US1294053A - Electric switch. - Google Patents

Description

'F. W. COLE.

ELECTRIC SWITCH:

APPLICATION FILED JAN. 3. 1915 Patented Feb. U, 1919.

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FREDERICK W. COLE, 0F NEWTON HIGHLANDS, MASSACHUSETTS, ASSIGNOR TO GAME WELL FIRE ALARM TELEGRAPH COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

ELECTRIC SWITCH.

Specification of Letters Patent.

Patented Feb. 11, 1919.

Application filed January 3, 1916. Serial No. 69,783.

To all whom it may concern:

Be it known that I, FREDERICK W. COLE, a citizen of the United States, residin at Newton Highlands,inthe county of Mi dlesex and State of Massachusetts, have invented an Improvementin Electric Switches, of which the following is a specification.

The invention is directed to an electric switch which, while capable of general use, is particularly well adapted for use as a shunt switch for fire-alarm signal boxes.

. In switches of the spring type, with which elements being shown in closed relation.

Fig. 2is a similar view with the switch members in 0 en relation.

Fig. 3 is a ragmentary detail, illustrat ng the engagement of the switch elements.

Fig. 4 is a side elevation of amodified form-of switch embodying this invention.

Fig. 5 is an enlarged fragmentary detail,

I tivemovements of the switch elements.

In the form illustrated in Figs. 1 to 3, 10 represents the base to which the switch-members are, or may be, secured. One such member, hereinafter referred to as the stationary member, is here shown as comprising a resilient supporting strip of metal bent to form an attaching-portion 12, a, lateral body-portion 13, approximately at right angles to the attaching-portion 12, and a switch terminal or engaging portion 14, the

latter being bent at an acute angle to the plane of the, body-portion 13. The other switch member, hereinafter termed the movable switch member, is shown as consisting of a resilient supporting strip of metal bent to form an attaching-portion 16, adapted to be secured to a base, a body-portion 17, and a terminal or engaging-portion 18, the latter being disposed at an obtuse angle to the body-portion 17. The movable switchmember is formed intermediate the bodyportion and attaching-portion in a full curve 21, so that the body-portion and attaching-portion are approximately parallel,

under normal conditions, and at appreciably spaced relation. This return bend 21 constitutes the main point for permitting necessary movement of the switchelement 18. A

return bend 20 between the body-portion l3 and switch-terminal 14 of the stationary switch member, and of approximately an acute angle, though slightly rounded, constitutes the main point of movement of the switch terminal of' the stationary member. The respective switch-members are secured on the base so that in the normal position of being thus oppositely disposed. Furthermore, it is to be particularly noted that the switch-members are relatively disposed so that the outer sides of the angles of their angularly formed ends enga e each other, as contrasted with the inner sides.

Movement is imparted to the movable switch-member by a plunger, hereshown as comprising a head or end-portion 30, and a stem 31, the latter extending through alined holes in the body-portion 17,- and attachingportions 16 of the movabl member, and

through a hole in the base. The plunger is adapted to be moved in a straight line, that is, at right angles to the plane of the bodyportion 17 of the movable member, the movement being imparted to the plunger, in the signal-box use ofthe switch through the closing of the signal-box door. It will be further noted from Fig. 1 of the drawings, that the opening for the plunger in the body-portion 17 of the movable switch-element is of increased diameter as compared with the stem of the plunger, permitting a v as the terminal 18 is moving in approximately a line parallel to the line of switch' the greater pressure applied to the plunger, the 0 may be termed a pivotal support. The relative'disposition of the terminals 14: and 18 is such that in the continued movement of the plunger, these terminals engage, and engage throughout their maximum area upon the initial contact. The further movement of the plunger causesthe tepninal 18 vto slide to a slight degree upon the'terminal 14, resulting in a wiping action to increase the certainty of maximum conductivity. During such wiping action it will be obvious that the relativ positions ofthe terminals change, and thatthis comparatively slight change in relative positions is compensated for through the fact. that the free' endiof, theterminal 14 is opposite the connected end of the terminal 18, and vice versa,-so that the efiectis to still maintain the full maximum area of contact. Durin this sliding movement it will be noted that closing pressure, and is meeting a terminal disposed at an angle to such line of pressure, that is, the terminal 14, hence there is of necessity an increased pressure incident to and during such advance ofthe terminal 18, said terminal 18 acting as a wedge or in a wedge-like stated, the terminal 18, by reasonof its comparatively remote yielding point, namely, the bend 21, is somewhat more flexible than the terminal 14, owing to its comparatively close yielding point, namely, the bend 20. It, therefore, follows that the terminal 18 yields to a'somewhat greater extent than the terminal 14, and that as the yielding point of such terminal 18 is in the form of a return bend, and comparatively remote, such yielding will be in the nature of a spring resistance, which spring resistance increases as the necessity for such yielding increases,'so that the further the movement of the element 18 toward greater the strength of closing position, the the spring bend 21 to resist relatively upward movement of said element, and hence of contact between the switch terminals.

One of the circuit wires may be connected with a screw 35, which is, or may be applied, y as one of the attaching screws for the movable member, and the other circuit wire con- .nected to a binding post 40, the threaded end of which extends through the base and serves as an attaching screw for the statlonary member. To facilitate the connecmanner against the terminal 14L. As before tion of the circuit wires to the binding-post, the upper'end-portion of the latter may be beveled and the binding screw extended Eherethrough in diagonal relation with the In the embodiment of the invention shown in Fig. 4, each switch-member comprises a body portion 50, which also serves as an attaching portion, and-an engaging-portion or terminal 51, the engaging-portions being arranged obliquely to the body-portions, in

this instance being arranged with relation thereto. tions or terminals are disposed in parallel relation and relatively oppositely disposed, and the angularly formed switch-members are arranged for engagement at the outer sides oftheir angles, and hence have substantially the same co-action to that de scribed in connection with the form shown in --Fig. 1. In this instance, however, the wedging action is secured through the comparatively equal yielding of both members, each forming a yielding abutment to resist movement of the other.

'I claim: I I

1. In an electric switch, astationary switch member and a movable switch member, each switch member formed of a resilient strip having an attaching portion for attachment to a base, a resilient body portion extending from the attaching portion, and a reflexed fiat contact portion at the end of said body portion, each stationary switch member being resilient as a whole from the attaching portion strip and each-contact portion thereof being independently resilient from its junction with the body portion to its end, said switch members bemg oppositely arranged 'lwith their contact portions at other than a right angle to the line of switch closing motion whereby the contact portions engage with a wedg'ing action and, in the open condition of the switch, are spaced apartsubstantially parallel to each other, the above described construction of the switch members being such that, in the closing movement of the switch, said contact portions are moved into substantially simultaneous contact over their entire contacting faces and, with a continued switch closing movement, said contact portions maintain their substantially full contacting area with a sliding engagement therebetween, the independent resiliency of the contact portions maintaining contact therebetween over substantially the entire contact area and the resiliency of each member as a whole permitting the sliding of the contact surfaces while in full area of contact.

2. In anelectric switch, a base, a stationary switch member, comprising a resilient strip having a reflexed' portion attached to said base, an upright portion extended above at obtuse'angles The engaging-porto the extremity of the said base,and a reflexed portion downwardly extended toward said base at the end of said upright portion to form the contact portion of said switch member, a movable switch member formed of a resilient strip having an attaching portion secured to said base, and refiexed to provide a resilient arm extended toward the contact portion of the stationary switch member and having an upwardly extended end forming the contact portion f said movable switch member, which contact. portion is arranged to be substantially parallel with the contact portion ofthe stationary switch member in the open circuit condition of'the switch, said movable switch by its resiliency tending to normally remain in open circuit position, an operating member therefor including a rod slidably arranged in said base and extended through said resilient arm and in normal engagement therewith said rod having an abutment,adapted to engage with said base to restrict the open circuit movement of said movable switch member, a movement of said operating member toward said base serving to move-the contact portion of said movable switch member into substantially sin'mltaneous parallel engagement with the contact portion of said stationary switch member and, upon continued movement of said movable switch member, to continue to maintain said substantially parallel engagement with the contact portion of said stationary switch member, and said movable switch member through its resiliency serving to return itself and said operating member to normal open circuit position upon release from closed circuit position. 7

3. In an electric switch, two resilient strips, each bent to form an attaching portion, a body portion, and a terminal, said terminals being arranged at an angle other than aright angle to the line of switch closing motion thereby to co-engage with a wedgingaction, and being deflectable wherebythey inay engage throughout their full contact area upon initial contact. and continue such area for contact as the closing motion continues, and a sliding plunger extended through the wall in one of said bodyportions and adapted to be moved longitudinally to move said body-portion to cause its terminal to engage the other terminal.

In testimony whereof, I have signed my 7 name to this specification in the presence of two subscribing witneseses.

FREDERICK W. COLE.

l/Vitnesses B. J. NOYES, v V H. B. DAVIS.

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