US1636678A - Push and pull switch - Google Patents

Description

July 26s 1927. 1,636,6 8

BKA. BENSON I PUSH AND FULL SWITCH FiledMax-chl8.1925

[, yen LLDI' Fatented July 26, 192?.

T E S 1,636,678 PATENT OFFIC.

BEBNHART A. BENSON, OF CHICAGO, IEJLINOIS, ASSIGNOR T0 CHICAGO ELECTRIC MANUFACTURING 00., OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

PUSH AND FULL SWITCH.

Application and March 18, 1925. Serial No. 16,398.

My invention relates to electric switches of the push and pull type, and in its general objects aims to provide an unusually simple and inexpensive switch construction in which certain of the parts are retained in their operative positions by the mere as sembling of the switch without requiring fastening elements for securing these parts to each other. it also aims to provide a switch construction in which the movable contact carrier is mounted with freedom for movement relatively to both the actuating plunger and the stationar contacts, so as to permit it to adjust itsef to any lack of alinement and to deviations in the shape of adjacent parts. 1

More particularly, my invention provides a. switch in which the stationary contacts are disposed at opposite sides of a continuation of the axis of a reciprocable plunger, provides an insulating contact carrier slidably movable between the two stationary contact members and guided at its ends by the walls ot the casing, and provides this carrier and the plunger with formations adapted to be engaged by a simple relative transverse movement of these parts during the assembling of the switch. It also provides a switch construction of this type in which an insulating contact carrier is disposed for engaging the ends of the casing so as to limit the movement of this carrier and of the actuating plunger in both directions, thereby per- Knitting the use of a plunger which can be inserted from the back of the switchand which will have no exposed portion of greater diameter than the threaded supporting nipple through which the plunger extends, and also permitting the casing to hold the contact carrier interlocked with the plunger before the terminal carrying base end of the casing is placed in position.

Furthermore, my invention provides a switch in which the contact carrier can read-- ily be formed of a single and simple punching and in which a material like vulcanized fiber can be employed for this purpose without having a swelling or warping of this material interfere with the operation of the switch. It also provides a switch in which the contact arms normally prevent the contact carrier from disengagement with the plunger, in which these arms yieldingly hold the contact carrier in either the on or off position of the switch, in which casing portions afi'ord positive stops for limiting the movement of the contact carrier in both directions, and in which this limiting does not prevent the contact arms from readjusting showing the operating parts in the 'oti' or circuit-opening position.

Fig. 4 is a bottom view of the switch.

Fig. 5 is an enlarged perspective view of the insulating contact carrier of the switch.

Fig. 6 is a perspective view of the insulating base.

Fig. 7 is an enlarged central and longitudinal section through the forward end of One ot; the contact arms.

Fig.8 is a fragmentary section taken from the line 88 of Fig. 2 to show the position of one end of the contact carrier with respei't to the lateral casing wall.

In the illustrated embodiment, the housing of the switch comprises a rearwardly open metal casing having a cylindrical side wall 1 and a centrally perforated forward end 2, which end has a forwardly extending threaded nipple 3 secured to it, so that the casing can be clamped against a suitable support, such as a dashboard 5 by a nut 6 threaded upon the nipple.

Closing the rear end of the casing is an insulating base 7, here shown as abutting against the rear end of the lateral casing wall 1 and as provided on itsperiphery with a number of recesses 23 each housing a rearwardly projecting finger 22 on the said wall 1, the tips of these lingers 8 being bent over the back of the insulating base 7 so as to secure the base firmly to the main metal member of the casing.

Mounted on the insulating base are a pair of contact members each of which has a foot 9 riveted to the back of the base and carrying a bolt 10 by means of whichthe free end of a circuit wire 11 is secured to this foot. Each of the said terminal members also includes a contact arm 12 which extends through a perforation 23 in the base 7, the two contact arms being disposed at opposite sides of the axis of the cylindrical casing. These contact arms 12 desirably are bowed away from each other and have their 1 free end portions formed into opposed bights convexed towards each other after the manner shown in Fig. 1.

For the movable contact member of the switch I provide a metal part, desirably in ;he form of a hollow rivet 13 extending transversely through a carrier 14 made of insulating material. This carrier is slight- 1y shorter transversely of the axis of the switch casing than the bore of this casing and has its rear portion continuously disposed between the contact arms 12, so that these arms normally maintain its medial plane 15 substantially in the axis of the switch casing.

. I To move the carrier and the contact memof the carrier 14 are provided with interlooking formations, for which purpose I desirably form a groove 28 in the plunger near its rear end and provide the forward end of the carrier with a central and longitudinal slot -spacing a pair of opposed lingers 19 which enter the said groove and which are adapted to engage the opposite walls of' the groove to limit the relative movement of the carrier and the plunger longitudinally of the switch. I also provide the carrier 14 with a recess formation into which the bights of the contact arms 12 can extend towards each other when the carrier is in its rearward position as shown in Fig. 3, for which purpose I desirably enlarge the said slot between the fingers 19 rearwardly of the latter to a width somewhat greater than that of the contact arms 12, after the manner of the perforation 24: of Fig. 5, -so that this perforation normally houses the part of the head 27 back of the lingers 19.

With the parts thus constructed and with the knob 17 of the plunger formed of a diameter not greater than the main portion 16 of this plunger, the fingers 19 of the contact carrier can readily be inserted in the groove on the plunger by a relative transverse movement of these parts before the plunger is slipped through the bore of the nipple 3 from the rear of the switch casing. l/Vhcn thus inserted, the approaching of the 'width of the carrier to the bore of the eaders casing. The base member of the switch, comprising the insulating base 7 with the two stationary contact members already bights to clamp the ,movable contact 13 firmly between them when the plunger has moved the carrier to a certain position. This position is desirably fixed by provid ing each of the bights with a'boss 26 directed toward the other bight and adapted to snap into the adjacent end of the tubular contact member 13, thereby latchingthe carrier as well as the plunger against accidental movement out of the on position of the switch. of such a length that its rear end will abut against the forward faceof the insulating base 7 when the bights of the contact members have partly entered the enlarged slot portion 20 of the contact member, as shown in Fig. 3 so that the engagement of the carrier with the base of the switch will positively limit the rearward movement of the carrier and plunger. At the same time, the

engagement of the bights of the two contact arms with rear wall portions of the slot 20' (which form shoulders engaged by the contact arms) will hold the contact carrier against accidental forward movement. I also desirably make the distance between the movable contact 13 and the forward end of the carrier 14 of a length slightly less than the distance between the said bosses 21 on the bights of the contact arms and a front portion of the casing, so that the carrier can engage this front portion to afford a positive stop for limiting the fo ward move ment of the carrier and plunger, while permitting the clamping action of the contact arms to retract the carrier slightly into a position in which their bosses 26 are socketed in the'ends of the tubular contact member 13.

With the switch thus arranged, it will be seen that both the construction and assembling of the switch are unusually simple. even the cost of the plunger being reduced in comparison with the usual construction since no formations of an enlarged diameter are required to serve as stop formations, so that the plunger can be turned from smaller stock. Since the resiliency of the contact arms will readily permit them to adjust themselves to variations in the length Then I make the carrier 1. 1

of the movable contact member 13, a great exactness in the proportioning of theaparts' is not required. Indeed, thefingers 19 can have a fairly loose fit in the plunger groove entered by them and the carrier does not need to fitthe bore of thei casin-g closely, so that anyv swelling or warpingof this carrier will not interfere with the operation of the switch.

By disposing the lateral ends of the carrier 14 adjacent to the lateral casing wall, I enable this wall to prevent the assembled switch and without requiring. .a close fit between the interengaging parts of the ,carrier and plunger,-so that the carrier canslide or tilt slightly transversely o the plunger inpermitting the contact arms to adjust themselves to firm contacting positions.

one end wall However, while I have illustrated'and described my invention in-a switch supported from its front and one having desirableshapes of various parts, I donot wish to be limited to the details of construction and.

arrangement thus disclosed. Obviously,

many changes might be made-without departing either from the spirit of my invention or from the: appended claims,

I claim as my invention 2- 1. An electric switch including a casilig having opposed end walls, a pair of spring contact \arms in the casing, an insulating member having a slot ad'acent one end thereof, a contact element-between the slot and the opposite end of the member, and operatin -means for said member engageable in said slot, said arms being formed with parts which in one osition of the member engage the wall efining the inner end of the slot thereby to' hold'thesaid opposite end of the member engaged. with the inner face of of the casing, said operating means extending through the other end wall of the casing.

2. An electric switch including a casing having opposed end walls, a pair of spring contact arms in the casing, an insulating member loosely disposed within the casing and having a slot adjacent one end thereof, a contact element between theslot and the opposite end of the member, and operatin means for saidmember engageable insai "member, and operating means 1 thereby to hold slot, said arms being formed with parts which in 'oneposition of the member engage the wall defining the inner end of theslot thereby to hold the-said oppositeendof the member engaged with the inner face of one end wall of the casing, said operating means extending through the ot .er endwall of the casing. 1 3. An electric switch including acasing having an. end wall, a pair of spring contact arms in the casing, ber, loosely disposed within the casing and havinga slot extending ate point lengthwise of the member and an insulating memfrom 'an intermedlthrough an end thereof, a contact element between the slotand the opposite end of the for said'member having a part thereof extending into the slot, said arms being formed with parts which in one position of the member engage the wall defining the inner end of the slot the said opposite end of the member engaged with the end wall of the casing.

4. An. electric switch including a casing having an end wall, a pair of spring contact arms in the casing, an insulating member f loosely-supported within the casing and hav mg a substantially V-shaped slot extending from an intermediate point lengthwise of thefmember and through an end thereof, a contact element between the slot and the opposite end of the member, and operating means for said member having a part loosely extending into the slot, said arms being formed with parts which in one position ofthev'member engage with each ofthe walls defining the inner end of the V-shaped slot thereby to hold the said opposite end of "the'member" engaged with the end wall of the 'casing.

5. An electric switch including a'casing, a

pair of spring contact'arms in the casing, an

insulating member movable in said casing and having a contact, said. member being loosely supported at one end by the. arms,- operating means forthe member, and means to loosely connect the opposite end of the member to the operating means whereby to. allow the member to move vertically and to. rock so as to permit the contacts of the arms to make electricalcontact with the contact of the member. v

6. In an electric sw1t ch,-a casing having anend, contact arms therein, an insulating member in the casing having a pair of walls which diverge relative to said end of the casing and operating means for the mem ber, said arms engaging the respective di vergent walls so as to force and hold the member againstsaid end of the casing.

Signed at Chicago,

BERNHART A. BENSON.

Illinois, March 6th,

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