US2904669A - Arc current controlling apparatus for welders' helmets - Google Patents

Description

Sept. 15, 1959 G. F. TOEBE ARC CURRENT CONTROLLING APPARATUS FOR WELDERS HELMETS Filed Sept. 18, 1958 INVENTOR GEORGE F. TOEBE ATTORNEYS United States Patent ()filice Patented Sept. 15, 1959 ARC CURRENT CONTROLLING APPARATUS FOR WELDERS HELMETS George F. Toebe, Chippewa Falls, Wis. Application September 18, 1958, Serial No. 761,877 1 Claim. (Cl. 219-147) This invention appertains -to safety apparatus for welders, and more particularly to va.novelmeans for automatically controlling the closing movement of the dark glass of a welders helmet and are circuit upon the touching of the weld rod with the work, and isan improvementon the Morrell patent (assigned to applicant) No. 2,778,928, issued January 22, 1957.

One .of the primary objects of the present invention is to provide a new and novel means for actuating and controlling the main switch (employed for releasing the dark glass to permit the same to move to an operative position and to .close the control switch), whereby to insure a positive and desired operation thereof.

Another salient object .of the invention is to provide ,means for urging the main switch to a closed position and for holding the switch in such .position by .a spring, with a solenoid operated catch for releasing the switch to permit the same tomove under the influence of the spring; and a solenoid operated means for returning the switch against the influence of the spring to an openposition for .re-engagemcnt by the release catch, the arrangement being such as to eliminate the dashpot as .employed in the mentioned Morrell patent.

A further important object of my invention .is the provision of a novel and simplified form of circuits and solenoids to :bring about the ,desired safety features for .the welder.

With these and other objects in view, the invention consistsin the novel construction, arrangement and formation of parts, as will be more specifically described and claimed, and illustrated in the accompanying drawing, in which drawing the single figure is a diagrammatic view showing the wiring circuits and parts actuated by the opening and closing thereof.

Referring to the drawing in .detail, the letter H generally indicates the helmet and .C the novel circuits used in conjunction with the helmet .and forming a .part of the invention.

The helmet His of the same type and character shown in the Morrell patent, and in the present application the helmet has .only been shown diagrammatically. The helmet .isof the general type and character as is now in common use and the same is in the nature of a shield held on the welders head by pivoted head straps (not shown).

The helmet is provided with a visor 1 having slidably associated therewith a dark glass or shutter 2. The dark glass or shutter 2 is mounted for sliding movement toward and away from the visor and has secured thereto a depending shank 3. The shank3 on one side is provided with akeeper notch 4 and on the other side adjacent to its lower end with a catch nose 5. A switch operating ear '6 is also formed on the lower end of this shank. A contractile coil spring 7 has its opposite ends secured respectively to the lower end of the shank 3 and to a rigid part of the helmet and this spring functions to normally urge and hold the dark glass or shutter 2 inaraised position in front of the welders eyes. Also slidably mounted onthe helmet is an operating rod 8 and the same is provided with a hand grip 9 to facilitate the sliding .of the rod up and down by the welder. The upper end of the rod 8 ,is provided with a laterally projecting nose 10 for interengagement with the nose 5 of the shank 3. A contractile coil spring 11, has its opposite ends secured respectively to the rod 8 and to ,a stationary part of the helmet and this spring functions to normally hold the operating rod in a raisedposition and above the nose 5. .It can be seen, however, that when the dark glass 2 and its shank 3 are .in a raised position that by pulling .downon the hand grip 9 and the rod 8, the nose 10 will engage the nose 5 and hence draw the shank 3 and the .dark glass or shutter 2 therewith.

.Mounted .for horizontal sliding movement on the helrnet is a latch bar 1-2. For-med on or carried .by the ,innerend of the latch bar 12 is an armature or plunger core 13 of a solenoid coil 14. vA spring 15 normally urges the plunger 13 and the latch bar 12 toward the shank 3 ,and when the shank 3 and the dark glass 2 are ,in their lowered position the latch bar 12 engages in the keeper .notch 4 and holds the shank and the .dark glass in their lowered positions against the tension of the spring 7. When arcircuit ,isclosed through the solenoid coil 14, the .latch 12.is retracted and theshank 3 and dark glass 2 are quickly moved to a raised operative-position .by the spring 7.

Also carried by the helmet is a control switch 16 and the same includes spaced .upper and lower leaves ,17 and 18 and an intermediate resilient .leaf 19. All of the sleaves are formedfrom electricconducting material. The .upper leaf .17 is provided with a contact point 20, and the lower leaf 18 is .provided with a similarcontact point 21. The intermediate resilient leaf 19 is provided with oppositely extending contact points 22 and 23. The (normal resiliency of the leaf 19 holds .the contact 23 in electrical engagement with thecontact 21 and the leaf 19 'is extended to form a foot 24, which .is disposed in the .path'ofthe movement of the operating ear 6. When the shank 3 is in its raised position, as shown in dotted lines, the ear .6 engages the foot 24 and moves the leaf 19 against its inherent resiliency to a raised position, moving the contact 23 away from the contact 21 and moving the contact 22 in electrical engagement with the contact 20. All of the leaves are separated by blocks of insulation 25. The helmet carries a safetyswitch 26, which is of the type to break circuits when the straps-of the'helmet are moved to an inoperative position. Briefly, the switch includes a stationary annular casing 27 and an axially disposed rotor 28 :rnovable with the straps. The housing includes spaced contacts 29, 30 and 31. The rotor 28 includes spaced contacts 32, 33 and 134. With the helmet in place and the straps in their lowered position the contacts 32, 33 and 34 engage respectively the contacts 29, 30 and 31. With the helmet straps in their raised inoperative position, the mentioned contacts are moved away from one another, but contact 33 is moved into electrical engagement with the contact 31. The purpose of this safety switch and the arrangement of the contacts will be later described. All of the parts mentioned are carried by the helmet as suggested by the broken lines in the drawing.

in conjunction with the helmet and the parts just described, I utilize the novel wiring circuits C which will now be set forth. Heavyduty welding lines 35 and 36 are provided which lead from any suitable source of electrical energy, or power, such as a generator 37 forming a part of the welding machine (not shown). As in the usual practice the wire 36 is electrically connected with the work W. A branch main welding line or wire 38 is electrically connected with the holder 39 for the weld rod 40. Operating in conjunction with the main welding circuit is a main control switch 41 and this switch includes a stationary body section 42 carrying spaced electrically insulated contacts 43 and 44. This main switch 41 includes a movable section 45 carrying spaced apart but electrically connected contacts 46 and 47. The movable section 45 is operated by the plunger 48 of a solenoid 49. A spring 50 normally urges the plunger and the movable section 45 of the switch toward the stationary section 41 when the solenoid is deenergized. With the movable section 45 in engagement with the stationary section 41 contacts 46 and 47 electrically engage contacts 43 and 44 and electrically unite the same.

The main line 35 is electrically connected with contact 44 and contact 43 is electrically connected to the wire 38 by a branch wire 51. So far, it can be seen that with the contacts 43 and 44 electrically connected as just described, the main welding circuit is completed and current flow is from generator 37, wire 35 through switch 41, wire 51, wire 38, weld rod 40, work W through wire 36, back to the generator 37. When the solenoid 49 is energized the plunger 48 and the movable section 45 are drawn back against the tension of the spring 50. The plunger and the movable switch section 45 are held in this position against the tension of the spring 50 by a releasable catch 52. The catch 52 includes a vertically movable block 53 carried by the plunger 54 of a solenoid 55. Pivoted to the block 53 is a pivoted latch lever 56. The lever is free to swing in one direction and its movement is limited in the opposite direction by a stop pin 57. With the movable section of the switch 45 in rear of the pivoted latch nose 56 the latch nose, due to its engagement with the pin 57 holds the movable switch section 45 in its retracted position against the tension of the spring 50. It can be seen that when the movable section 45 is in a circuit closed position and the solenoid 49 is energized, then the switch section 45 moves away from the stationary section 41 and engages the latch lever 56 and rocks the same on its pivot away from the pin 57 until the movable section 45 rides past the latch lever. At this time, a light tension spring 58 moves the latch lever back to its normal switch holding position. When the solenoid 55 is energized, the block 53 and the latch nose 56 are bodily lifted out of the path of movement of the movable switch section 45. A spring 59 is employed for normally holding the block 53 and the latch lever 56 is a lowered position when the solenoid is de-energized.

The opposite terminals of the solenoid 55 are electrically connected respectively with a wire 38 and a conductor wire 60 which leads to contact 29 of the safety switch, which is in engagement with the contact 32 (the helmet being in operative position). Contact 32 has electrically connected therewith a wire 61 electrically connected with one terminal of the solenoid coil 14 and the other terminal of this coil has electrically connected thereto a wire 62 which leads to the contact 30 of the rotatable switch. Contact 33 has electrically connected thereto a return branch wire 63, which is electrically connected with wire 35. A fuse link 64 can be incorporated in the length of the wire 63 if such should be desired. With the weld rod 40 in engagement with the work W current flow is as follows: from the welder 37, through wire 36, work W, weld rod 40, wire 38 through coil 55, wire 60, through safety switch 26, wire 61, through coil 14, wire 62 and safety switch 26, through wire 63 back to the generator. This energizes the solenoid 14 and the latch bar 12 is moved away from the shank 53 against the tension of the spring 15. Spring 7 immediately moves the dark glass 2 to its raised operative position. At this moment, the circuit is not closed through the main welding circuit in view of the fact that switch 41 is in its open position. Upward movement of the shank 3 operates the resilient leaf 19 of the helmet switch 16, and consequently, contact point 22 electrically engages contact point 24). It is to be noted that leaf 17 carrying contact point 20 is electrically connected by a branch wire 65 with wire 61 and that the intermediate resilient leaf 19 is electrically connected to wire 62 by a branch wire 66. Consequently, coil 14 is now shunted through wires 62, 66, leaf 19 and leaf 17, wire 65, and wire 61. At this time, with the shunting of the coil 14, solenoid 55 is energized and current flow is as follows: generator 37, wire 36, work W, weld rod 40, wire 38, through solenoid 55, wire 60, through safety switch 26, wire 65, through leaves 17 and 19 of switch 16, through wire 66, through wire 62, safety switch 26, through wire 63, wire 35 back to generator.

With the energizing of solenoid 55 catch block 53 is raised and the spring 50 will force the movable section 45 of main switch 41 to a closed position. At this time, the main welding circuit is closed, and as stated heretofore, current flow is from generator 37 through wire 36, work W, weld rod 40, wire 38, wire 51, through section 41, through wire 35 to the generator. The welding can now he proceeded with.

When the welding is completed, and the weld rod 40 is removed from the work W, the dark glass is pulled down by the operator by actuating the knob 9 and the dark glass will be held in this lowered position by the latch 12. At this time, leaf switch 19 of the helmet switch 16 will return to its normal position and contacts 21 and 23 will be in engagement. The leaf 18 of the helmet switch 16 are electrically connected to contact 34 of the safety switch 26 by a wire 67 and contact 31 of said switch is electrically connected to one terminal of the solenoid 49 by a wire 68. The other terminal of the solenoid 49 is connected by a branch wire 69 to the main line 36. At this time, it is to be noted that wire 69, for safety purposes, has interposed therein a safety switch 70 embodying a pivoted switch lever, which is in its closed position when the movable portion 45 of the main switch 41 is in its closed position with the stationary section 42. With the shutter or dark glass 2 in its lowered position and leaves 18 and 19 of helmet switch 16 in circuit closed position, current flow is as follows: generator 37, wire 69, though solenoid 49, through wire 68, safety switch 26, wire 67, switch 16, wire 66, wire 62 through safety switch 26, through wire 63 back to generator 37. With the energizing of solenoid 49 the switch 42 is opened and held in that position by the catch 52 and the welding circuit is now broken.

When the welder moves the helmet and moves the helmet straps to an inoperative position, the contacts 32 and 29 are disconnected as are the contacts 30 and 33. This insures the safety of the welder.

Hence, welding cannot continue until the helmet is again pulled down in welding position.

From the foregoing description, it can be seen that I have provided an improved and simplified mechanism for protecting the welder.

Changes in details may be made without departing from the spirit or the scope of this invention, but what I claim as new is:

In combination with a welding helmet, a movable shutter and an arc circuit controlling apparatus, spring means normally moving the shutter into a raised eye protecting position, a solenoid operated catch for holding the shutter in a lowered inoperative position against tension of the spring, an arc welding circuit including a welding electrode and the Work, a normally opened main switch in said arc welding circuit, spring means normally holding the switch in a circuit closing position, solenoid operated means for moving the switch to an open position, a catch for holding the switch in an open position against the tension of the spring, solenoid operated means for moving the catch to a released position, a branch circuit including the solenoid of the catch for the shutter energized upon the engagement of the weld rod with the work normally in series with the solenoid of the release 5 6 catch for the main switch, means shunting the first menmain switch upon the lifting of the Weld rod from the tioned solenoid upon movement of the shutter to a raised Work for opening said main switch. eye protecting position, whereby to bring about increased current flow through the solenoid for the catch of the References Cited in the file of this Patent main switch and the energizing of said solenoid to per- 5 UNITED STATES PATENTS mit the closing of the main switch under the influence of 2,778,928 M 0 IT 611 Jam 22 1957 its spring, and means for energizing the solenoid of the

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