Патент USA US2408902код для вставки
Oct. 8, 1946'. A. ARNOT 2,408,901 ELECTRIC SWITCH vSENSI'I'IVE TO S-MALL OPERATING MOVEMENTS Filed April 30. 1943' 1 “:EIEit .a. i 2,408,901 Patented Gct. 8, 1946 UNITED STATES PATENT OFFICE 2,408,901 ELECTREC SWITCH SENSITIVETO- SMALL OPERATING MOVEMENTS Alf-red Arnot', Warrington, England, assignor to Aeronautical & Mechanical Investments» Lim ited; a British company Application April 30, 1943, Serial No. 485,220 In Great Britain April 23, 1942 2 Glaims. (Q1. 200-153) 1 This invention comprises improvements in or relating to electric switches sensitive to small op erating movements. It is an object of this invention to provide an electrical switch mechanism‘ which is sensitive to very’ small movements of the operating mem ber. For example in the mechanism described in patent application No; 469,270, which comprises an electrical device for transmitting movement from a transmitter to a receiver such a switch 1O mechanism is called for, and maybe necessary both at the transmitter and‘ at the receiver. According to the present invention an- electric switch mechanism comprises in combination‘ a base, a contact-carrier pivotally mounted on the base and having a pallet-face in a plane to one side of the pivotal axis and facing away‘ there from, a switch contact-member operatively con nected to the contact-carrier so as to be oper 2. The switch mechanism comprises an operating spindle II‘ which is rotatably mounted and car ries at one end a head l2 containing a transverse spring plunger [8 which constitutes a switch-ac tuating member, projects from one side of the head and has a knife edge ill, the» line of which extends in a direction parallel with the aXis of the operating spindle ll. Concentric with the spindle H and surrounding it, but mounted-for independent rotation, is a circular switch base l5 of metal and on the switch base there is pivoted on a post l6, close to the» spring plunger l3‘, a contact-carrier H in‘ the form of-v an oblong block of metal having a pallet face 18 which engagesthe knife edge 14 on the spring plunger I3‘; The pallet-iace 18 in its neutral position is at right anglesto the line-of'pressureof the-spring plunger l3, the axis of- the pivot-post IQ of the contact carrier being in this positionv intersected; by- the line of pressure‘ of- the-spring plunger it‘ through ated when the contact-carrier rotates about its 20 the knife edge M». The contact-carrier has a aXis, and an actuating-member having a pallet V groove 19» cut in- one end and on the» rotatable engaging portion which is mounted so as to be switch base there is an upstanding» block 28 hav yieldingly pressed on the pallet face and to be ing another V groove 2 li which faces the V groove: so movable that the line of pressure can be shifted H! in the contact-carrier. Between the two V to one side of the contact-carrier pivot to actuate grooves there extends a piece of ?at-section: the contact-member inv one direction, and to be spring-steel 22» which is of curved or sinuous for-‘ returned to return the contact-member‘ mation so that it constitutes a» somewhat stiff The actuating-member may be capable of being compression spring‘, and thelocation of the parts centered so that its-line of pressure passes through the pivot axis and of being moved to either side 30 is such‘ that when‘ the contact-carrier Hi is in its mid position with the line of pressure of. the to move the contact-member correspondingly, spring plunger 13 intersecting the axis. N3 of the and the contact-member may engage two con pivot the spring 22 which extends between the V tacts, one when moved to one side and the other grooves has a line of pressure which also inter when moved to the other. Thus it is possible to sects the axis it of the pivot. The spring 22 is make the switch member operate as a two-way thus a toggle spring, and while it does not prevent switch with a neutral or off position in the centre, the spring plunger l3 from holding the contact if desired, although it is within the scope of the carrier ll at rest in its central or normal posi invention to use the switch member for closing tion, it assists in pushing the contact-carrier over a single contact only. Preferably the contact-carrier is further con 40 to one or other of its extreme positions immedi ately the spring plunger of the operating member trolled by a spring mounted on the base in such a is moved so that it presses either to one side or to position as to act as a toggle-spring and thus to the other of the aXis of the contact-carrier IT. increase the certainty of movement of the con From the other end of the contact-carrier I‘! tact-member into contact-engaging position. there extends a spring arm‘23 which constitutes The following is a description, by way of ex a contact-member and terminates in a double ample, of one construction of switch mechanism sided contact 24. The contact 24 plays between in accordance with the invention: two ?xed insulated contact posts 25, 26 on the In the accompanying drawing, switch base. A bridge-piece 21 carries a bearing Figure 1 is a front elevation of an electric for the end of spindle ll. switch mechanism according to this invention; Therefore if the parts are in their normal po Figure 2 is a plan; sition the axis of the spring plunger l3 of the Figure 3 is a diagrammatic perspective view of operating spindle will intersect the pivot l6 of the switch mechanism and of one possible ar the contact-carrier H and the switch contact 24 rangement of parts and connections for auto 55 will be held centrally between the two ?xed con matic servo-operation. 2,408,901 4 tacts 25, 26, without touching either of them. this will be attained. Stability may be further A very small angular de?ection of the operating spindle I I in either direction will cause the line of pressure to be altered and the switch contact increased, at the expense of sensitivity, by slightly ?attening the knife edge. It will be appreciated that while a rotatable actuating member and rotatable switch base have been described the invention is applicable to other will be brought ?rmly into engagement with one or the other of the contacts 25, 26 on the rotat able sWitch base. If such a swtich mechanism cases, for example where the switch base is ?xed, is employed in apparatus of the kind described in the aforesaid patent application No. 469,270 the operating spindle ll of the switch may con or where one part (such as the actuating mem ber) moves in a straight line relatively to the other part (such as the base) instead of being stitute the control shaft on the receiver, as shown in Figure 3, and the switch base I5 may be con nected to a follower shaft 28, by means of the bridge piece 21 or otherwise. This mechanism thus takes the place of the cam-closed switch contacts described in the aforesaid specification. In Figure 3 the parts are similar to Figures 1 and 2 but the base 15 is shown as having gear teeth around its edge meshing with a pinion 29 on a shaft 30 of a reversible motor 3|. rotatably mounted. I claim: 1. An electric switch mechanism comprising a base, a pivoted contact-carrier mounted on the base and having a pallet-face in a plane to one side of the pivotal axis and facing away there from, a switch contact-member carried by the contact-carrier so as to be operated when the contact-carrier rotates about its axis, an actu The shaft ‘ H_ is operated in either direction ‘by magnetic pawl-operating devices the pawls of which oper press said pallet-engaging portion against the pallet-face of said contact-carrier, said actuating ate a ratchet wheel 32. The motor is connected by line 33 to a source of electric power 34 and by lines 35, 36 to the contact posts 25, 2B. The con- tact 24 is connected by line 3'! to the other ter minal of supply. Thus when contact 24 is closed against 25 the motor 3! will operate in one di rection and when closed against contact 26 the motor will operate in the other direction. The directions of movement are arranged to be such that the base l5 always tries to follow the shaft H and thus shaft 28 is motor-driven to the same extent of movement as shaft I l. The motor may be such as the one described in British patent application No. 6373/ 41. The switch may also be used in a transmitter ating member having a portion movable towards the pivot of the contact-carrier and means to ~ member being mounted so that its line of pres sure passes through the axes of said pivot and is capable of movement to either side to move the contact-carried correspondingly, a pair of contacts adapted to be alternatively engaged by said contact-member depending on its direction of movement so that the contact member may act as a two-Way switch member with a central neutral position, and a spring mounted on the base and engaging the contact-carrier in such a position as to act as a toggle-spring and thus to increase the certainty of movement of the con tact-member. 2. An electric switch mechanism comprising in combination a rotatably mounted base, a contact carrier pivoted on said base eccentrically to the tion N 0. 469,270, where the transmitter has a con 40 center of rotation thereof and having a pallet trol‘ shaft carrying spring contact arms. iace facing towards the center of rotation of the In the mechanism herein described it is nec base, a switch contact-arm extending from said essary that the spring loading behind the knife contact-carrier, a contact on the base engageable edged plunger I3 on the operating spindle II by said contact-arm, a rotatable actuating mem should be great enough to ensure that the mech ber coaxial with the base, a pallet-engaging por anism will re-set to neutral position, that is to tion on the actuating member movable radially say with the switch contact 24 out of engagement outward into contact with said pallet-face, resil with either of the contacts 25, 26 on the switch ient means for urging the pa1let~engaging mem base, after it; has been displaced, when the op ber toward said pallet-face, and a toggle compres erating spindle regains the position in which the ' sion spring mounted on said base and engaging plunger is in line with the axis of the contact said contact-carrier. mechanism of the kind described in the alterna tive form of apparatus in the aforesaid speci?ca carrier. If the spring loading is su?iciently great ALFRED ARNOT.