US2614186A - Snap switch - Google Patents

Description

0st, 14, 1952 o. B. SUTTON Erm.

SNAP SWITCH Filed Sept. 16, 1948 Patented Oct. 14, 1952 SNAPl SWITCH Otis B. Sutton, Canton, and Herbert W. Wilson, North Canton, Ohio, assignors to The Hoover Company, North Canton, Ohio, a corporation of Uhio 'Application September 16, 1948, Serial No. 49,562

4 Claims. (Cl. 20D-467) This invention relates to an improved snap switch and more particularly to a simplified snap acting toggle mechanism having fewer components of simplified design.

Accordingly, it is an object of the` present in' vention to provide a snap switch having a simplified toggle mechanism of fewer components, sturdier in construction, more positive in operation and of longer life than those heretofore known. Still other objects and advantages will become apparent from the following description taken in connection with the accompanying drawings in which:

Figure l is a vertical sectional view through an illustrative embodiment of the invention;-

Figure 2 is a cross sectional view of the assembled switch on line 2 2 of Figure l; and

Figure 3 is a perspective view oi a bearing plate employed in the` toggle assembly.

Casing halves i@ and ll are preferably formed from molded thermoplastic material and meet along a vertical median plane to form a switch housing. An irregularly shaped cavity i2 formed partially in each casing half houses the toggle mechanism, a part of the operating handle, and the inner portion of the terminal members. An opening i3 extends from this cavity through the top of the casing halves and forms an operating passageway for the switch handle lf3.

The toggle mechanism unit will now be described. Two side links of stamped insulation material lli-i6 have their upper ends journaled on pin l5 which, as shown, also pivotally supports operating handle Ill. Each link is provided with a keyholeslot il at the opposite end to receive and support a contact bridging spindle i8 having rounded ends to facilitate wiping action with the contacts. lThis spindle is conveniently turned from brass stock and is provided with end grooves to receive the sideflinks and a substantially centrally disposed groove i9. Journaled in groove i9 is a T-shaped toggle strut 2i] which is stamped from sheet material. The top side oi the T is notched at 2l to form a bearing with the bottom of groove i9 oi the spindle.

Projecting from the lower, pivoted end of handle M is a round ended toggle pivot arm 22. This arm is shown integral with the handle and it is oiset from the vertical center line of the handle in each oi two planes at right angles to one another. The nature and extent of the offset in each direction can be best understood by observation of Figures 1 and 2. It will also be noted from Figure 2 that strut 20 is offset intermediate its end so that its top inner 'face lits against one face of pivot arm 22. The strut is held in the position just described by a bearing platev 23 in cooperation with compression spring 24 the lower end of which rests against the inside T head of the strut. The opposite end of the spring bears against the *lowerufsideio'l plate 23 and holds it firmly Vagainst the rounded end of pivot'arm 22.

As best shown in'Figure v3,"washer' 2'3is dishd at its mid portion 25 and is provided withfa guide slot 2t to receive the upper end of strut 20; From the foregoing it will 'be cleanthat'the peculiar construction of the washer of the bearing plate 23 togetherwith the slot 25' constitutes a very simple and yet positive means lost motion connection for locking the toggle"as'sernblytoi` gether while permitting limited co-planarvmovee ment between the strut and theface of the pivot arm. The spring presses against the T head of the strut to maintain the strut 'iirmly seated in' groove I9 of the spindle while its upper endfmaintains the bearing plate firmly againstjtheround= ed edge oi pivot arm 22. rhus, the spring Valways acts to urge the spindle and the pivot armiapart; The flat sides of the bearing plate cooperate with the upper end of the strut, the endoffthepivot arm and theinner faces of links i6 to 'maintain all of the parts in their proper relativepo's'ition at all times. v

The terminal anchor construction willzno'w'be described and will beundrstood to besubstantially identical with that disclosed 'in theapplica-.f tion of Herbert W. Wilson (Hoover Case G-19) being led concurrently herewith. "It comprises kthree separate elements in addition `tothe two casing halves. These are the two metal V,terminal strips 2l, 28 and separatorstrip'ZB vorinsulationmaterial. `These elements fit about bosses 32 formed integrally with each of the cas-,- ing'halves anddescribed in detailr in the 'abovementioned application. The inner `ends of -.the

of bridging contact withthe terminal: strips.

The casing halves may be heldin assembled position by a pair .of rivets 30, 3l the latterf'of which passes through terminals'2l, 28 and sepf arator 29, it being understood that the insulated bosses surround vrivet, 3l vand separate it from each vof the terminals as well as from the 'sep-M arator strip. l f 1f-- In assembling the toggle mechanism, pinjllis passed through the opening'in handle I4 and side links i6, I6 are tted over the` opposite endsuof the pin. Next, spindle i8 is assembled through keyholeopenings l1, Il in the lower endv of' the side links. Next, spring 24 is insertedover strut 28 and bearing plate 23 is inserted over the upper .end of the strut. This assembly istheninserted 3 betweenthc side links with notch 2| .of the T riding ingroove 'I9 of the spindle and the spring is compressed suii'ciently to permit bearing plate 23 to be inserted beneath the rounded end ef pivot arm 22.

The toggle unit is a stable assembly at this stage and may be readily handled without danger of the parts separating from one another. Next, place terminal strip 28 in Vposition over boss l32 in casing half I0, and insert the toggle unit in its proper position in cavity I2. Separator 29, top terminal 21 and casing half Il are added in the order mentioned. Thereafter the assembly is securely locked together by the placement of rivets. 30 and 3l; n I

As will be understood from the foregoing, the entire switch is readily assembled without the use of any tools whatsoever it being merely necessary toslip the parts together and place them vbetween the casing halves. Furthermore it is noteworthy that no special jigs or other xtures are required inthe assembly operation. v

The described construction permits of the use of a heavy compression spring which is maintained against buckling by the single strut 20 stamped from heavier material than is feasible to use. with prior constructions making use of U- shaped toggle struts or their equivalent. It will further be clearvthat the use of a single strut permits the use of stronger and heavier parts in all components of the toggle unit without increasing the over-all dimensions thereof. This adds greatly to the reliability, sturdiness, and posltiveness of action of the switch. It will be equally clear that the life of the parts will be materially increased and that there Will be far less likelihood of damage thereto in the assembly operation.

, While only a single embodiment of the invention has been disclosed, it is to be understood that numerous lvariations in the design and disposition of the parts is contemplated Awithout departing fromv the spint of the present invention.

It is to be understood' that the protection herein applied for is not coniined to the particular features or elements set outin the following claims. Protection is herein applied for for any one or more of the features or elements referred to in the following claims or described in the foregoing specification or shown in the accompanying drawings either independently or in combination.

Y. 1. A toggle mechanism for a snap -action switch comprising a generally U-shaped contact bridgingr means, means `for pivotally supporting the upper ends.y of said U-shaped means for limited oscillatory movement between closed-switch and openswitch positions, an operating handle for said toggle mechanism, means providing a common pivotal axis for said handle and for the upper ends of said U-shaped means, said handle including a pivot arm positioned between the legs of said U-shaped means, a toggle strut comprising a single substantially flat, one piece, T-shaped member having a single leg and a single head of uniform thickness a centrally disposed notch in the top edge of said T-head, a single centrally disposed annular groove in the bight portion of said U-shaped means having a width slightly greater than the thickness of said toggle strut for receiving and pivotally supporting the notched .T head of said strut, the other end of said strut vbeing disposed against one face of the pivot arm on said operating handle, a bearing plate having a dished central portion adapted to bear against the end of said pivot arm and a single slot adjacent thereto adapted to receive the end of said strut for free to and fro movement therethrough, and a compression spring supported between said bearing plate and the T head on said strut, said spring acting to hold the aforementioned elements of vsaid toggle mechanism in assembled position aswell as means for resiliently holding said U-shaped contact bridging means in either said closed-switch or said open-switch position.

2. A snap action switch comprising a two part housing of insulating material, a switch operating handle opening in said casing, a pivot pin extending crosswise of said opening and supported by said casing, an operating handle mounted on said pivot pin and having a pivot arm extending into said casing, a pair of links having one end pivoted to said pin at either side of said pivot arm, a contact bridging member carried in the opposite ends of said links, a single one piece, T-shaped toggle strut having a single leg and a single head stamped from sheet material, a centrally disposed bearing notch on the top .of the T head of said strut, a single centrally disposed groove in. said contact bridging member having a width slightly greater than the thickness of said strut in which said notched T head is pivotally seated, the end of said strut opposite said T head being disposed adjacent one face of said pivot arm, a bearing plate having a central depression to receive the end of said pivot arm and a slot through which the end of said strut slides freely, a compression spring closely embracing said strut and disposed between said T head and said bearing plate so as to urge said pivot arm away from said contact bridging member, and a pair of switch contact members supported in said casing and disposed to be bridged by said contact bridging member when said snap acting mechanism is in one oi its two stable positions.

3. A toggle mechanism as defined in claim l in which the center line of said pivot arm is 01T set laterally from a median plane between and parallel to the legs of said U-shaped contact bridging member, said toggle strut being disposed on t'iat side of said pivot arm closer to said median plane whereby said strut and said compression spring function smoothly and without transmitting a twisting movement to said U- shaped member.

4. A toggle mechanism as defined in claim 1 in which the end of said pivot arm in contact with said bearing plate is off set laterally from a plane which includes the entire pivotal axis of said operating handle and the longitudinal center line of said handle whereby said spring is more eiective in holding said contact bridging means in closed-switch position than in said open-switch position.

O'IIS B. SUTTON. HERBERT W. WILSON.

REFERENCES CITED The following references arefof record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,474,013 Benjamin Nov. 13, 1923 1,969,263 Gaynor Aug. '7, .1934

`1,998,962 Krieger Apr. 23, 1935 2,186,154 StOekIe Jan. 9, 1940 FOREIGN PATENTS Number Country Date 549,724 Great Britain Dec. 3, 1942

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