AU655737B1 - Push-pull separate wire feeder - Google Patents

Description

P/00/0 1 1 281"19 Regulation 3.2

AUSTRALIA

Patents Act 1990 655737

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention *,.The following statement is a full description of this invention, including the best method of performing it known to me:-- 0. .t 14

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ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention title: PUSH -PULL SEPARATE WIRE FEEDER (FOR MIG WELDERS) Application No: PM-4079 The following statement is a full description of thi.s invention, including the best method of performing it known to me: S This invention demonstrates the flexibility and simplicity of converting an existing MIG welding machine to a totally portable and lightweight remote unit.

MIG welder operators require the need to extend the operation of their welders to a much smaller unit, preventing the inconvenience of moving these heavy machines around.

a A typical existing SEPARATE WIRE FEEDER is a unit which is connected to a MIG o welder to provide this versatility. It comprises of an adjustable WIRE FEED MOTOR with a e *9 PRINTED CIRCUIT BOARD to control the motor speed, and a BRASS TORCH ADAPTOR socket to connect the MIG WELDING TORCH.

These units house a 15 kg spool of welding wire, which is fed to the operators welding torch.

They are supplied with an EIGHT METER INTER-CONNECTION LEAD to link the S.W.F. to S 15 the MIG welder. Various makes and models that are available, operate by placing this spool of welding wire inside them. This design makes these feeders large, heavy and awkward to handle, Many MIG welding machines that are specificai ~p~nufactured with these S.W.F.s' are designed to operate dependently. (These models are the MIG-S.W.F. type). The welder only S 20 incorporates the POWER SOURCE that is required to generaoa the output power needed to Smelt the welding wire, From this power source, tle interconnecting lead transfers this power to the S.W.F. The S.W.F. containing the 15kg spool of welding wire is then fed to the operators welding torch (connected to the brass torch connector socket), from the drive motor-roller assembly.

The disadvantage is that the MIG welder and S.W.F cannot be seperated or used Individually. These S.W.F.s' are too bulky and the interconnection cable is un-protected.

d 4?,P _j Another MIG welder available is the COMPACT type. These welders contain the WELDING WIRE, FEED MOTOR, associated SPEED CONTROL CIRCUIT BOARD, BRASS TORCH ADAPTOR SOCKET, and POWER SOURCE in the one machine.

A major disadvantage with these type of MIG welders, is that operators require a need for an S.W.F. to be connected to them to improve maneuverability and flexibility of these MIG welders. This results in excessive alteration to the MIG welder. The wire feed motor-roller assembly, brass torch adaptor socket, P.C.B and spool of wire are then removed and transfered to the S.W.F. After these alterations are carried out, the MIG welder and the installed S.W.F. cannot be detached, resulting in reliance and dependability of these 1o combined units for operation.

All these problems are overcome by the present invention.

a. 000 A series of drawings of the proto-type are displayed from Figures 1 to 5, giving a visual .OO. understanding of connection, application, and operation of the invention.

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i I -3- CONNECTION OF THE P.P.S.W.F.

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4 £r 9t 9 The interconnecting lead (FIG 1-1) has a plug-in brass torch adaptor (FIG 1-2) which is similar to that of the welding torch. This fitting connects directly to the MIG welder output socket (shown in FIG 3A-1), in place of the welding torch .This fitting supplies the PUSH- PULL SEPARATE WIRE FEEDER the required welding wire, gas, power and control cables.

A brass insulated NEGATIVE or EARTH plug (FIG 1-3) is also connected to the welder, (FIG 3A-2) replacing the existing EARTH lead. These two connections supply power to the

P.P.S.W.F.

The only modification required is to connect the supplied three wire socket (FIG 1-4) to the MIG welders' P.C.B.This simple three wire clip-in connection electrically links both PUSH motor (from welder) and PULL motor (in the and diverts speed control to the P.P.S.W.F.(Both PUSH and PULL motors are similar and incorporate a gearbox and drive roller assembly).When connected, this socket is then permanently fitted to the front panel of the MIG welder.

IS FIG 2. displays a schematic diagram of the motor speed control P.C.B. of the PUSH-PULL SEPARATE WIRE FEEDER.

The circuit is powered by the 18-48VDC output welding voltage of the MIG welder, via the 35mm positive and negative power cables.

The circuit consists of a simple astable multivibrator oscillating circuit using a 555 timer, 20 regulated to a 12VDC supply voltage via the 470ohm resistor and 12V zener diode and protected by a 5A fuse.The external capacitors provide the required output frequency of the timer and varied by the 10Kohm potentiometer via the 100ohm resistors.The variable output frequenocy of the oscillator is amplified and interfaced to M1 and M2 through a POWER MOSFET to achieve speed/current control of these motors.

25 When plug (FIG 1-5) is inserted into the pre-installed socket (FIG the internal switch in this socket closes to divert the 24VDC supply of the welder motor to the relay coil in the P.C.B.This switch also connects the PUSH and PULL motors in parallel to achieve synchronous speed and equal load distribution amongst these motors.

When the trigger switch of the welding torch is depressed, the output welding voltage is applied to power the oscillating circuit (through the 12V regulator), and the original 24VDC supply of M1 (welder motor) energises the relay coil.The NORMALLY OPEN contact then closes allowing both Ml and M2 to connect directly to the output of the POWER MOSFET to commence rotation and feeding.

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When the trigger switch opens, the relay coil de-energises reverting the contact to the NORMALLY CLOSED position whereby a short-circuit is applied to the motors to provide instant braking and stop the wire feeding process.

(FIG 3A) shows a typical COMPACT MIG WELDER with torch removed from the brass torch socket adaptor (FIG 3A-1) and earth plug removed from the brass socket and installed socket (FIG 3A-3) ready for the P.P.S.W.F. to be connected.

In (FIG 38), the three connection plugs in the interconnecting lead from the P.P.S.W.F. are simply connected in place of torch earth lead and with motor control lead connected to socket (previously installed) to the The P.P.S.W.F. is now ready for use.

When the 1.5mm three core motor control cable connected to plug (FIG 3 B-5) is inserted to socket (FIG 3B-3), it automatically disconnects the welder feed motor or PUSH MOTOR from the P.C.B in the welder, and diverts its connection to be controlled by the P.C.B in the P.P.S.W.F. (FIG 1-11) through the interconnecting lead (FIG This then links both PUSH MOTOR and PULL MOTOR together and synchronized speed control is achieved by the DUAL MOTOR SPEED CONTROL potentiometer on the P.P.S.W.F. (FIG 1-12).

When plug (FIG 3B-5) is disconnected, normal operation is retained by automatically reconnecting the feed welder motor to the original wiring connection through a switch in the socket (FIG 3B-3). When plugs (FIG 3B- 4-,5 and 6) are detached, the MIG welder is then used normally by reconnecting the welding torch and earth lead.

S FIG 4A displays the compact MIG welder prepared ready for welding. The welding wire is S fed by the feed or PUSH MOTOR to the welding torch FIG 3B 4B display the simple connection of the P.P.S.W.F. to the MIG welder, and the size comparison of the MIG welder and P.P.S.W.F.

OPERATION OF THE P.P.S.W.F.

The welding wire remaining inside the MIG welder (FIG 4B-4) is fed through the eight meter interconnecting lead (FIG 4B-5) along with power and control cables and gas line to the P.P.S.W.F. (FIG 4B-6).

The existing PUSH MOTOR (FIG 4B-7) feeds the welding wire (FIG 4B-4) through a steel S wire feed guide liner (FIG 1-23) in the interconnecting lead (5-13) to the PULL MOTOR in the P.P.S.W.F.(FIG 5-2).

This PULL MOTOR then drives the welding wire te l.ie welding torch (FIG 1-7),connected directly to the brass torch adaptor socket on the P.P.S.W.F(FIG The earth lead (FIG 1- 8) is also connected to the P.P.S.W.F. to the brass female earth socket (FIG 1-17) to provide S1 the return welding current.

The trigger switch (FIG 1-10) on the torch, connected by a 1.5mm two-core trigger control Scable within the inter-connecting lead, initiates both PUSH and PULL MOTORS to start and S stop the wire feed operation.

These motors are powered by the output source of the welder to a P.C.B mounted in the 4 5IS P.P.S.W.F. (FIG 1-11). This P.C.B (consisting of a basic speed control timing circuit and protected by a 5AMP fuse), controls the speed and synchronicity of these motors by adjusting the DUAL FEED SPEED CONTROL potentiometer mounted on the P.P.S.W.F (FIG 1-12).

The output power is transfered to the P.P.S.W.F. by two 35mm power cables inside the interconnecting lead which are connected to the P.P.S.W.F. (FIG 1-13 being the positive and 1-14 being the negative Th-we not only supply power to the P.C.B, but also transfer the welding current required to melt the welding wire.

(FIG-1) displays the P.P.S.W.F. with welding tor h and earth lead connected, ready S" for welding.

0 4 4 9 An additional feature to the P.P.S.W.F. is the REVERSE POLARITY interconnection facility .2S (FIG This plug is connected via a cable to the torch connection. This enables the output polarity of the MIG welder to be reversed by attaching or removing the plug (FIG 5-4) to the female POSITIVE socket (FIG 5-7) or the female NEGATIVE socket (FIG 5-6) respectively.

The earth plug is also removed and reversed in the same manner.

This is done in the event of using flux cored or gas-less MIG welding wire.

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r l I.n The P.P.S.W.F. is a unit made of shaped, cut, and welded sheet metal to fcrm a strong and lightweight transportable unit. It contains the protection fuse,(FIG 5-5) PULL MOTOR, (FIG 5-2) two brass insulated female earth sockets (FIG 5-6 7) one brass torch adaptor socket (FIG 5-3),a firm plastic handle,(FIG and all internal wiring. Two reinforced outriggers are mounted to the base (FIG 5-11), with adhered rubber feet providing extra grip and stability.(FIG 5-12).

The eight meter interconnecting lead (FIG 5-10), is enclosed in a strong rubber tubing to protect all internal cables and hoses. The 40 mm cable gland (FIG 5-1) clamps the interconnecting lead tightly to the feeder, preventing accidental dislodgement or removal.

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Claims (9)

1. A PUSH-PULL SEPARATE WIRE FEEDER is a lightweight, transportable,extension unit, comprising of a drive motor/gearbox and drive roller assembly or PULL MOTOR (similar to that of a MIG welder), controlled by a speed adjusting potentiometer affixed via a PRINTED connec4-e Aot prok.ed by q CIRCUIT BOARD powered by the OUTPUT VOLTAGE of a MIG WELDER, SA fuse/flse holder, with TORCH and EARTH insulated female brass sockets labelled as POSITIVE and NEGATIVE and one insulated brass plug for REVERSE POLARITY connection, WELDING TORCH adaptor socket and associated wiring, enclosed In a sheet metal enclosure an EIGHT METER INTERCONNECTING LEAD attadhed to the rear of the PUSH-PULL SEPARATE WIRE FEEDER by a 40mm cable gland, compring of two 35mm positive and negative power cables, one gas hose,ono tool wie food guido lino, one 1.5mm two core trigger control cable, one 1.5 mm three-core motor speed control cable, and one steel welding wire guide liner connected to three individual insulated plugs and encased in a tough rubber tubing, used to link the PUSH-PULL SEPARATE WIRE FEEDER to an existing typical S IS MIG welding machine. 04 01 a oa O, up the EIGHT METER INTERCONNECTING LEAD are connected to THREE individual E3. The PUSH-PULL SEPARATE WIRE FEEDER of claim 1 wherein PLUG (being the brass torch adaptor plug) of claim 2, connects the 35mm positive cable, gas hose, trigger and wire feed liner within the rubber tubing, from the MIG welder to the PUSH-PULL SEPARATE WIRE FEEDER.

4. The PUSH-PULL SEPARATE WIRE FEEDER of claim wherein PLUG (being the S o brass insulated EARTH plug), of claim 2, connects the 35mm NEGATIVE or EARTH retumrn s 25 cable within the rubber tubing, from the MIG welder to the PUSH-PULL SEPARATE WIRE FEEDER.

5. The PUSH-PULL SEPARATE WIRE FEEDER of claim 1 wherein PLUG [3 of claim 2, connects the PUSH MOTOR from the MIG welder (via a 1.5mm 3-core cable within the rubber tubing), in parallel to the PULL MOTOR of the PUSH-PULL SEPARATE WIRE FEEDER. (4\ O'3 -8-

6. The SEPARATE WIRE FEEDER of claim 1 wherein the synchronized speed of motors of claim 5 are varied by the speed control potentiometer (via the P.C.8) in the PUSH-PULL SEPARATE WIRE FEEDER, from plug 3, through the INTERCONNECTING LEAD of claims 1 to

7.The PUSH-PULL SEPARATE WIRE FEEDER of claim 1, comprises of THREE (3) separate insulated brass socket adaptors, two are similar OUTPUT POWER female sockets labelled as POSITIVE(+) and NEGATIVE for EARTH and TORCH polarity, and the third socket adaptor for connecting the MIG WELDING TORCH to the PUSH-PULL SEPARATE WIRE FEEDER.

8. The PUSH-PULL SEPARATE WIRE FEEDER of claim 1 features a REVERSE POLARITY interconnection facility, whereby the output polarity is REVERSED by connecting a fitted TORCH plug to a selected OUTPUT POWER female socket of claim 7, with the EARTH plug connected to the opposite female socket.

9. The PUSH-PULL SEPARATE WIRE FEEDER of claims 1 is constructed of a strong IS welded sheetmetal enclosure, with attached outriggers and rubber feet to the base, and '.easily carried by an attached plastic handle. o

10. The PUSH-PULL SEPARATE WIRE FEEDER of claim 1 when connected to a MIG welder via the INTERCONNECTING LEAD of claims 1 to 5, supplies the welding current, gas, wire feed and earth retum for welding metals,

11. The PUSH-PULL SEPARATE WIRE FEEDER unit substantially as herein described with reference to the accompanying drawings. *a N c 0. CL^M C Q c W 2 B: 1 I (Name of applicant) (Dto) a L a