Патент USA US2130706код для вставки
Sept. 20, 1938. H. M. SALMOND 2,130,706 ELECTRICAL SWITCHING DEVICE Filed July 2, 1934 4 Sheets-Sheet l \r48 . JW 7421M /3J/ Qua; Sept. 20, 1938. H. M. SALMOND 2,130,706 ' ELECTRICAL SWITCHING DEVICE Filed July 2, 1954 4 Sheets-She‘et 2 52 56' Fig.6a. ,nI|wnm m f E\ aB _ y ., 341375157 3 / ./ 5 6/ I 5 5_. 65 95 w /// 74 52 5‘9) 5 8 7 Septf 20, 1938. H. M. SALMOND ‘ 2,130,706 ELECTRICAL SWITCHING DEVICE Filed July 2, 1954 4 Sheets~Sheet 3 / #04, Z Wz/M Sept. 20, 1938. H. M. SALMOND 2,130,706 ’ ELECTRICAL SWITCHING DEVICE Filed July 2, 1934 4 Sheets-Sheet 4 W013% Meg “UNA/MW I_o.._o4M "1E 1%”/ __ _Aw \1-l.|9 |I -l _ .r|9 / ‘m I 1.X 70 D. @ MW n. \ /a \\n _i_ Mi 9W m00// 57_ il o‘? E 9 %/r I7 w T ® @ l\F % A? % /@ _ /® .w @ WW a “i‘w? JJU LMWAY/ l,.,‘ T.__.47- B _‘/3 “B,” w W. 1% 1. 71 wgw mW a ww” Z? w”; HwT% .2%, Min? E7 _o 000 0//0o aura U Z j ,0w n. . ,0 \/9 .-. _. E M _ / “ N0 ~ .1. 4 0 m mmm. F212;‘, 1%! 591.1%,1542/12202 air BYBe/n M ATTORNEY 2,130,706 Patented Sept. 20, 1938 ‘UNITED STATES PATENT OFFICE 2,130,706 ELECTRICAL SWITCHING DEVICE Hubert Mackenzie Salmond, Fareham, England, v assignor to Graviner Manufacturing Company Limited, London, England Application July 2, 1934, Serial No. 733,520 In Great Britain July 28, 1933 '17 Claims. (01. 200-52) This invention relates to electrical switching devices of the kind in which a pendulum controls the operation of the switch contact elements. ’ An object of the invention is to provide an electrical switching device for use upon vehicles and crafts in which the switch contact elements are actuated by a comparatively powerful spring under control of a pendulum subject only to small reaction. Another object of the invention is to provide a 10 switching device in which the switch contact ele ments are actuated by a spring operated member interconnected to a pendulum by a pivotally .mounted lever element. A still further object of the invention is to 15 line H-ll of Fig. 10, showing details of the switch mechanism, and 1 5 Fig. 13 is a detail of the arcuate sector cam which engages the pendulum cam. Referring to Figure 1 of the drawings, numeral 2 represents a pivotally mounted pendulum com prising a mass 3 and a mushroom shaped head 10 in a vehicle or craft in an accident. With these and other objects in view, the in vention will be better understood from the fol a contact adapted to be engaged by a similar con- 20 lowing detailed description taken in connection with the accompanying drawings wherein: Figure 1 shows an electrical switch controlled by a pendulum together with a diagrammatic representation of a circuit controlled by the switch. ~ ,Figure 2 shows a slightly di?erent form of switch mechanism to that shown in Figure 1. Figure 3 shows a mechanism in which the pen 30 dulum is of a di?erent form from that shown in Figures 1 and 2. i ' . Figures 4 and 4a show arrangements of mecha nism employing a multiple catch arrangement in side elevation and front view. Figures 5 and 5a show a still further modi?ca tion of a pendulum device. Figures 6 and 6a show respectively side eleva further rigid contact element II is provided with tact carried by another leaf spring l2. The switch is so arranged that it is adapted to be operated by a leaf spring I3, su?lciently power ful to actuate springs l0 and II, but normally en gaged by the toe H of a lever device [5 carrying 25 at its other end a member l6 adapted to engage head 4. The lever 15 is pivotally mounted at I1 and is provided with a heel IS, the arrangement being such that spring I3 is normally retained in ‘ the position indicated in Figure 1, but is re- 30 leased when the mass 3 of the pendulum is dis placed, for example, due to the tilting of the mechanism or as a result'oi exceedingly violent impact. When spring I3 is released it opens the nor- 35 device arranged to be locked in operated and mally closed contact points carried by elements 9 and I0 and closes the contact carried by elements II and I2 and the switch remains in this posi tion until operating handle I9 is pressed down non-operated‘ positions. wardly to a su?lcient extent to force the end of 40 Figures 7 and 7a show respectively side view and front elevation of an instrument com prising a pendulum controlled switch device spring I; into engagement with the heel ll of lever l5, whereby the element [6 is'lifted clear of head 4 so that pendulum 2 can assume its normal mounted in a protecting case. position indicated in Figure 1. tion and front view of a mechanismland switch ' electrical supply resources on a vehicle or craft switch ‘mechanism in unset position, with igni which sources comprise battery 20 and generator 2!. Normally one lead is taken from the battery line Il-Il of Fig. 8, showing the switch spring contact elements, and operating cams and levers.‘ Fig. 10 is a vertical sectional view similar to Fig. 8, with the switch mechanism set and the ignition circuit closed. 45' Figure 1 shows how the switch controls the vFig. 8 is a vertical sectional view of my device taken on the line Ill-40 of Fig. 9, showing the tion circuit open. Fig. 9 is a vertical sectional view taken on the 65 v Fig. 12 is a horizontal sectional view taken on l, the pendulum being mounted by means of a ball 5 supported in a socket device 6 carried by bracket 1 itself secured to a mounting plate 8 of the device. The switch mechanism comprises a rigid con- 15 tact element 9 provided with a current conducting contact engaging a similar contact carried by the leaf spring contact element I0. In addition a provide an automatically operable switching de vice adapted to disconnect all electrical circuits 40 Fig. 11 is a vertical section taken on the line iii-13 of Fig. 10. output terminal to the electrical system on a 50 \ vehicle including the lamps and ignition coil as. well as various electrically operated devices. This lead is cut and connected to a connector 22 itself connected by leads to normally closed con tacts 9 and III in such a manner that all cur- 55 2 ensures rents supplied by battery ‘(it except to the self such that the pendulums when rotating angularly do not effect appreciable movement of lever l5, starter flow over the normally closed contacts. The generator 2| has its output terminal con nected to one of elements it or 112, the other be ing connected to earth or to the other terminal of the generator, the arrangement being such that when spring l3 operates spring contacts ill and N2, the generator is short circuited. As will be noted the lever 35 is provided with 10 toe and heel parts l4 and it so arranged that the spring it engages the lever in a plane parallel and closely adjacent to that through the center of the lever l5 so that, although the tension of spring it may be quite considerable, the force supplied by element 55 to the head 4 of the pendulum i’ is comparatively small. Referring to Figure 2, the lever i5 controls a knife blade switch comprising blade 23 and ?xed contacts 24, a projecting catch 25 being en~ 20 gaged by toe M of the lever l5, a helical spring 28 actuating the switch and a projecting mem ber 2i serving to reset the mechanism after actua tion as a result of an accident or the like. but the shape of cam and cam 45 is such that when the pendulums move in a forward direc tion, a movement against the action of the switch actuating springs is effected and the angles of these cam elements are so arranged that the pendulums do not release unless the device is subject to impact of considerable violence. In Figures 5 and 5a is shown a modi?ed form 10 of the pendulum comprising a mass 48 carried by arms re supported by a pivot support 55, the arms .orming a cam 5i adapted to engage the elemen it of lever l5, the arrangement be ing such that upon sldeway angular displace ment of the pendulum the element I6 is released from the cam 5i when the angle of displacement attains 'a predetermined value and in the case of impact in a longitudinal direction the mass rill swings forward or backwards whereby ele ment i5 is again released from 'cam 5| thus en abling lever iii to release the switch controlling element. Referring to Figure 3, this figure shows a In Figures 6 and 6a is shown a form of mecha slightly differently shaped lever l5 and an operat nism in which means are provided for operating ing member 28 actuated by a helical spring the contact assembly so as to disable the elec adapted to actuate a contact assembly substan ' trical system upon a vehicle by means such as a tially as indicated in Figure 1. The pendulum key the device thus being capable of preventing device shown in Figure 3 however, differs sub unauthorized operation of a vehicle. 30 stantially from that described in Figures 1 and The pendulum and lever arrangement are prac 2 and comprises a cam device 25 carried ‘by *arms 38 pivotally mounted ‘at 86 upon a collar or the like 32, itself mounted to pivot or rotate upon a pin or the like 38. The element l6 of lever l5 normally rests upon cam 29 and if the device is turned sideways the cam will move away from element it whereby the lever will be released when the pendulum attains a predetermined angular displacement depending upon the length 40 of cam 29. _ In the case where the mechanism shown in Figure 3 may be subject to impact in a forward direction the cam 29 will move forward in a forward direction causing release of the lever l5, with resultant operation of the switch. The contactor 28 is mounted upon a spindle provided with hand operated means so that upon rotation against the action of the operating heli cal spring the catch 28“ will engage heel ill of lever l5 and bring element l6 into a position in which the pendulum and cam 29 assume the normal position indicated in Figure 3. In Figure 4, is shown a modi?cation of the lever arrangement in which toe M of lever I5 does not engage the switch controlling element directly but engages the long arm 35 of a lever 36 hav ing a toe 31 engaging the switch controlling ele ment 38, a heel 39 being provided upon lever 36 for effecting restoration to normal of the mecha 60 nism. The switching device comprises a rotatably mounted drum 40 provided with conducting seg ments 4| and a contacting brush element 42. The switch may be arranged to open or close the cir cuit as desired but the drum is actuated by a 65 helical spring 43. The pendulum device takes the form of a ?ail 44 and lever I5 is pro vided with a cam 45 engaging a cam shaped por tion 46 upon pendulum 44. The pendulum is ‘pivotally mounted at 4'!11 upon a stud or the like 70 41 itself rotatably mounted in a supporting plate or the like 8. I As ‘will be observed, the point of engagement between lever l5 and the pendulum of Figures 3 and 4 is vertically below the point of support of 75 the pendulum. The shape of cams 29 and» 45 is 20 30 tically identical to those described in connec tion with the previously described ?gures, and the contact assembly is that shown in Figure 1 except that spring i3 is mounted adjacent the spring assembly and is adapted to eiTect actuation ‘ thereof by an extension i311. The means for actuating the switch assembly comprises a rotat ably mounted shaft 52 provided with a project ing arm 58 adapted to operate springs l8 and it’ when the shaft is rotated in an anti-clockwise 40 direction. A further arm 54 carried by the shaft serves to engage spring it to restore the same into set position in engagement with the toe 3'! of lever 36. In order to ensure correct positioning of the shaft 52, a cam 55 is mounted thereon and is adapted to be engaged by a spring 56 secured to the mounting plate 8 of the instrument. When the cam is shaped as shown the shaft has two normal positions of 90° angular displace merit, and inthe normally set position the arms . 50 53 and 54 are so disposed that they vdo not pre vent operation of the device in case the lever l5 should be released by the pendulum. The shaft 52 may be mounted by bracket ele ments ?xed on the plate 8 and provided with tu bular extensions 51 housing split sockets 58 to which the shaft 52 is secured. In order to pre vent unauthorized operation of shaft 52 a spring 59 mounted upon tubular extensions 51 is adapt~ 60 ed to engage the slot in sockets 58 from which it must be ejected by means of a key 60 which may have‘slots provided therein adapted to engage pins disposed in the _slot in sockets 58 so as to prevent insertion of- keys other than those in - tended to operate the mechanism. The tubular extension 5‘! and socket 58 terminates against the side of the enclosing casing or cover for the mechanism through which the key hole is ac~ cessible and to operate the mechanism by means 70 of the key this is inserted into the keyhole and forced in so as to lift the spring 59, after which the key and shaft 52 can be turned until spring 56 drops into engagement with the appropriate indent'in cam 55 in which position the springs 3 I0 and I2 open the battery circuit of the car and short circuit the dynamo and disable the high tension system. A spring 6| also mounted upon tubular exten sion 51 is adapted to engage the slot in the socket 58 when this has been rotated 90°, and upon withdrawal of the key this spring locks the shaft 52 and the switch mechanism in the operated position. Figures 7 and ‘70 show a practical embodiment of the invention in which a switch mechanism comprising a contact assembly and automatically operable release mechanism is mounted in a pro tective casing so as to be capable of being mount 15 ed .for example under the bonnet of a motor car. Electrical leads'are provided from the instrument ‘to the battery and dynamo as well as to the high tension magneto if such is provided upon a car, and an additional earth connection is provided 20 from the instrument to effect the appropriate circuit changes. . Referring ‘to Figure 7, numeral ‘III indicates the bottom of a protective casing, ‘ll being the top thereof capable of being secured to the bot tom in any suitable manner. The mechanism of the instrument is mounted upon a mounting plate 13 carried by a suitable number of posts 14 securedto the casing bottom 18. The pendu lum 15 is provided with a central cam surface $0 16 and is suspended from a support TI by means of extending lugs which engage a pin 18 mounted in support ‘I1 in such a manner the pendulum The insulating sleeve on stud 95 permits spring 98 to close its contact with the contact upon element 9|v and subsequently the spring 94 is forced away from engagement with contact 92 whereby the circuit over these contacts is opened. _When the instrument of the present invention is employed upon a vehicle, electrical leads are takenfrom the battery so that all the current supplied by the battery to the electrical system except the self-starter is normally flowing over 10 contacts 92 and 94. Contact 9| is connected to the dynamo output terminal and contact 93 is connected to the instrument which is connected to earth. When the instrument operates it will be observed that contacts 9! and 93 close before 15 contacts 92 and 94 are opened, this has been found desirable in practice as the dynamo is disabled before the battery circuit is open, whereas liability to damage the electrical devices and lamps exists if the battery circuit is opened before the dynamo is put out of action. When the instrument is employed upon a ve hicle it is mounted so that the pendulum hangs vertically downwards, centrally over cam 80, and when the vehicle is overturned or when it at— tains an angle of approximately 45° the cam 18 disengages cam 88, and, as a result of the action of spring 90, lever 84 turns in an anticlockwise direction as shown in Figure 7 due to the dis engagement of toe 85 with cam 81, and lever 8| 30 turns in a clockwise direction due to the disen gagement of the long arm of lever 84 with toe is free to swing in planes at right angles to plate 82, and as soon as cam 18 releases cam 88 the 13. The support 11 is carried by a stud 19 fixed to plate 13 in such a manner that it is capable of rotation in a plane parallel to plate 13. The lever 8| releases lever 84 and this therefore re cam ‘I6 engages a triangular are shaped cam 88 carried by lever 8| pivotally mounted by pin and bracket means upon plate 13. Lever 8| is pro 40 vided with toe 82 and heel 83 which are engaged by the long arm of a lever device 84 pivotally - mounted by pin and bracket means on plate 13. The lever 84 is provided with toe 85 and heel '86 adapted to engage a cam device 81 fixed upon 45 a spindle 88 mounted by a pair of brackets upon plate ‘I8 so as to be capable of rotation but ?xed against endway displacement, a resetting handle 89 being secured to an extension of shaft 88 pro jecting through the protective casing. A helical spring 98 is carried by shaft 88 and arranged to rotate the shaft in a clockwise direction when cam 81 is released by lever 85. The contact as~ sembly comprises ?xed contact elements 9| and 92 and spring contacts 98 and 94. The cam 81 is provided with a projecting stud or pin 95 car rying an insulating sleeve adapted to engage spring contacts 93 and 94, the arrangement be ing such that spring 98 is held in, a normally open position as shown in Figure '7, but upon release of cam 81 by lever 84 the stud 95 is rotated until it engages a stop 96 which is connected to a terminal which in its turn may be connected to the high tension magneto if such is employed upon av vehicle or craft whereby the same is switched off when the instrument operates. Stop 96 is insulatingly supported from mount ing plate ‘I3 and is provided with binding post H3.v The‘ contact assembly is supported by a stud “4 attached to mounting plate 13. The 70 stud H4 is advantageously of metal and forms 'part of the switch ‘circuit, and is electrically connected to mounting plate 13. Binding post I28 is attached to stud H4. Shaft 88 is jour nalled in a pair of spaced supporting plates H8, 76 “1, which are attached to mounting plate 18.‘, leases cam 81 which is rotated so as to effect closure of springs 9| and 93 and opening of con tacts 92 and 94 before coming into contact with the stop 96 whereby this element is connected to earth. The radius of the cam 80 may be struck from the center of pin 19 so that no movement 40 of lever 8i is produced when the pendulum ro tates in a plane parallel to plate 13. Alter natively, the radius may be struck from slightly above the center of pin 19 in which case a slight lift of the cam 88 and lever 8|, against the action 45 of spring 90, is produced when the pendulum is displaced from its normal central position and this arrangement tends to retain the pendulum in a central position. In the case where a vehicle is subject to impact, ' the pendulum 15 moves forward owing to its inertia and cam 16 is caused to lift cam 80 and the long arm of lever 8| against the action of spring 99 to a predetermined extent so as to pre vent release in ‘case of a minor impact, for ex 55 ample, when the ‘brakes of a vehicle are suddenly applied or when a slight impact with another vehicle or an obstacle takes place which is not likely to cause serious injury to the driver or damage to the vehicle. The inclination of the 60 cam 18 is however, such that in the case of a violent impact release of lever 8| takes place without fail. The inclination of carn~16 as indi cated in Figure 7, is 45° and this has been found to be suitable for practical purposes, 65 The casing comprising parts 18 and ‘II is adapt ed to be mounted upon a'vehicle, for example, under the bonnet, and, to facilitate mounting,v a pair of lugs or the like I I8, I I9 are secured to the casing bottom whereby the instrument may be 70 secured in a horizontal position with the part ‘II of the'casing pointing in the direction of travel of the vehicle. ' _ Electrical leads I00 soldered or sweated to tags 9.8 upon the contact assembly and secured by 75 4 arsavoe clamping devices 99 to the bottom of the casing are provided for connection to the electrical system upon a vehicle or craft. In the case of switch devices for use on aero planes it is desirable that cams 45 and 80 are shaped somewhat as indicated in dotted lines in Figure 4a so as to tend to retain the pendulum in normal position although the instrument is turned sideways or upside down. In order to en 10 able the mechanism to be reset, helical springs 840 and till may be provided upon the pivot spindles of levers 34 and ill, Figure 7, tending of an abrupt acceleration or deceleration of the vehicle, and manually operable latch-resetting means for reclosing said electrical contact ele ments. 4. A switch for controlling the electrical cir cuits of a vehicle upon a condition of collision or the like, comprising: a plurality of electrical contact elements, means for normally maintain ing at least one pair of said contact elements in closed-circuit relationship, means for normally maintaining another pair of said contact ele ments in open-circuit relationship, means effec to rotate the same in a direction to effect dis engagement, also a helical spring ‘lélll or the like 15 may be attached to the pendulum ‘l5 so as to tend to retain the same in its normal position, tive to oppose and overcome each of said two last-mentioned means and invert the normal con the spring being capable of su?icient extension lum means associated with said latch means and effective to release said latch means upon the oc currence of an abrupt acceleration or decelera ‘to e?ect release in case of impact. When a spring 7130 is attached to pendulum 715, the cam 30 may 20 be shaped as shown in Figure 7a as the spring prevents disengagement between cams l6 and 80) except in the case of violent impact. It is of course to be understood that the various parts of tact positions, latch means for rendering said contact-inverting means ineffective, and pendu tion of the vehicle. . 20 5. An electrical switching device for rendering inoperative the electrical circuit of a vehicle upon a condition of collision or the like, comprising a the device may be designed and constructed in _ plurality of electrical contact elements, a spring various other ways, and the various mechanisms arranged in other combinations than illustrated, and therefore I do not wish to be limited in any manner except as set forth in the following claims. 30 Having thus fully described my invention, what I claim as new and desire to protect by Letters Patent is: 1. A switch for rendering inoperative the elec trical circuits of a vehicle upon a condition of 35 collision or the like, comprising: a plurality of electrical contact elements, spring-biased means for maintaining said contact elements in contact under normal conditions, spring means effective to oppose and overcome said last-mentioned 40 means to open said contact elements, latch means for maintaining said last spring means retracted and‘inoperative, pendulum means associated-with said latch means and eiiective to release the same upon the occurrence of an abrupt accelera tion or deceleration of the vehicle, said spring means being provided with a manual positive con trol operable with a single movement to reset said contact elements in closed position when said pendulum means has returned to normal posi tion. 2. A switch for rendering inoperative the elec trical circuits of a vehicle upon a condition of collision or the like, comprising: a plurality of electrical contact elements, means for maintain 55 ing said contact elements in contact under nor 60 65 70 76. mal conditions, means e?ective to overcome said last mentioned means and open said contact ele~ ments, latch means for rendering said contact opening means inoperative, and pendulum means having a cam element normally in positive lock ring abutment with said latch means but dis placeable to release said latch-,means upon a swinging of the pendulum occasioned by an abrupt acceleration or deceleration of the vehicle. 3. A switch for rendering inoperative the elec trical circuits of a vehicle upon a condition of collision or the like, comprising: a plurality of electrical contact elements, means for maintain ing said contact elements in contact under nor~ mal conditions, means effective to overcome said last-mentioned means and open said contact ele ments, latcn means for rendering said contact opening means inoperative, pendulum means as sociated with said latch means and e?ective to completely release the same upon the occurrence actuated member electrically independent of said 25 contact elements for actuating said contact ele ments, a lever, a pivotal support for said lever, said pivotal support being attached to said lever at a point along the length thereof to divide said lever into two sections of uneven length, means formed in the shorter of the two sections of said lever for engaging said spring member and hold .ing said member under tension, means engaging the free end of the other of said sections for trip ping said lever and releasing said spring for actu 35 at'ing said contact elements and pendulum means for controlling said last means. 6. An electrical switching device for rendering , inoperative the electrical circuit of a vehicle upon a condition of collision or the like, compris 40 ing a plurality of electrical contact elements, a spring member electrically independent of said‘ contact elements for actuating said contact ele ments, a lever, a pivotal support for said lever, means at one end of said lever for engaging and holding said spring under tension, means engag ing the other end of said lever for tripping said lever and releasing said spring for actuating said contact elements, ‘pendulum means for control ling said last means and resetting means for re setting said lever after it is tripped. 7. An electrical switching device for rendering inoperative the electrical circuits of a vehicle upon a condition of collision or the like, com prising a plurality of electrical contact elements, 55 a spring member electrically independent of said contact elements for actuating said contact ele ments, a lever including catch means for holding said spring member in a predetermined position, means associated with said contact elements for 60 engaging said spring member when the latter is released by said catch means, pendulum means for engaging said lever to release said catch means from said spring for actuating said con— tact and resetting means for resetting said lever after it is released. . , 8. A switch for effecting changes of the elec trical circuits upon vehicles and craft upon a con dition of impact, comprising a vfreely suspended pendulum, supporting means comprising a pair " of independent pivots for pivotally supporting said pendulum with two degrees of rotative free dom, a spring urged lever adapted to engage and to damp the movement of said pendulum, con tact elements held in normal position under 2,180,706 spring action, a spring urged member normally held in tensioned position by said pendulum and lever and adapted when released upon occur rence of impact to actuate said contact elements to eifect desired circuit changes and manually operable resetting means for resetting said lever after it is released. , 9. An electrical switching device for rendering inoperative the electrical circuits of a vehicle 10 upon a condition of collision or the like, compris ing: a panel member, a pendulum' pivotally sup ported on said panel member, a ?rst lever also pivotally supported on said panel, means at tached to said ?rst lever for slidably engaging 15 said pendulum, said ?rst lever having a ?rst latch device, a second lever pivoted with respect to said ?rst lever and having an end engageable with said ?rst latch device of said ?rst lever, a rotatable shaft, a spring attached to said shaft, said second 20 lever having a second latch device, means on said 5 for maintaining said switch mechanism in actu-~ ated position, a cam having cooperating means engageable with said latch mechanism for lock ing the same, a pendulum having a cam surface engageable with said cam, and supporting means comprising a pair of independent pivots for piv otally supporting said pendulum with two de grees of rotative freedom, whereby movement of predetermined amplitude of said pendulum beyond cam engaging position unlocks said latch 10 mechanism‘and releases said switch mechanism. 15. In a crash actuatable safety switch, a switch mechanism, actuating means for opening and closing said switch mechanism and compris ing a spring normally maintaining said switch 15 mechanism in a released position and further comprising latch engaging means, a latch mech anism engageable with said latch engaging means for maintaining said switch mechanism in actu ated position, a cam having cooperating means 20 shaft for engaging said second latch device of engageable with said latch mechanism for look said second lever when said shaft is rotated against said spring, an electrical contact device, and means for actuating ‘said electrical contact 25 device when said shaft and said levers are re leased by movement of said pendulum so that ing the same, a pendulum having a cam sur said ‘shaft is rotated by the action of said spring. 10. An electrical switching device for rendering inoperative the electrical circuits of a vehicle 30 upon a condition of collision or the like, compris ing: a rotatable shaft, a spring attached to said shaft to prevent the rotation of said shaft ex cept with or against the tension of said spring, electrical contacts positioned to be actuated upon the rotation of said shaft, a lever and latch de vice, means cooperating with said shaft for en gaging said lever and latch device when said shaft is turned against thetension of said spring to hold said shaft in this tensioned position, a 40 camv attached to said lever and latch device, and a pendulum having means for engaging said cam to hold said shaft in said tensioned position until a condition of collision or the like disen gages said cam from said pendulum means. 45 11. An electrical switching device as set forth in claim 9 including manually operable means .for said shaft to reset the switching device after the switching device has been actuated. face engageable with said cam, said cam having its periphery engageable with said pendulum cam surface substantially'in the form of a circular 25 arc, and a pivot for supporting said pendulum for movement substantially parallel to the plane of said arc, said ‘are being substantially struck about _ said pivot as a center, whereby movement of pre determined amplitude of said pendulum beyond 30 cam engaging position unlockssaid latch mech anism and releases said switch mechanism. 16. In a crash actuatable safety switch, a switch mechanism, actuating means for opening and closing said switch mechanism and compris 35 ing a spring normally maintaining said switch mechanism in 9. released position and further comprising latch engaging means, a latch mech anism engageable with said latch engaging means for maintaining said switch mechanism in ac 40 tuated position, a cam having cooperating means engageable with said latch mechanism for lock ing the same, a pendulum having a cam surface engageable with said cam, said cam having its periphery engageable with said pendulum cam 45 surface in the form‘ of a circular arc, said pen dulum cam surface being recessed in a direction substantially perpendicular to the plane of said 12. An electrical switching device as set forth ‘ arc, and a pair of mutually perpendicular co 50 in claim 10 including manually operable means _ operating pivots for supporting said pendulum 50 attached to said shaft to reset the switching de vice after the switching device has been actuated. 13. In a crash actuatable safety switch, a switch mechanism, actuating means for opening 55 and closing said switch mechanism and compris ing a spring normally maintaining said switch mechanism in a released position and further comprising latch engaging means, a latch mech anism engageable with said latch engaging means for maintaining said switch mechanism in actu ated position, a cam having cooperating means engageable with said latch mechanism for lock ing the same, and a pendulum having a cam sur face engageable with said cam, whereby move 65 ment of predetermined amplitude of said pendu for movement substantially respectively perpen dicular and parallel to the plane of said are, said are being. substantially struck about a center in said pivot about which said pendulum moves par allel to the plane of said are, whereby movement 65 of predetermined amplitude of‘ said pendulum beyond cam engaging position unlocks said latch mechanism and releases said switch mechanism.‘ 17. 'In a crash actuatable safety switch, a switch mechanism, actuating means for opening 60 and closing said switch mechanism and compris ing a spring normally maintaining said switch mechanism in a released position and further comprising latch engaging means, a latch mech anism engageable with said latch engaging means 65 lum beyond cam engaging position unlocks said . for maintaining said switch mechanism in actu ated position, a cam having cooperating means latch mechanism and releases said switch mech anism. ' 14. In a crash actuatable safety switch, a 70 switch mechanism, actuating means for opening and closing said switch mechanism and compris ing a spring normally maintaining said switch mechanism in a released position and further comprising latch engaging means, a latch mech 75 anism engageable with said latch engaging means engageable with said latch mechanism for lock ing the same, a pendulum having’ a cam surface engageable with said cam, said cam havingv its 70 periphery engageable with said pendulum cam surface in the form of a circular arc,'said pendu— lum cam surface .‘being recessed, in ya direction substantially perpendicular to the plane, of said ' ' arc, and a pair of mutually perpendicular cooper ating pivots for supporting said pendulum ‘.lor the point where said cam arc meets said cam movement substantially respectively perpendicu surface when said pendulum is in normal posi~ lei‘ and parallel to the plane of said are, said are being substantially struck about a center in said pivot about which said pendulum moves parallel to the plane of said are, pivot about which said pendulum moves perpendicular to the plates‘ of said. are being positioned substantially above tion, whereby movement of predetermined am- ' plltude of said pendulum beyond cam engaging positlon unlocks said latch mechanism and re» leases said switch mechanism. HUBERT MACKENZIE SALMOND.