US2767271A - Switch - Google Patents

Description

Oct. 16, 1956 e. J-MUCHER 2,767,271

SWITCH Filed Aug. 27, 1954 INVENTOR fiaa giaffiarfler kne, Dela/bio; {/(wn:

ATTORNEYS United States Patent C SWITCH George J. Mucher, Rochester, N. IL, assignor to Clarostat lyfgifi Co., Inc., Dover, N. H., a corporation of New Application August 27, 1954, Serial No. 452,576

1 Claim. (Cl. 200-67) This invention relates to functional and structural improvements in electrical switches and, particularly, to improvements to facilitate the rapid assembly and production of such device and to increase the utility thereof.

In my Patent No. 2,642,506, issued June 16, 1953, which is now the subject of reissue application Serial No. 439,172, filed June 24, 1954, there is disclosed a doublepole, single throw electrical switch of a miniature type having a unique contact arm construction which is specially adapted to carry relatively high current loads. Since its introduction to the commercial field this switch has been widely used and accepted. In order to increase the utility and versatility of this device it is provided herein with an improved contact arm arrangement whereby the basic switch construction of the patent may be adapted to function as a single pole, single throw device and to carry heavier loads than were heretofore possible. In addition it is provided with an improved actuating mechanism whereby the manufacturing cost of this device may be materially decreased.

The principal object of this invention is to provide an electrical switch structure that occupies a minimum space and may be employed under relatively high voltage and amperage conditions.

A further object is that of providing a switch mechanism that may be readily combined with and conveniently operated by assemblies already available on the market. Moreover, this device is readily capable of manufacture by quantity production methods and embodies relatively few parts, each individually simple and rugged in construction; such parts being capable of ready assemblage and when so assembled furnish a sturdy switch mechanism capable of operating over long periods of time with freedom from operating difficulties.

A preferred form of the invention is shown in the appended drawings in which:

Fig. 1 is a plan view of the assembled switch mechanism, with cover removed, showing the contact member in open position;

Fig. 2 is a sectional view taken along the line 2-2 of Fig. 1;

Fig. 3 is an isometric view of a combined limit stud and pivot member of the invention;

Fig. 4 is an isometric view of the toggle switch actuating lever;

Fig. 5 is an isometric view of the contact member of the invention; and

Fig. 6 is a schematic view showing the contact member in its closed position.

Referring to Figs. 1 and 2 the reference numeral 5 generally indicates a casing, the side walls of which are conveniently formed of metal, and the base 6 of which is constructed of dielectric material. The latter has extending from it terminals 7 for connection with electric leads. Conveniently a unit of this type may be disposed to the rear of an assembly which may include a variable resistance or similar device. Therefore, side walls 5 may be provided with suitable openings or tongues (not FF"; 1C6

shown) for the purpose of securing the casing in mounted position. Obviously, any other desired form of mounting structure may be employed. At the center of base 6 a pivot member 8 is secured. This member rotatably supports a disc 9 which is also formed of dielectric material. Extending into the space existing between base 6 and disc 9 are a pair of fixed contacts 10 and 11 which we connected to the base and terminals 7. The disc 9 is formed with one :pair of openings 12 which are conveniently circular and with a second pair of openings 13 which may also be of any convenient configuration. Such openings serving, respectively, a movement limiting devices and anchoring positions for a substantially U-shaped contact member 14 (see also Fig. 5) which comprises two contact arm portions 14a and a connecting portion 14b. Conveniently, member 14 is formed of resilient material having a relatively high coefficient of conductivity, such as phosphor bronze, and is provided with upstanding por-' tions 15 that engage the edges of openings 13 and end portions 16 that engage the edges of openings 12. In addition, member 14 is preformed in a manner such that when assembled as indicated in the drawings, contact arm portions 14a exert spring tension inwardly.

The width of portions 15 may be substantially equal to that of openings 13. The width of portions 16 is less than that of openings 12 whereby the ends of contact arm portions 14:: are free to move outwardly within the limits of openings 12. With the parts under spring tension it follows that with portions 15 in openings 13 and portions 16 in openings 12, member 14 is retained in position relative to disc 9. This is caused by the frictional engagement existing adjacent the ends of each of the aperture 13 and the fact that portions 16 bear against the inner edges of openings 12. Therefore, member 14 is supported by and moves with disc 9 as it rotates about pivot S. It should be noted that the particular formation of contact member 14 enables it to be made of much heavier stock than the corresponding contact member employed in the above-mentioned patent while, at the same time, retaining the same relative resiliency. Thus, the present device can safely carry much heavier current loadings without change in the overall dimensions of the switch mechanism.

In the arrangement shown, disc 9 is provided with a cut-out portion 17 the edges of which serve as one part limiting movements of the disc. A die-cast stud or pivot member 18 serves as the second part and is secured to base 6 in line with cut-out portion 17. It is provided with a reduced portion 23 having bevelled shoulders 21 whereby the edges of cut-out portion 17 are guided into contact with reduced portion 20. By this arrangement the rotational movement of disc 9 is limited to two extreme positions, namely, a clockwise or open position, in which contact arm portions 14a are disengaged from contacts 1i and 11, as shown in Fig. 1, and a counter-clockwise or closed position in which contact anm portions 14a are engaged with contacts 10 and 11, as shown in Fig. 6. It may be noted that the coaction of contact member 14 with contacts 19 and 11 results in a compound wiping action whereby all scars or pittings caused by arcing are smoothed and burnished at each opening and closing of the switch.

In order to provide a snap action device to shift disc 9 to each of its operative posit-ions, a spring toggle mechanism is provided. To this end, stud 18 is provided with a shaft-like extension or pivot member 22 that serves to support an improved three-armed actuating lever rof diecast construction that is generally designated by reference character 23 (see also Fig. 4). Pivot member 22 is provided with a T-shaped end portion 24 that is formed to pass through a double keyhole slot 25 in lever 23 whereby the parts may quickly and expeditiously be assembled and,

when assembled, are maintained in operative relationship of lever 23 coact with the sidewalls of; easing 5 to limit the extent of movement of the lever. The upper arm 28 0f lever 23 is provided with a hole that serves to anchor one end of a V-shaped expansion spring 29 which has its other end anchored in a slottedyoke member Seth-at bears against the outer face of disc 9 and fits into a groove formed in pivot member 8 to prevent axial move ment of the disc relative to the pivot member. as an integral part of lever 23 is the edge of a cut-out portion 23:: which may be engaged by an arm or finger (not shown) whereby the lever may deliberately b'e oscillat ed about pivot 22. h

The provision of the specific arrangement of. actuating lever 23 and pivot member 22 shown herein constitutes a noteworthy advance over the corresponding arrangement shown in the above-mentioned patent and over those heretofore widely used in similar structures of this type. In the prior art devices it was customary to assemble a combination of elements having a function comparable to the present actuating lever 23 ion a conventional stud, and to hold the parts in their proper relationship while the end ofthe stud was peened over to secure the parts in assembled position. This practice was exceedingly costly not only from the standpoint of the labor involved in the assembly operation, but also from the fact that the peening operation frequently caused breakage or misalignment of one or more of the parts, thereby necessitating the scrapping of substantially the entire switch assembly.

F By means of the present arrangement, actuating lever 23 may readily be slipped onto pivot member 22 by aligning double keyhole slot 25 with the T-shaped head 24 of the lever before the disc assembly is inserted in casing 5. The head of the lever is then twisted slightly to engage face 26 with the underside of T-shaped head 24 and the entire assembly is slipped into casing 5, whereby the several parts are locked against axial movement. However, lever 23 is free for oscillating movement about pivot member 22 within the operational confines permitted by the ccaction of lever arms 27 and the sidewalls of casing 5.

of break-age, distortion or misalignment of the several elements is substantially eliminated thereby further reducing manufacturing costs and increasing the reliability and effectiveness of the resulting product. p In operation it is assumed that the casing of the switch is suitably mounted and its terminals connected to electrical leads. Moreover, it is assumed that an operating part extends adjacent the cut-out portion 23a of lever 23, and is capable of being manually or otherwise shifted to actuate the lever. a

If now lever 23 is rocked about .pivot 22 in a clockwise direction as in Figs. 1 and 6, spring 29, which is connected to the lever, functions in the manner disclosed in the above-mentioned patent to provide the toggle action required to shift the parts to one or the other extreme positions. Briefly, the spring is compressed as the parts move because of the diminishing distance occurring beilween the point of connection of the spring and lever Formed in a counter-clockwise direction.

4 7 arm 28 and the point of connection between the spring and retainer 30. When the former connection passes beyond the axis of pivot 8, the spring exerts a force against retainer 36 and disc 9 such that it shifts the latter It is, of course, appreciated that the swing of. the lever occurs during a very brief interval. Therefore, the spring quickly moves through its dead-center position and exerts thrust in the manner aforedescribed.

In any event, with 'such thrust exerted and disc 9 moving in a counter-clockwise direction, spring contact 10 and 11. This has been shown in Fig; 6. Also, as

shown in this view, the arm portions 14a, as they are engaged by the fixed contacts, cam and wipe over the surfaces of the latter. This occurs because of the fact that end portions 16 have less width than the diameter of openings 12. Therefore, these end portions assume final; positions as shown in Fig. 6. Due to'the resilient nature of the contact arm portions, they also function as shock absorbers to cushion the parts against shock as they reach their final positions.

Obviously, a return movement of the .parts from the positions shown in Fig. 6, to those illustrated in Pig. 1 is achieved by simply rocking lever 23 in a counter-clockwise direction. shifted past dead-center position. Therefore, thrust is exerted by the spring against disc 9, resulting in the latter being rapidly shifted in a clockwise direction. these circumstances, contact arm portions 14a no longer bridge contacts 10 and 11 and the circuit is again open.

Thus, among others, the several obfects of the invention, as specifically aforenoted, are achieved. Obviously, numerous changesin construction and rearrangements of the parts might be resorted to without depart-ingfrom the V 'a housing therefor, a pair of spaced contacts mounted by and extending upwardly from said base member, adisc member pivotly supported on said base for oscillation, spaced contacts carried by one of said members, a contact-bridging element carried by the other of said members to electrically close the gap between said contacts, an actuating lever mounted on said base member operatively connected to said disc to move the latter and connect and disconnect said contacts, a pivot stud carried by said base at a point to one side of the point of pivotal support of said disc and a quick-attachable coupling constituted by "a T-shaped end of said stud, a keyhole slot defined in said lever cooperably engaged by said T end and wing portions at edges of said lever which are of :sufiicient length to bear against an internal wall of said housing to limit the pivotal range of said lever and slot whereby the slot is prevented from disengagement with the T end in assembled condition.

References Cited in the file of this patent UNITED STATES PATENTS 1,488,452 Leppert Mar. 25, 1924 1 1,564,016 Perkins Dec. 1, 1925 1,603,523 Douglas Oct. 19,1926 2,235,366 Haselwood Mar. 18, 1941 2,286,162 Sch'ellenger June 9, 1942 2,286,163 Schellenger June 9, 1942 2,304,479 Schellengcr Dec. 8, 1942 2,642,506 Mucher June 16, 1953 Again, spring 29 is compressed and Under

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