Push-button operated electric switch
United States Patent 2475696

This invention relates to electric switches and has among its objects to provide a switch that is proof against the passage of liquid or gas that may corrode the contacts, to provide a selfcontained switch that is applicable to articles such as electric handlamps, and to provide such a switch...

Peter, Cornish John
Application Number:
Publication Date:
Filing Date:
Primary Class:
Other Classes:
200/302.2, 200/564, 200/572
International Classes:
H01H13/02; H01H13/06
View Patent Images:
US Patent References:
2192296Circuit closing device1940-03-05
2190299Electric switch1940-02-13
2086066Electric switch1937-07-06

Foreign References:

This invention relates to electric switches and has among its objects to provide a switch that is proof against the passage of liquid or gas that may corrode the contacts, to provide a selfcontained switch that is applicable to articles such as electric handlamps, and to provide such a switch that is available for the control of more than one circuit.

According to the invention the switch comprises terminal contacts and a circuit-closing ele- 1. ment sealed within a casing, and control means for the circuit-closing element projecting outside the casing.

The circuit-closing element may conveniently take the form of a ball, drum, cylinder or plung- l er of conductive metal or it may comprise a body of non-conductive material, such as a plastic material, in or upon which conductive strips or surfaces are fitted or formed for engagement of the terminal contacts. 2 The invention further comprises the features of construction hereinafter described.

The invention is illustrated, by way of example, in the accompanying diagrammatic drawings.

Figure 1 is a longitudinal section of a construe- 2; tion of the switch.

Figure 2 is an end view of the switch represented in Figure 1 viewed from the operating end of the switch.

Figure 3 is an end view of the switch represented in Figure 1 viewed from the opposite end of the switch.

Figure 4 is a cross-section taken on the line 4-4 of Figure 1.

Figure 5 is a longitudinal section of a modified construction of the switch.

In carrying the invention into effect, by way of example, in the construction of a self-contained switch that is proof against the passage of liquid or gas and that is adaptable to a hand lamp, such as a miner's electric lamp, as illustrated in Figures 1 to 4 of the accompanying drawings, the casing consists of a body 1 of ebonite or other insulating or non-conductive material such as a plastic material, that comprises lhree parts of differing and graduated diameters ixially disposed and is closed at the smaller end, ,he first part, of largest diameter, having a bore ;hat is in two parts of differing diameters, the 50 part 2 of the bore of larger diameter being at ;he outer end of the casing and being formed rith a screw thread 3 for the reception of a closng plate or ring 4 having a cooperating threaded )ortion. The second part 5 and the third part 6 655 of the casing, of the smaller diameters, are bored each to an appropriate diameter as at 7 and 8.

The second and third parts 5, 6 of the casing serve to house the spring-pressed plunger 9 made of ebonite or other non-conductive material or of a plastic material, which is formed with a sterm 1 of a diameter slidably to fit the bore 8 of the third part 0 of the casing, of smallest diameter, and with a head 11 that is a clearance 0 fit within the bore 7 of the second part 5 of the casing. The spring 12 is helical and is disposed between the head I i and the shoulder 13 formed by the reduction of diameter at the junction of the bores 7, 8 of the second and third parts 5, 6 of the casing. The bore 7 of the second part 5 is continued for a short distance into the first part of the casing i and there are here disposed two terminal contacts 14, 15 extending radially through the wall of the said part and having 0 pointed or spring ends protruding into the bore 7, or as may be required. Within the inner part IS of the bore of the first part of the casing I there is disposed a ball 17 of silver, brass or other conductive metal that is a rolling fit in the bore.

SThe head iI of the spring-pressed plunger 9 is shaped to avoid engagement with the terminal contacts 14, 15 and also to form an axial recess I8 of spherical curvature to serve as a seat for the ball I7. Thus, so long as the ball 17 is not Ssubjected to pressure to overcome the force exerted by the spring-pressed plunger 9, the latter will press the ball out of engagement with the terminal contacts 14, 15. It is the purpose of the operating element 19 to control this tendency at will.

At the shoulder formed by the change in diameter of the parts 2 and Is of the bore of the first part of the casing there is seated a transverse diaphragm 20 of rubber or a synthetic material of the required elasticity effectively sealing the bore against the passage of liquid or gas and retained in position by a retaining ring 21.

The ring 21 may be of ebonite or other nonconductive material or of plastic material.

The operating element 19 is formed of ebonite or other non-conducting material or of plastic material and comprises a cylindrical body 22 that is a sliding fit within the outer bore of the first part of the casing and is formed at the inner end with a cylindrical extension 23 of reduced diameter to pass freely through the diaphragm-retaining ring 2 and to bear upon the diaphragm Re by means of its end face 24 which is formed to a spherical curvature to correspond with that of the ball 17. At the outer end the element 19 is formed with a cylindrical part or extension 25 of 42, 43 and 44 and the ball 4 a diameter to fit slidably in the closing ring or of silver but may be of othe plate 4 of the casing I and of a length. to. extend., alloy. The ball is a clearai outwardly to serve as a knob or handle-by which, and while remaining alway the operating element 19 may be manipulated. 5 common terminal contact 4 A sealing washer or packing ring 26 of a plastic, the direction of the outer i material or other material for the purpose is re- plunger 38 under the acti cessed into a peripheral channelata.,:position:.to. The-plunger 38 may be of a bear upon the inner surface of the bore of the:, of.,the housing or casing. closing ring or plate 4. The operating element, 9 ..10 reduced in diameter to clear is thus adapted to press the ball 1.T' into engage- 4V4 and the outer end 4 ment with the terminal contacts,, 1.4,i 15;'through., concave curvature to fit the the medium of the diaphragm 20. The positions The operating element is of the operating element 19 may be-determined: ofwhich is a cylindrical b( by the engagement of a spring ball catch 2-7'set 15- axially through a retainini radially in the wall of the casing, I with any.one. determined by a shoulder of a number of circular recesses 28 formediiduthe,. crease, in diameter of the bo bottom of a groove or channel 29 in the peripheral is received in a correspond surface of the body 22 of the element and set" at the-inner side of the retaini a small angle to a plane transverse to the axis. 20 truding part of the cylindr The engagement of the ball catch 27 in the groove- its rotation by hand to effec or channel 29-constrains the possible: movement: switch; For this purpose of the element to a limited movement of rotation of:the- cylindrical body is in that is accompanied by: a slight axial movement is set, in contact with a sin to move the ball 17 into, or to permit.it -to move! 25 tary: end face 51 formed o out of, contact with the terminal contacts:: 14and the-operating element whic 15 the: recesses determining the required posi- length. sufficient to permit tions. inclined end face 51 and wl The switch may be mounted upon the-lamp; or 53.by ,which it may move other article to which it is applied asa may be; 30 diaphragm 41. The second required by the construction of the lamp-and thet- ing-element is constrained electrical connections may be made: to. thee ter- the axial direction by the minal contacts:in any conventionalimanner, such: of the housing or casing o as by soldering, by the use of clamping screws- engages in a longitudinal c] or by other means; 35 .the.-periphery of the cylinc The switch hereinbefore described; may, be- ring;48 has'the inner face r adapted to control two or more circuits in- a-sim- screw-threaded at 56 to e: ple manner as indicated, for example in-broken: formed:on the periphery of lines in Figure 1,.by the provision:of aistrip con- 32. at thelouter end. The r tact 30 extending longitudinally along thei:bore: 40 to retain the parts of the 16; of the- casing from one of :the: terminal con- the relative positions to pe; tacts 14, 15 and disposed so as always to-.bei:in:r The diaphragm 41, of contact with the ball 17 throughout, its axial. material, is advantageousl movement and: an additional terminal contact l- I- tively thick annulus of an with-which the:ball II may come into .contact` 45. ly:greater than that of the when retracted from the -two terminal contacts.- part 52 of the operating 14, 15, to a determined extent under: the force:of:: axial pocket-like part 57 o the spring-pressed plunger 9. The strip contact.: into,,which the said stem 30 may be a spring contact. which pressure is applied It isnot: essential that. the body of the-casing. 50.diaphragm 41 is maintain should be formed in three parts of: differing :di-. shoulder 40 of the bore ameters. The:outer shape-ofthecasing;I maybe, casing 32 by a locking ri] adapted to.the: article.with.which the.:switch is:to bore:. bemused' In the operation of thi In a construction of switch adapted for the con- 55 of the.outer or first part troL of two circuits alternatively, as.illustrated .in element relatively to the:Figure 5 of:the accompanying drawings; the body. the latter to move axially of the:housinglor:casing:is a'.cylinder:32',of ebonite- against the force exerted or other non-conducting material, such:as-a plas& plunger. 38, into contact w tic material, that is moulded or.otherwise formed: 60 tact. 44 and thus. establish with a-closed:end 33 and:a cylindrical bore34-that: said.,contact and the com may have the inner closed, end: 35~.centrally re- 42.-. On further. rotation o cessed at.36 to form a seating for:a.helical:spring, operating element in the sI 37 to act upon:the plunger 38 'and:increased.i.in reverse direction, the plun diameter at 39, towards the outer end:to form;:a 65:force the ball 45 out of c shoulder 40 upon. which-may:be seated;.the :flx- pin contact 44 and thus b ible diaphragm 41. At: a. position..at,:th-e inner, ther-rotation permits the t side of the shoulder- butnot'; far;: removed, ethe: plunger 38:into contact w housing or casing is prepared:to: receive:iatr'one, tact 43 for the closure of side a common terminal, plug -contact. 42V and iirm 70: The parts of the operati] opposed positions but spaced: apart th-e comple- taiinng' ring may be of tl mentary pin contacts 43,; 44,: that protrude, intor fore*mentioned or of other the bore 34: of the housing: or casing andi:have., the--purpose. The retainii their inner. ends bevelled' or otherwise shaped, ripherally:screrewathreaded; effedtivel:yto-oontact'the:ball 4C. The.contacts 75ffor mounting the switch.

5 are advantageously r conducting metal or nce fit in the bore 34 s in contact with the 2 is pressed always in pin contact 43 by the on of the spring 37.

material such as that It has the outer part Sthe inner pin contact 6 advantageously of ball.

in two parts, the outer ody 47 that protrudes g ring 48 to a degree 49 formed by an in,dy 49, which shoulder ing annular recess at ing ring 48. The proical body 49 serves by ct the operation of'the ;he inner end face 50 clined to the axis and' nilar and complemenn the second part of. h is a cylinder 52 of a.

the formation of the hich has an axial stem-.

the ball through the part 52 of-the operatfor movement only in: provision in the wall f a guide pin 54 that.

hannel or groove 55iin ler 52. The retaining'.

ecessed and internally: ngage a screw thread; Sthe housing- or casinging 48 is thus effective: operating element in rmit them to function.

rubber or a synthetic.

y provided as a relainner diameter slightstem 53 of the second element and with- an; f relatively thin walls 3 extends and.through to the ball 45: The: ed in position on the 39 of the housing or ng 58 fitting the saide switch the rotation..

t 47 of the operating second part 52 impels to press the ball 45; by the spring-pressed" ith the inner pin cona circuit through the. mon terminal contact if the first part of: the ame.direction or in the ger 38 is permitted to ontact with the inner reak the circuit. Fur)all to be forced by the ith the outer pin conthe second circuit.

ng element and the reie materials hereinbeSmaterials adapted for ng ring 48 may be pe,to serve also as means; By predetermining the distance between the contacts 43, 44 and the angle of the inclined end faces 50, 51 of the operating element the switch may be adapted as a micro-switch, the travel of the ball 45 being reduced as required for example to 20 thousandths of an inch.

The switch according to the invention may be used with advantage particularly for marine equipments and in all situations where the content of moisture in the air is high.

I claim: 1. An electric switch comprising an insulating casing having one end open and the other end closed by an integral wall, said casing further having at least three internal bores of different diameters, the smallest bore being at the closed end and the largest bore being at the open end with an intermediate bore therebetween, a shoulder formed on the intermediate bore by the largest bore, a flexible diaphragm held against said shoulder to provide a seal between said largest and intermediate bores, terminal contacts extending through the wall of the casing into the intermediate bore, a circuit-closing element movable lengthwise of the intermediate bore for engagement with said contacts, a plunger in slidable engagement with the wall of one of said bores, a spring holding said plunger in engagement with the circuit-closing element to urge the latter toward said diaphragm, and an operating element fitting within the largest bore and being rotatably adjustable therein for movements axially of the bore to press the diaphragm into engagement with the circuit-closing element for selectively maintaining the latter in circuit-opening or circuit-closing position.

2. An electric switch according to claim 1, in which the possible movement of the operating element in the casing is determined by a guide channel or groove.

3. An electric switch according to claim 2, in which the operative and inoperative positions of the operating element are determined by spaced recesses and cooperating stop devices.

4. An electric switch according to claim 1, in which the operating element is comprised of (t more than one part and the parts are relatively movable on the rotation of one part to effect an axial movement of a second part for the purpose of moving the circuit-closing element.

5. An electric switch according to claim 4, in which the re:atively movable parts of the operating element are provided with co-operating cam surfaces.


20 REFERENCES CITED The following referenlces are of record in the file of this patent: UNITED STATES PATENTS 25 Number Name Date 1,132,997 Apple -------_____ Mar. 23, 1915 1,961,146 Harrington _______ June 5, 1934 2,086,066 Churchill _--------- July 6, 1937 2,190,299 Van Valkenburg ____ Feb. 13, 1940 2,192,296 Boynton _--------- Mar. 5, 1940 FOREIGN PATENTS Number Country Date 238,276 Great Britain --___ Aug. 20, 1925 35 817,068 France --______-- May 15, 1937 818,065 France ----------- June 7, 1937