US2475376A - Soldering iron - Google Patents

Description

F. L- DARLING SOLDERING IRON July 5, 1949.

m P w m F m m ATTORNEY.

Patented July 5, 1949 UNITED STATES PATENT OFFICE SOLDERING IRON" Frank L. Darling, Hollywood, Calif., .assignor a A. P. Drayto'n, Los Angeles;:alif.

Application February 28, 1946, SerialNo. 650,812

3 Claims.

1 My invention relates to soldering irons of the electrically heated type. its objects:

L 'io provide an iron of relatively light weight.

2. To provide an iron in which the expansion of the heated part serves as a thermostat to con trol a circuit breaker.

. To provide an iron in which the temperature may be set by the user and automatically controlled for any heat from zero to 560 degrees.

. To provide for the operation of the circuit breaker to open the circuit by a pull action, thereby avoiding stacking the connection and causing inaccurate operation.

. To provide an iron with a thermostatic control such that the circuit will be opened at the proper time even though the contact points should Stick.

6. To provide an iron with a new kindof tip that can easily and cheaply be replaced when nec essary.

7. To provide means to reduce to a minimum heat conduction from the iron proper to the handle.

Other objects will in part be obvious and in part will be pointed out hereinafter.

To the attainment of the aforesaidobjects and ends the invention-further resides in those novel details of construction, combination and arrangement of parts, all of which will be first described in detail hereinafter and will then be specifically pointed out in the appended claims, reference being had to the accompanying drawing, in which:

Fig. 1 is a plan view of an iron according to my invention.

Fig. 2 is a part central horizontal section and part plan view of the same with the cover part of the handle omitted.

Fig. 3 is a central vertical longitudinal section of the handle and the parts contained therein.

Fig. 4 is an inverted plan View of the circuit breakerplate and the parts carried by it.

Fig. 5 is a face view of the handle-coupling member looking from left to right in Fig. 3;

Fig. 6 is a section on the line 6-6 of Fig. 2 looking in the direction of the arrow, the insulation spacers and connecting screws being omitted.

Fig. '7 is a detail section, on the line l-l of Fig. 6, of the iron-coupling plate.

Fig. 8 is a detail view hereinafter specifically referred to.

In the drawing, in which like numerals of reference indicate like parts in all figures, l represents the part of the instrument to which the heat is applied (commonly referred to as the "iron). In

The invention has for- 2, my instrument the part I is made of a suitable aluminum alloy. It iscylindrical in form and has a-fiange 2 and a pyramidal tip 4 connected with theflange partby a neck 3. The pyramidal tip 4 is covered by a stamped metal (copper) sheath 5 whichis r'emovably held tightly in place by crimping over portions ofits inner edge as at 5*. At its innerend-the iron I is threaded into the-threaded hole 1 of a coupling plate or ring ii. l7he iron I isbored as at l to receive the anchor for-the pull wire-29,.later again referred to.

ihe plate t has screw holes 3 for connecting screws to join-platento the intermediate ring i l, insulators l2 being interposed through which insulators the connecting screws are passed. The plate 6 also has air holes}.

A heating: coil I0 is placedon the member l between the-fiange 2 and-theiron-coupling member 8; andametal shield IT is placed over thesame, as shown in Figs. 1 and 2.

The handle-unit is best shown in'Figs. 2 and 3 by reference-to which itw-ill be seen that H3 is the handle of suitable: material that is a poor conductorof heat- Thehandle is 'hollow and is cut apart as at 2Eltoprovide a removable cover 22 which is heldin-place by screws-23, the longer one of which passes through a hole in the insulation base plate 25 and threads into a fixed part of the handle while the shorter screw is threadedinto-a saddle 21. The outer end of the handle is bored-and bushed as at 24 to pass in thepower'wires 56 and 57. The handle it is mounted on the mounting bushing l5 and held thereon by a screw l9.- Themounting bushing I5 is integrally formed with ahandle-coupling flange it which isconnectedto-ringl l by screws 16 which pass through holes 8 in fiange I4" and insulation l3,-and are-screwed'irito'ringv H at-places stagger-ed with'res-pectto the screws and screw holes :ofplate 6.

Flange idalso-has-yent-holes: W. The handle hasrecessed portions l8 in which' the circuit breaker base plate flr rests-and is held in place by the cover 22.

Mounted on the base plate 25 is an L-shaped lever 35 whose longer leg carries a contact point 31, and whose shorter leg is pivoted at 38. A pin 38, carried by the longer leg, projects through a slot 39 in the base plate 25 and is engaged by a return spring Mi. The spring ill is anchored at 52 and passes over a fixed pin ll on the plate 23 so that the spring All constantly urges the lever 35 toward its circuit-closing position. Also mounted on the plate 25 is a lever iii that is pivoted at one end, as at 44, and carries a contact point iii to cooperate with contact point 31, the extreme or free end of the lever being held in contact with a temperature regulating cam 52 by means of a spring 48 which is anchored at '59, passes over a fixed pin 49 and engages a pin 49 on the lever 43. The pin 46 passes through a slot ill.

The cam 52 is carried by an adjusting bolt or screw 9i that passes through and is soldered to a washer M. The bolt also passes through a hole in plate 25 and the cam 52 is held to the bolt by a nut 53. The washer 54 has a mark and the handle has H and L marks to indicate high and low temperature adjustments.

The wire 29 is attached in any suitable way (as by welding) to the screw 32 and to the anchor 39. The anchor 30 is held in place by the key pin 31 in the neck 3. The screw 32 is ad justably threaded into a slide 21 which works in a groove or recess 26 in plate 25 and has a pin 29 to engage the shorter arm of the lever 35. A nut 93 holds screw 32 in place. When the tool is cold, pin 28 is free of lever 35 but when the tool heats up, expansion of the member I exerts a pull on wire 29, causing pin 28 to contact lever 95 and. when the right temperature is reached moves lever 35 to break the circuit. The temperature at which the circuit is broken depends on the position to which cam 52 is set. The tool is set for its maximum heat when lever 43 is engaged by the low side of the cam, and by turning the cam settings for any desired degree of heat less than maximum can be had and controlled at that setting. As shown, the tool is set for maximum heat.

One power wire 58 runs direct to coil 19, an other 57 runs to pin 46, while a third wire 55 connects coil it with pin 38. A piece of sheet insulation 34- prevents possible short circuits to bushing I5.

The tool which I have constructed accordin to this disclosure can be set to operate from a maximum of 500 watts down to 50 watts. As will be seen, the control is very positive as it is operated by the expansion of the part i actin on the circuit breaker with a pull through wire 29 sufficient to break apart the points, even though they should stick more or less. Of course, as will be obvious to anyone skilled in the art, the wire 29 should have a lesser co-efiicient of expansion than the material of part I or it must be kept cooler than part I or both. The coupling 9, 12, II, I3, [4 not only lessens heat conduction between the handle portion and the heating portion of the tool but serves to ventilate somewhat the space containing the wire 29 thereby cooling it below the temperature of part I.

The new style copper tip is an important improvement. These tips can be stamped from onesixteenth inch copper at low cost and sold to the users of the tools as replacement points. This does away with the usual practice of screwing copper tips into the heating elements; as these points oxidize rapidly, it is frequently impossible to screw the tips out without ruining the irons for replacement. My tip 5 can be easily pried off with an ordinary screw driver and a new one can be installed instantly.

By the new construction of my tool I have reduced the weight of a 500 watt iron to less than one-half of that of one of the best irons now on the market.

From the foregoing description, taken in connection with the accompanyin drawing, it is thought that the construction, operation, and advantages of the invention will be clear to those skilled in the art.

What I claim is:

1. In an electrically heated soldering iron, two units one of which is a chambered heating unit and the other of which is a handle and a heatcontrolling unit; a heat-insulating and chamber ventilating coupling joining said units together; and means anchored to the heating unit and lying in the chambers of said units and mechanically connected to the heat-controlling unit operable by the expansion and contraction oi the heating unit for effecting operation of the heat-controlling instrumentalities of the heatcontrolling unit.

2. In an electrically heated soldering iron, heating unit and a handle, said units having connecting chambers; a ventilated coupling be tween said units and effecting communication between said chambers and. the atmosphere; a circuit make and break device mounted in said handle; and a pull connection between said device and the heating unit operable by the expan-- sion and contraction of the heating unit in use, said pull connection lying within said chambers.

3. In an electrically heated soldering iron, expansible and contractable element to be heated which has a bore and a tip; an electric heating coil on said element; a handle having a chamher; a ventilated insulated coupling between said element and said handle and communicating with said bore and said chamber and the atmosphere; a circuit opening and closing device mounted in said handle and including a shiftable operating element; a wire anchored at one of its ends in said bore and connected at its other end to said shiftable operating element; and an elec tric circuit including said heating coil and said circuit opening and closing device.

FRANK L. DARLING.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number

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