US2351236A - Electric switch - Google Patents

Description

June 13, 1944. G. SMILEY ETAL 2,351,236

ELECTRIC swI'rcH Filed July 10, 1942 1 .79 iii 4/ Patented June 13, 1944 ELECTRIC SWITCH Gilbert Smiley, Bingham, and Chauncey L. Delano, Waltha m, Mass assignors to General Control Company, Cambridge, Mass, a corporation of Massachusetts Application July 10, 1942, Serial No. 450,398

12 Claims.

This invention relates to electric switches and more particularly switches of the so-called telephone type adapted to be mounted in a switchboard panel with nothing but the handle or key projecting from the face of the board, each switch comprislnga frame, a contact block, a plurality of groups of contact springs mounted on the block and an actuator for operating the contacts.

Objects of the present invention are to provide a switch which is simple and economical to manufacture, which is durable and reliable in use, which can be readily converted from a locking type in which the key remains in operative position until returned to neutral position to the non-locking type in which the key remains in operative position only so long as it is held in that position by hand, which has a long life, which electrostatically shields opposite groups of contacts from each other, which is self-aligning in the process of assembling the parts together, and which is generally superior to prior switches of the character referred to.

In one aspect the invention involves a frame having a supporting wall with a group of spring contacts mounted on one side of the wall and an actuator movably mounted on the other side of the wall, the actuator having a roller or other operator extending through an opening in the wall for operating the contacts, and a spring detent mounted on the first side of the wall for engagement with the actuator through an opening in the wall yieldingly to hold the actuator in one or more of the positions to which it is moved.

In a more specific aspect the invention involves two walls with a space therebetween for the aforesaid actuator and with a support for switch contacts on both sides of the juxtaposed walls. When employing two frame plates a spring detent is preferably provided on each plate, the two detents pinching the actuator therebetween through openings in the plates. By providing a detent on each side the thrusts oi the two detents tend to counteract each other thereby reducing the friction and wear on the pivot pin of the actuator or other part which controls its path of movement. By making the actuator of variable thickness along the zone engaged by the detents the actuator is yieldingly held in predetermined positions, as for example a neutral central position and an operating position on one or both sides of the neutral position. By providing the detents with rollers for rolling engagement with the actuator the friction is reduced.

thereby making the switch easier to operate and prolonging its life.

In still another aspect the invention involves a frame having two legs with a space therebetween and a contact block fitted into the space with grooves in one or both sides of the block to receive one or both of the legs. The contact block is preferably fastened on the frame by means of a screw or other fastener extending through the block lengthwise of the legs into engagement with the frame. When the frame is in the form of two plates as aforesaid, the plates are held together by the grooves in the contact block, and by making a fairly snug flt between the block and plates the parts are self-aligning when the block is slipped into the slots in the plates.

For the purpose of illustration a typical embodiment of the invention is shown in the accompanying drawing in which Fig. l is a side elevation;

Fig. 2 is an end elevation;

Fig. 3 is a'section on line 3-3 of Fig. 1;

Fig. 4 is a bottom view;

Fig. 5 is 94560151011 on line 5-5 of Fig. 1;

Fig. 6 is a'perspective view of the actuator;

Fig. 7 is a perspective view of one of the spring detents;

Fig. 8 is a side elevation of a slight modification; and

Fig. 9 is a similar view of another modification.

The particular embodiment of the invention chosen for the purpose of illustration comprises two frame plates l and 2 which are offset at 3 so that, with their lower ends abutting each other face to face, the upper ends are separated by a space 4, the tips of the upper ends being bent outwardly to form flanges 6 and 1 for mounting the switch on a switchboard or the like. The upper ends of the plates may be interconnected by rivets 8 and the lower ends may also be riveted together as indicated at 9. Extending upwardly from the bottom edges of the frame plates are slots ll (Figs. 1 and 4) dividing the frame into two legs, and mounted in these slots is a contact block I2, the opposite sides 01' the block having grooves to receive the edges of the slots. From the upper ends of the slots l l to the shoulder 3, the plates are pressed outwardly as indicated at l3 to form opposing grooves which together form a cylindrical socket. After the plates are secured together this socket is threaded to receive a screw H which extends through a vertical opening IS in the block I! and then threads into the socket.

Mounted on the opposite sides of the contact block l2 are four groups 2|, 22', 23 and 24 of contact springs, the springs being held by screws 26 with a layer 21 of insulation on each side of each spring. The heads of the screws seat on a plate 28 and the other ends of the screws are threaded into a plate 29. In the illustration each group of contact springs comprises a central spring which is somewhat longer than the other two springs and which is engageable with either of the other two springs. As shown in the drawing thecenter spring usually contacts with the inner spring when the key is in the central neutral position shown in Figs. 1 and 3 and, when the key is moved to one of its operative positions, the central spring is moved out of contact with the inner spring into contact with the outer spring.

The actuator for operating the contact spring comprises a cam plate 3| which is pivotally mounted in the space 4 by means of a pivot pin 32. The upper edge of the cam plate is provided with a threaded extension 33 to receive the han dle 34. Mounted in opening 36 in the cam plate are tubes which project laterally through the arcuate slots 38 in the plates I and 2. Mounted on'the projecting ends of the tube are rollers 4| for operating the middle springs of the groups, the rollers being held on the tubes by means of screws 42 threaded into the ends of the tubes. The actuator is also provided with an opening 43 (Fig. 1) to receive a stop pin 44 (Fig. 9) for use in the event-that it is desired .to prevent movement of the actuator in one direction (counter-clockwise in Fig. 9). By omitting the pin 44, as in all of the figures except Fig. 9, the key 34 may be thrown either to the right or to the left.

For the purpose of holding the actuator in its central position or in its right or left operating position, the lower end of the plate 3| is shaped so that it is thin in the middle 46 and at the edges 41, but relatively thick in between, the thickness varying gradually from minimum to maximum and vice versa. Mounted on the outside of the lower end of the plate 22 are leaf springs having ears 52 which are secured to the plate by means of the rivets 9. At their lower ends the leaf springs are recessed as indicated at 53 in Fig. '7 to accommodate the raised portions l3 of the plates I and 2. At their upper free ends the leaf springs are provided with opening 54 to accommodate the rollers 56 which rotate on pins 51 seating in the semi-circular recesses 58 above 'and below the opening 54. The leaf springs 5| are shaped to pinch the lower end of the actuator between the rollers 56, the leaf springs substantially meeting the outer faces of the upper ends of the plates 1 and 2 when the rollers 56 engage parts 46 and 41 of minimum thickness and springing outwardly as the rollers ride over the thicker parts of the actuator. Thus the actuator is yieldingly held in the mid-position or in either one of the operative positions.

The plates l and 2 are provided with opposed openings 6| and 62 for use in the event that it is desired to prevent the actuator from moving far enough to the right or left to be held in operative position by the spring detent. Thus Fig. 8 shows a rivet 63 in the opening 62 for limiting the movement of the key 34 to the left. Thus when the key is released it returns to neutral position instead of remaining in the lefthand operative position.

From the foregoing it will be understood that the modification shown in Fig. 8 differs from the a rivet 63 has been mounted in the opening 62;

and the modificationshown in Fig. 9 differs only in that the pin 44 has been mounted in the opening 43 to prevent movement of the key to the left.

From the foregoing it will be evident that by making the frame l2 of metal it electrostatically shields the two groups of contacts 2| and 22 from the two groups 23 and 24, thereby avoiding interference between the currents in the circuits on opposite sides of the switch. By virtue of the double-plate construction a very rigid frame can be made with relatively thin stock. This construction also affords a convenient and effective way of mounting the actuator 3 I, namely by an ordinary rivet so as to be self-centering without providing shoulders on the rivet. -By virtue of the telescope interengagement between the switch block and the frame plates the parts are self-aligning in the process of manufacture and after being assembled the engagement of the edges of the frame plates in the grooves of the switch block I2 serve to hold. the two plates together. The unique construction also permits the parts to be held together by the single screw [4. Moreover both the actuator and the contact block are simple in shape and economical to manufacture. For example, the actuator may be coined and the block may be die cast. By pinching the actuator between two spring dete nts the thrusts of the detents counteract each other and by providing the rollers 56 the friction and wear are minimized. The openings 6| and 62 and the pins or rivets 63 afiord a convenient way of changing a switch from the locking to the non-locking type and vice versa. For example the switches may be carried in stock without pins 63 and then, in those switches to be made nonlocking, pins 63 may be inserted. Likewise the keys may be readily changed from two-way to one-way operation by inserting pins 44 in the openings 43.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

We claim:

1. An electric switch comprising a frame having two juxtaposed plates with a space therebetween, a contact block, a .group of spring contacts mounted on said block outside each plate, an actuator movably mounted in said space, switch operators extending from the actuator through openings in said plates for operating said groups respectively, said plates having op posed slots extending thereinto from corresponding edges, and the contact block being slidably fitted in said slots with grooves to receive the edges of the slots, whereby the block holds the plates together and the plates hold the block in alignment.

2. An electric switch comprising a frame, a contact block on the frame, switch contacts on the block, and an actuator on the frame for operating the contacts, the frame including two juxtaposed plates with opposed slots extending thereinto from-corresponding edges, and the contact block being slidably fitted in said slots with grooves to receive the edges of the slots, whereby the block holds the plates together and the plates hold the block in alignment.

construction of the preceding figures only in that 3. An electric switch comprising a frame, a contact block on the frame, switch contacts on the block, and an actuator on the frame for operating the contacts, the frame including two juxtaposed plates with opposed slots extending thereinto from corresponding edges, and the contact block being slidably fitted in said slots with grooves to receive the edges of the slots, the plates having on their opposing faces registering grooves which are threaded to form a screw socket, and a screw extending through the block and threading into the socket.

4. An electric switch comprising a frame having two legs with a space therebetween, a contact block fitted in said space with grooves to receive said legs, a fastener extending through said block lengthwise of said legs into engagement with the frame for holding the block on the frame, spring contacts mounted on said block with free ends extending along the frame, and an actuator mounted on the frame to operate said contacts.

5. An electric switch comprising a frame in the form of two juxtaposed plates with a space therebetween, an actuator mounted in said space between certain parts of the plates, other portions of the plates having opposed slots, a switch block fitted in said slots with grooves to receive the edges of the slots, a fastener extending through the block lengthwise of the slots into engagement with the frame, switch contacts mounted on the block with free ends extending along the outside of said parts of the plates, and operators extending from said actuator through the plates into engagement with said free ends.

6. An electric switch comprising two juxtaposed plates which are oil'set intermediate their ends to abut each other at their lower ends and provide a space therebetween at their upper ends, said lower ends having registering slots extending upwardly from their bottom edges and opposing grooves extending upwardly from the upper ends of the slots to form a socket which is threaded to receive a screw, a contact block slidably fitted into said slots with grooves on its opposite sides to receive the edges of the slots, a screw extending upwardly through the block and threading into said socket, switch springs mounted on said block with their free ends projecting along said upper ends of the plates, an actuator mounted on a pivot in said space with a handle projecting from the upper open end of the space, and operators projecting laterally from the actuator through openings in said plates for actuating said switch springs.

7. An electric switch comprising two juxtaposed plates which are oiiset intermediate their ends to abut each other at their lower ends and provide a space therebetween at their upper ends, said lower ends having registering slots extendling upwardly from their bottom edges, a contact block mounted on said lower ends of the plates, switch springs mounted on said block with their free ends projecting along said upper ends of the plates, an actuator mounted on a pivot in said space with a handle projecting from the upper open end of the space, operators projecting laterally from the actuator through openings in said plates for actuating said switch springs, the actuator having a retaining portion which varies in thickness along an arc concentric with said pivot, and spring detents engaging opposite sides of the actuator along said are through openings in the plates, thereby yieldingly to retain the actuator in one or more of its positions.

8. An electric switch comprising two juxtaposed plates which are offset intermediate their ends to abut each other at their lower ends and provide a space therebetween at their upper ends, said lower ends having registering slots extending upwardly from their bottom edges, 9. contact block slidably fitted into said slots with a groove to receive edges of the slots, switch springs mounted on said block with their free ends projecting along said upper ends of the plates, an actuator mounted on a pivot in said space with a handle projecting from the upper open end of the-space, operators projecting laterally from the actuator through openings in said plates for actuating said switch springs, the actuator having a retaining portion which varies in thickness along an arc concentric with said pivot, and spring detents engaging opposite sides of the actuator along said arc through openings in the plates, thereby yieldingly to retain the actuator in one or more of its positions.

9. An electric switch comprising two juxtaposed plates which are onset intermediate their ends to abut each other at their lower ends and provide a space therebetween at their upper ends, said lower ends having registering slots extending upwardly from their bottom edges and opposing grooves extending upwardly from the upper ends of the slots to form a socket which is threaded to receive a screw, a contact block slidably fitted into said slots with a groove to receive edges of the slots, a screw extending upwardly through the block and threading into said socket, switch springs mounted on said block with their free ends projecting along said upper ends of the plates, an actuator mounted on a pivot in said space with a handle projecting from the upper open end or the space, operators projecting laterally from the actuator through openings in said plates for actuating said switch springs, the actuator having a retaining portion which varies in thickness along an arc concentric with said pivot, detents engaging opposite sides of the actuator along said are through openings in the plates, and leaf springs for pinching said retaining portion of the actuator between the detents, thereby yieldingly to retain the actuator in one or more of its positions.

10. An electric switch comprising two juxtaposed plates which are offset intermediate their ends to abut each other at their lower ends and provide a space therebetween at their upper ends, the latter ends being bent away from each other to form mounting flanges, said lower ends having registering slots extending upwardly from their bottom edges and opposing grooves extending upwardly from the upper ends of the slots to form a socket which is threaded to receive a screw, a contact block slidably fitted into said slots with grooves on its opposite sides to receive the edges of the slots, a screw extending upwardly through the block and threading into said socket, switch springs mounted on said block with their free ends projecting along said upper ends of the plates, an actuator mounted on a pivot in said space with a handle projecting from the upper open end of the space, operators projecting laterally from the actuator through openings in said plates for actuating said switch springs, a pin bridging said space for limiting the movement of the actuator about its pivot, the actuator having a retaining portion which varies in thickness along an arc concentric with said pivot, rollers engaging opposite sides of the actuator along said are through openings in the plates, and leaf springs for pinching said retaining portion of the actuator between the rollers, thereby yieldingly to retain the actuator in one or more or its positions.

11. An electric switch comprising two juxtaposed plates which are offset intermediate their ends to abut each other at their lower ends and provide a space therebetween at their upper ends, an actuator mounted in said space to swing parallel to the plates about a transverse axis, groups of spring contacts mounted on the outside of said plates with their free ends adjacent said space, switch operators extending from the actuator through openings in the plates for operating said groups, said actuator having a handle extending upwardly beyond said walls and a tail having recesses in its opposite sides, rolling detents engageable with said recesses through openings in said upper ends of the plates to hold the actuator in different positions, and holders for the detents mounted on the outside of said 1ower ends.

12. An electric switch comprising two juxtaposed plates which are offset intermediate their ends to abut each other at their lower ends and provide a space therebetween at their upper ends, an actuator mounted in said space to swing parallel to the plates about a transverse axis. groups of spring contacts mounted 'on the outside of said plates in offset relation to the vertical plane containing said axis, switch operators extending from the actuator through openings in the plates for operating said groups, said actuator having a handle extending upwardly beyond said walls and a depending tail having recesses in its opposite sides, rolling detents engageable with said recesses through openings in the upper ends of said plates to hold the actuator in diirerent positions, and spring-actuated holders for the detents mounted on the outside of said lower ends, said detents and holders being disposed in the region of said plane.

GILBERT SMILEY. CHAUNCEY L. DELANO.

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