means for elastically connecting the cylinder to the transformer for adjusting the relative pressure exerted by the electrode on the work piece.

Claim 20

The invention of claim 11 further comprising means for coupling the cylinder and piston assembly to a source of fluid to cause the cylinder and piston and their respective electrodes to move relative to one another between an open position where the electrodes are separated, and a closed position where the electrodes engage a work piece therebetween.

Claim 21

The invention of claim 18 wherein said electrodes are co-axially aligned with the cylinder axis.