WELDING MACHINE

• US 3,860,782 A
• Filed: 08/12/1971
• Issued: 01/14/1975
• Est. Priority Date: 08/12/1971
• Status: Expired due to Term

• Current Assignee: Bill Lee Hamby
• Original Assignee: Bill Lee Hamby
• Inventors: Hamby, Bill Lee
• Primary Examiner(s): Albritton, C. L.
• Application Number:
  US05/171,095
• Time in Patent Office: 1,251 Days
• Field of Search: 219/86,89,78,91
• US Class Current: 219/89
• CPC Class Codes: B23K 11/0026 Welding of thin articles
• CPC Class Codes: B23K 11/163 Welding of coated materials
• CPC Class Codes: H01R 43/02 for soldered or welded connections

Abstract

A pneumatically operated welding machine particularly useful for welding small diameter wires onto pins for electronic circuitry is described. In such welding an insulated wire is fed through a hollow upper electrode for welding between the electrode and a pin. Equal pressures applied by the upper and lower electrodes first exert sufficient force for penetrating the plastic insulation and thereafter the force is reduced to an optimum level for welding. The upper and lower electrodes are connected to double acting pneumatic cylinders connected to a pneumatic circuit that sequentially brings the electrodes into light contact with the workpiece for lateral positioning, applies sufficient breakthrough force to penetrate the plastic insulation, applies a reduced force during a welding period and finally retracts the electrodes. Such light weight, low inertia, low friction, pneumatic electrode actuation provides balanced force between the electrodes and sufficient compliance that excellent welds are uniformly obtained irrespective of pin length or position.

Claims

1. A pneumatic welder for welding a conductor through a cold flowable insulation comprising:

a pair of opposed electrodes;

a pneumatic actuator connected to one of the electrodes for imparting movement thereto towards the other electrode;

manifold means for connection to a source of pressurized gas;

position pressure means connected to the manifold means for sUpplying the gas to the actuator under a first predetermined sufficient pressure to contact the electrode attached thereto with an insulated conductor to be welded without penetrating the insulation;

breakthrough pressure means connected to the manifold means for supplying the gas to the actuator under a second predetermined sufficient pressure to press the electrode attached thereto through the insulation around the conductor sequentially after the positioning pressure means;

weld cycle pressure means connected to the manifold means for supplying the gas to the actuator under a third predetermined sufficient pressure to maintain a desired welding force sequentially after the breakthrough pressure means; and

release means coupled to the one electrode for moving the electrodes apart.

2. A pneumatic welder as defined in claim 1 wherein the release means comprises pressure means connected to the manifold means for supplying the gas to the actuator under a predetermined sufficient pressure for moving the electrodes apart.

3. Pneumatic apparatus for welding a conductor through cold flowable insulation surrounding the conductor to a desired workpiece comprising:

a. a pair of electrodes for engaging the conductor and the workpiece respectively, b. means for engaging the electrodes in separate contact with the workpiece and the conductor and including a pneumatic actuator connected to at least the conductor electrode for imparting desired movement to the conductor electrode, the actuator comprising;

i. position pressure means coupled to the pneumatic actuator for supplying gas to the actuator under sufficient pressure to move the conductor electrode into engagement with an insulated conductor to be welded and to move the conductor into engagement with the workpiece, ii. breakthrough pressure means coupled to the pneumatic actuator for supplying gas to the actuator under a sufficient pressure to press the conductor electrode through the insulation into contact with the conductor and to press the conductor through the insulation into contact with the workpiece sequentially after operation of the position pressure means, and iii. weld cycle pressure means coupled to the pneumatic actuator for supplying gas to the actuator under a sufficient pressure to maintain a desired welding force between the conductor and the workpiece sequentially after operation of the breakthrough pressure means; and

c. release means coupled to at least the conductor electrode for disengaging the electrodes from the conductor and the workpiece.

4. A pneumatic welder for welding a conductor through a cold flowable insulation comprising:

a pair of opposed electrodes;

a first pneumatic actuator connected to one of the electrodes for imparting movement thereto towards the other electrode;

a second pneumatic actuator connected to the other electrode for imparting movement thereto towards the one electrode;

manifold means for connection to a source of pressurized gas;

position pressure means connected to the manifold means for supplying gas to both actuators under first predetermined sufficient pressure to contact the one electrode with an insulated conductor to be welded;

breakthrough pressure means connected to the manifold means for supplying gas to both actuators under a second predetermined sufficient pressure to press the one electrode through the insulation around the conductor sequentially after the positioning pressure means;

weld cycle pressure means connected to the manifold means for supplying gas to both actuators under a third predetermined sufficient pressure to maintain a desired welding force sequentially after the breakthrough pressure means; and

release means coupled to the one electrode for moving the electrodes apart.

5. A pneumatic welder as defined in claim 4 wherein each actuator comprises:

a cylinder;

end caps on each end of the cylinder;

a slidably movable piston rod Extending through the two end caps;

a piston fixed on the piston rod in the cylinder for dividing the interior thereof into two chambers;

means on an end of the piston rod for attaching an electrode thereto; and

a flexible electrical lead having an end connected to the piston rod, and wherein the combined weight of the piston, piston rod, electrode and lead is very small relative to the force exerted on the electrode by the breakthrough pressure means.

6. A pneumatic welder as defined in claim 5 wherein one of the piston rods and one of the electrodes are hollow for passing an insulated conductor wire therethrough.