US2627567A - Switch - Google Patents

Description

R. B. BELL SWITCH Filed Sept. 27, 1947 Feb. 3, 1953 `Patented Feb. 3, 1953 SWITCH Rupert B. Bell, Ann Arbor, Mich., assignor to King-Seeley Corporation, Ann Arbor, Mich., a

corporation of Michigan Application September 27, 1947, Serial No. 776,497

6 Claims. (Cl. 2011-153) 1 The present invention relates to an electrical switch of the type particularly adapted for operation by a mechanical means, such as the moving part of a machine, a system of levers or a 2 housing section includes a contact receiving recess 'I formed'in the face 8 which mates with the corresponding face of the other section. The recess 'I is connected by means of a pair of slots 9 and mechanical timing device. 5 IU to the rear face I I of the section. The recess It is the'general object of the present invention 'I is also connected by a semicircular slot I2 to the to provide a switch of the type mentioned charfront face I3 of the section, and the bottom of acterzed by its extreme simplicity, low cost and the recess is formed with three aligned spaced ease of assembly grooves or recesses I4, I5 and I 6, which, as here- Other objects and advantages of the invention w inafter pointed out, serve to locate and support will become apparent from the following specithe contact elements Within the housing sections cation, the accompanying drawing and the apon assembly. The housing sections may be pended claims. secured together in any suitable manner, such as In the drawing: by a pair of bolts, which bolts are adapted to pass Figure 1 is a rear elevation of the switch, show- 15 through openings Il and I8 formed therein. It ing the same mounted on a supporting panel; will be noted that the openings Il are co'unter Figure 2 is a sectional view taken on the line sunkto receive a raised annular boss I9 formed 2-2 of Figure 1; on the face 8 of each section around the opening Figure 3 is a sectional view taken on the line I3 therein. As a result of this construction, the 3-3 of Figure 1; i i o engagement of thebosses I9 within the counter- Figure 4 is an exploded view, showing in persunk portions of the openings I'I prevents relative spective all of the parts forming the switch; and displacement between the housing sections I and Figure 5 is a fragmentary section taken on the 2 in a plane Parallel t0 the mating faces 8 and ,line 5-5 of Figure 3. i eliminates the necessity of having a close nt be- The principles of the invention are shown in 5 tWeen the Openings l'l and I8 and the bolts 20 the drawing as incorporated in a normally open which secure the housing sections together and single pole switch of the type employing two pairs 't0 any Suitable Supporting member, Such as the of mating contacts which are connected in paralplate 2|. A lel and which successively engage when the switch The StatiOnaIy contact element 3 comprises a is closed and successively disengage in the reverse 30 single at plate 22 llaVing a pail 0f ccntact eleorder when the switch is opened, thus insuring ments 23 and 24 xedly secured thereto. The that any arcing at the contacts will always occur l-Dlate 22 is formed Of any electrically conductive at one pair of engaging contacts and` leaving the material, Such es copper 01' brass, and is provided other pair of contacts free of any impairment with two pairs of Oppositeiy extending ears 25 which would otherwise adversely affect their cur- 25 and 26. The Contact elements 23 and 24 are rent carrying capacity. It will be appreciated, secured to the plate by riveting, and the contact however, that the principles of the invention are 23, Which is, in itself, in the form 0f a rivet. applicable to other forms of switch mechanisms. Serves t0 secure a terminal 2l t0 the plate, in the such as normally closed switches or switches manner best ShOWn in Figure 2. which incorporate only one pair of engageable 40 The mOVable ccntact element 4 comprises a contacts. suporting plate 28, which is generally rectangu- T As shown in the drawing, the complete switch lar in form and of the same dimensions as the assembly comprises a pair of mating housing sec- DOItiOn 0f plate 22 Which includes the ears 26 tions, indicated generally at I and 2, within which and contact 24. VA spring bronze or other suitable are supported a stationary contact element 3 and 45 electrically conductive flexible contact arm 29 a movable contact element Il. The movable conand a terminal 30 are fixed to the plate 28 by tact is actuated by means of a button 5, which means of a double ended rivet 3|, the arm 29 and projects through a suitable opening in the housthe plate 28 being held in spaced relation by a ing and is actuated by one end of a reversely bent head 32 located intermediate the ends of the rivet. leaf spring 6, en The arm 29 has riveted thereto a pair of contact An important feature of the invention resides elements 33 and 34, the formel' being located inin the fact that the housing sections I and 2 are termediate the ends of the arm and the latter identical to each other, with the result that both adjacent the outer extremity thereof, maybe formed on the same set of dies from any A further important feature of the invention `suitable material, such asamolded plastic. Each 5.5-resides in the fact that the symmetrically arranged recesses I4 and I5 in the identical housing sections I and 2 may, due to the construction and arrangement of the contact elements 3 and serve to locate and support either one ci the contact elements interchangeably. Thus, if the parts are assembled while they are in the relative positions indicated in the exploded View of Figure 4, the ends oi plate 2S are ntted within the notch I4 in section I and the notch I@ in section 2, while the ears 26 on the contact element 3 are tted in the notch I6 of section I and the notch I4 of section 2, in the manner best shown in Figures 2 and 3. However, if desired, the position of the contact elements 3 and il may be reversed without in any lway changing the construction or mode of operation of the final assembly. In that case, the ends of the plate 28 are tted within the recess IS in housing section I and I4 in housing section 2, `while the ears 26 are iitted within the recess Il?. of section I and IS of section 2. In either case, the ears 25 of section 3 nt within the recesses I of both housing sections and in both cases the terminals 27 and 3d will lie in the openings formed by the mating slots 9 and Iii. The fact that the contact elements may be interchangeably positioned within the housing greatly facilitates assembly, since the parts cannot be assembled in an improper relationship and it is unnecessary to manipulate the housing sections to one of the two possible positions in order to achieve a successful assembly.

When the switch is assembled, the button E, which is an entirely loose piece, is inserted in position with its projecting end extending through the opening formed by the mating notches I2. The external operating spring l'6 has a U-shaped end portion 35, which is adapted to 'fit within an L-shaped recess 33 which is formed in the face 8 of each housing section and which opens to the front face I3 of each section. The width of the spring 3 is almost twice the depth of the recess 36 formed in each section, with the result that on assembly the spring lies on opposite sides of the plane containing the mating faces Ii of the housing sections. The U-shaped end of the spring loosely its within the L-shaped recess 36 and forms, in effect, a pivotal mounting for the end of the spring. The connection thus aiforded between the spring and the housing cannot be disconnected without separating the housing sections. The opposite end of the spring is provided with a U-shaped section having a terminal portion 3l which engages the operating button 5.

It will be understood that the spring 6 may be omitted if desired, and the switch operated by direct actuation of the button 5. However, since in mechanically operated switches of the type here involved it is frequently diiiicult to eliminate overtravel of the mechanical device which operates the switch, it is desirable to'prcvide, in connection with the switch mechanism, means to permit such overtravel without damage to the switch, itself. For that purpose, the spring 6 is provided. Thus, on application of a switch actuating force to the spring in the direction indicated by the arrow in Figure 2, the switch contacts will engage and thereafter the spring may further distort to permit overtravel, if any, in the operating mechanism which exerts the force. It will be observed that since the switch closing force is applied by button 5 to the central portion of the iiexible arm 29, the contact element 34 will engage its mating contact element 24 before engagement between the contacts 33 and 23 occurs. Conversely, as the switch is opened, contacts 33 and 23 will disengage before disengagement of contacts 34 and 24 occurs. Consequently, all of the arcing will occur at the contacts 24 and 34. This will leave the surfaces of the contacts 23 and 33 unpitted and thus prevent impairment 0f their current carrying capacity. The contacts 24 and 34 are provided solely for the purpose of taking the arcing on closure and opening of the switch in the manner described above, and are otherwise unnecessary since all of the current may be carried by the contacts 23 and 33.

It will be noted that since the two housing sections I and 2 are identical, there are two sets of recesses 36 in each housing. This permits mounting of the spring 6 at either end of the housing without changing the mode of operation or characteristics of the device. The external mounting of the leaf spring 6 is particularly advantageous in that it permits direct observation and adjustment of the amount of -overtravel provided thereby. As a result, damage to the switch mechanism due to excessive overtravel in the operating mechanism is easily'avoided.

A further feature of the invention resides in the detailed construction of the notches or recesses I4 and I6. Asbest shown in Figure 5, the notch It is ofgreater width than the ears .26 on plate 22. However, one side of the notch is formed with a centrally located projection '31 while'the opposite side is provided at each end with a pair of projections 38. The arrangement is such that whenthe-ears 23 are forced intothe notch or recess, the projections 31 and 38 bend the ears in the manner best shown in Figure 5. For this purpose the outer ends of the projections are slightly rounded or inclined in order to lbend the ears by a camming action as theyare forced into the recess.

It will be understoodk that the notch or recess I4 is constructed in the same manner as'notch Iii and similarly coacts with the ends of plate 28.- Also plates 28 and'22 are of the same thickness with the result that plate .28 maybe fitted in either notch and the ears on plate 22 in the other.

Two important-advantages flow from the'above .described notch or recess construction. In the iirst place, the projections 3l and .38 positively grip the ears28 and the ends of plate 28 and thus Yhold the associated contacts in a fixed position within the housing independent of variations in thethickness of the plates 22 and 28 and the width of the notch which result from normal manufacturing tolerances. Secondly, the friction induced by the ltendency of the bent ears and bent endsv of plate 23 to return to a nat condition holds the two housing sections together suiiiciently to permit normal handling of the assembled switch prior to insertion of the permanent fastening means (rivets or bolts) through lopenings I'I and I8.

While, as shown in the drawings and described above, the notches I4, I5 and I6 are recessed'below the bottom surface of the recess I, it will be apparent that this is not necessary since the surfaces which engage the plates 22 and 28 and hold them in position may be formed on .projections extending above the general level of the bottom of recess 'I without changing the principle or-advantages of the invention.

While only one form of the invention is shown and described herein, it will be apparent that variations in the details of construction may be indulged in without departing from the spirit of the invention or the scope of the appended claims.

What is claimed is:

1. A. switch, comprising a housing formed of two identical sections having mating recesses forming an internal chamber for the reception of relatively movable switch contacts, said sections h-aving mating slots through the side walls of said recesses adapted to receive switch terminals, a pair of switch contact elements each having a supporting portion and a pair cf equally spaced contact portions and a terminal, the contact portions on one of said velements being xed to a exible strip one end of which is fixed to the supporting portion of said element, the supporting and contact portions being located within said chamber and the terminal portions lying in said mating slots, the contact portions on the iiexible strip being so positioned that on fiexure oi said strip in one direction the contacts on one element engage the contacts on the other in succession and on ilexure in the opposite direction said contacts disengage in the reverse order, each of said housing sections having surfaces formed to engage the supporting portion of each of said contact elements and support the elements in proper relative position, each housing section being symmetrical with respect to a central plane extending transversely thereof so that said contact elements may be reversed without altering the relative positions of the contact portions or said elements, and means projecting from ie housing for flexing said strip.

2. A switch, comprising a housing formed of two identical sections having mating recesses forming an internal chamber for the reception of relatively movable switch contacts, said sections having mating slots through the side walls or" said recesses adapted to receive switch terminals, a pair of switch contact elements each having a supporting portion and a contact portion and a terminal, the contact portion on one of said contact elements being fixed to a exible strip, one end of which is fixed to the supporting portion of said one of said elements, the supporting and contact portions being located within said chamber and the terminal portions lying in said mating slots, the contact portion on the flexible Strip being so positioned that on flexure of said strip in one direction the contact on one element engages the contact on the other, each of said housing sections having surfaces formed to engage the supporting portion of each of said contact element-s and support the elements in proper relative position, each housing section being symmetrical with respect to a central plane extending transversely thereof so that said contact elements may be reversed without altering the relative positions of the contact portions of said elements, and means projecting from the housing for flexing said strip in said one direction.

3. A switch, comprising a housing formed of two identical sections having mating recesses forming an internal chamber for the reception of relatively movable switch contacts, said sections having mating slots through the sidewalls of said recesses adapted to receive switch terminals, a pair of unitary switch contact elements formed of electricity conducting material and each hav ing a supporting portion and a contact portion and a terminal, the supporting and contact portions being located within said chamber and the terminal portions lying in said mating slots, each of said housing sections having surfaces formed to engage the supporting portion of each of said contact elements to hold said supporting portions in xed relation to said housing and support the elements in proper relative position, one of said elements being deformable to move the contact portion thereof into engagement with the contact portion of the other of said elements and means projecting from the housing :for so deforming said one of said elements.

4. A switch as dened in claim 3 wherein the cont-act portion and terminal of each contact element is permanently fixed to the supporting portion thereof.

5. A switch comprising a housing formed of a pair of mating sections having recesses which combine to form an internal chamber, and switch mechanism disposed within said chamber mounted on said housing and including a pair of sheet metal mounting plates within said chamber and extending in planes transverse to the plane of juncture of said sections, and a pair of relatively movable switch contacts carried respectively on said plates, each of said sections having surfaces formed in said recesses which distort said plates from their free condition and frictionally engage said mounting plates at opposite sides thereof to hold said plates in a distorted condition.

6. A switch as defined in claim 5, wherein said mounting plates have laterally extending portions received in said recesses and engaged and distorted by said surfaces.

RUPERT B. HELL.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,830,084 Bjorndal 1 Nov. 3, 1931 1,981,064 Norviel Nov. 2&0, 1934 1,987,025 Peterson Jan. i8, 1935 2,053,373 Money Sept. 8, 1936 2,304,764 McAllister Dec. 8, 1942 2,332,911 Hausler Oct. 26, 1943 2,341,931 Lloyd Feb. 1.5, 1944 2,385,165 Sears Sept. 18, 1945 2,398,996 Benander Apr. 23, 1946 2,419,072 Hall Apr. 1.5, 1947 2,456,548 Weiner et al Dec. 14, 1948 2,459,427 Humpage Jan. 18, 1949 2,497,484 Wood Feb. 14, 1950 2,507,381 Morse May 19, 1950 OTHER REFERENCES Ser. No. 322,436, Leifer (A. P. CL), published May 18. 1943.

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