US1956026A - Switch contact - Google Patents

Description

April 24, 1934. w, HElNRIcH 1,956,026

SWITCH CONTACT Filed May 6, 1929 2 Sheets-Sheet l Q $2; Ellyn! INVENTOR WALTER a. HE/NQ/CH 24441, ILL

W. A. HEINRICH SWITCH CONTACT April 24, 1934.

VIII

Filed May 6, 19 29 INVENTOR WAL TEA A. Hf/N/P/CH I BY M I ATTORNEYS Patented Apr. 24, 1934 .UNlTEDSTATES PATENT OFFICE 1,956,026 swrron CONTACT .Walter A. Heinrich, St. Louis, Mo.

Application May 6, 1929, Serial No. 360,781

3 Claims.

This invention relates to disconnecting switches for high tension electric lines, and more particularly an improved self-aligning contact structure for disconnecting switches.

5 The switch of my invention contemplates the use of paired terminals carried by a suitable base from which they are well insulated, and a current conducting member for bridging the terminals. The conducting member may be in the form of a fuse, carried within a fuse cartridge, as shown in the accompanying drawings, or may consist of a strip of metal, for example, copper, in which case my device is a non-fusing, disconnecting switch. With either construction, the conducting, or bridging member is adapted to be hingedly supported so as to permit of its being swung into and out of engagement with the terminals, and thus complete, or break the circuit. Further, a novel hinge construction, to be hereinafter described, allows the bridging member to be completely disengaged and removed from the terminal assembly, and yet precludes the unintended, or accidental removal of that member. The removability of the bridging member from the terminal assembly permits safe handling during the process of replacing a destroyed fuse in the fuse.cartridge. The bridging member is usually inserted into and removed from the terminal assembly, by means of a puller stick, or other appropriate appliance.

While I have shown and described a bridging or connecting member in the form of a fuse and fuse cartridge of the expulsion type, it will be obvious that any form of bridging member, either fusible or non-fusible, may be employed, and will fall within the scopeof my invention.

An object of my invention is to provide a disconnecting switch having a blade, and an improved mounting for the blade to permit removal thereof from the terminal assembly. The improvements referred to are directed toward the prevention of casualpr accidental disengagement of the blade from the terminal assembly.

Anotherobject of' -iny invention is to provide locking means, in addition to the frictional means afforded by terminal contacts, for maintaining the switch in closed position;

A further object of my invention lies in the pro vision of improved terminal contacts, whereby a positive and full surface contact with complementary portions of the blade, is obtained.

Further objects and advantages will appear from the following detailed description and the accompanying drawings, in which Fig. l is a side elevation showing a preferred embodiment of my invention; Fig. 2 is a side elevation, partly in section, showing a preferred arrangement for hinging and looking a fuse cartridge; and Fig. 3 is a partially sectioned, end elevation illustrating a terminal assembly in detail.

Referring by numerals to the drawings, a base 4, of suitable material, is adapted removably to support and 'position insulators 5 and 6, as by threaded engagement of studs 7 with portions 8 of the base 4, or by the use of separate nuts 9, as shown. Projecting from the opposite end of each insulator, are 'studs 10, which may threadedly engage angulate adaptor brackets 11 and 12, and which may be secured thereto as by nuts, as shown. These brackets are preferably of dis- 7) similar construction, the chief difference being that the bracket 11 is provided with a relatively shorter intermediate portion 13 than the corresponding portion 14 of the bracket 12. By this construction the fuse cartridge 15 is given an angular disposition (see Fig, 1) which prevents the collection of moisture in the fuse cartridge.

The base, brackets and insulators are made readily separable, and the connections between these parts are preferably uniform, whereby changes in disposition of the insulators may be readily effected. For example, the insulators may be replaced at will, or may be turned end for end, so that the petticoats project downwardly when the assembly is mounted in any position.

Terminal contact structures 16 and 17 are held I securely upon the brackets 11 and 12 by means of bolts 18 which engage base blocks 19. Lugs 20, preferably integral with the base-blocks, and provided with set screws as shown, are adapted to secure the line wires (not shown).

The strips are preferably of suflicient length to provide a bend, indicated at -22, which gives the contact shoes 23 a freedom of movement ordinarily not obtained by a straight element. Each contact shoe is provided with a boss or stud 24, by means of which the shoe is attached to its supporting member. Disposed between each shoe and shoe support, is a semi-resilient guiding member 25, which is secured to the base block as by a rivet 26. The guiding members are provided with apertures 27, through which the studs 24 extend, the apertures being of such size as to permit free movement, side wise, as well as movement normal to the guiding strip. Further means for guiding the contact shoe and restricting a rotational movement thereof, is provided in the projections 28, adapted to angularly position the shoes relative to the guiding member. It will be seen that the described supporting means for the'contact shoes obviates any necessity for niceties of alignment between the shoes and the switch blade pore tion. Since the contact shoes are floa-tingly supported, and effectively self-aligning with respect to the engaging blade contact portions, a full and effective contact area is assured at all times.

The cartridge hinge construction is described and claimed in my copending application, Serial No. 472,999, filed August 4, 1930, but for purposes of completeness, may be described as follows.

A hinging member, indicated generally at 29, is preferably madeseparable fromthe terminal assembly, being secured thereto as by the bolt 18. A pair of spaced arms 30, having hook ends 31, provide a pivot seat which engages the cartridge by means of the pins 32, extendingtransversely therefrom. As an aid in placing the pins 32 in the pivot seat, I provide the guide members 33.

A fin, or cam 34, disposed on the cartridge, cooperates with a guard 35 of the hinge assembly and prevents removal'of the pins 32 from the arms 30, unless the cartridge is in a definite position relative to the switch assembly. The cartridge maybe removed by, first swinging it into open position until a notch or indent 38 in cam 34 lies adjacent the guard 35. A translatory motion of the cartridge may then be effected, and the pivot pins 32 slipped out of the seats. The notch 38 is so disposed relative to the guard 35, that casual or accidental separation of the switch blade from the assembly is impossible, no matter in what position the switch assembly may be mounted. For example, when the base is disposed above the blade portion, and the latch (hereinafter described) is disengaged, it is impossible with the present construction for the blade portion, in assuming a swinging position, to disengage itself by separation of the pins 32 from the arms 30.

By way of illustration, I have shown the terminal assemblies connected by a fuse cartridge, preferably of the expulsion type, which comprises a tube 39, of insulating material having a metal contact at each end and adapted to be engaged by the contact shoes 23, described above. One of the contacts or cartridge terminals 40 is provided with an exterior binding post 41, to which one end of a fuse 42 is secured. The fuse extends through the tube and is fastened at its other end to the cartridge terminal 43 by means of an interior binding post 44. The terminal 43 I is adapted to be closed as by a threaded cap 45 which may be removed to gain access to the binding post 44.

As a means for preventing the cartridge from being blown or jarred out of the terminal assembly, an event liable to occur by reason of a severe fuse explosion under a heavy short circuit, I provide a locking device which maintains the switch in closed position against any force ex cept that which isfdefinitely intended to open the switch. The locking device, which I prefer to mount on the free, or unhinged end of the blade or cartridge, is fully described in my Patent No. 1,903,455 of April 11, 1933, and comprises a pair of spaced latch members 46, only one of which is shown, terminating in hook portions 47 and arranged for pivotal movement about a pin 48. The hook portions 4'7 are adapted to engage shoulders 49 of the contact shoes when the switch is in closed position. While the latch members 46 may be mutually separate, I prefer tolink them together by means of the cross member 50, and I provide a resilient metal strip 51, or other suitable biasing member, to keep the hook portions i? in position to engage the shoulders 49. A manipulating member 52, preferably in the form of a 'ring, is provided with an extending portion 53, whereby it is pivotally supported, between the latch mam;- bers 46, by the pin 48. It may be readily observed that an outward pull on the ring, in opening the switch, causes a movement of the latch member to rotate the hook portions clear of the shoulders on the contact shoes.- In closing the switchin the usual manner and by means of the actuating ring, the latch member is initially cammed outwardlyto clear the cooperating shoulders 49, and are then urged inwardly, under the action of the spring into engagement with the recited shoulders. Obviously, were the latch and ring members constructed integrally, an inward or closing force on the ring, would tend to prevent the hook portions from sliding over the shoulders on the contact shoes, for subsequent engagement therewith.

As will be seen from the preceding description, the provision of uniform securement means between the base, insulators, adaptors and base blocks, facilitates any necessary renewals of any of these members, enables the ready substitution of parts of the same or diiferent size, such as larger or smaller insulators; and the ready interchangeability of all parts, minimizes the supply of spare and stock parts to be maintained, to provide a wide range of capacities and sizes of switches. The assembly as a whole is, moreover, of a rugged type, and inexpensive of manufacture.

While I have described and illustrated a specific embodiment of my invention, it will be understood that alterations and changes in details of construction may be made, without departing from the full scope of the invention.

I claim as my invention:

1. A self-aligning contact structure for electric switches comprising a base member, a pair of substantially parallel, semi-rigid supporting strips secured at opposite sides of the base member, said strips being aperturednear the free ends thereof, contact shoes carried by said strips, each. of said shoes having an integrally formed stud projecting through, and freely movable in the aperture of its associated strip, and a pair of flexible current conducting strips disposed exteriorly of said supporting strips, each of'said conducting strips being permanently secured at one end to the base member, and at the o'ppositeend to the outer end of said stud.

-2. A self-aligning contact structure for electric switches comprising a base member, oppositely disposed contact shoes, a semi-rigid supporting strip for each shoe, said strip being secured at one end to the base member and having an aperture near its opposite end for receiving a stud formed integrally with said shoe, said stud projecting through, and being freely movable in the associated strip aperture, means on said shoe projecting at opposite sides of the strip member for limiting angular movement of the shoe relative to the supporting strip, and a pair of highly flexible conducting elements disposed exteriorly of said strips, each of said elements being permanently secured at one end to the base, and at the other end to the outer end of the stud of .its associated contact shoe.

3. A self-aligning contact structure for electric switches comprising a terminal base,- a pair of substantially parallel contact shoe guiding and supporting members projecting from opposite sides of the terminal base, each being permanently secured at one end to said base, said memigesepae bar for limiting the lateral, or transverse movement of the contact shoe relative to the supporting member, and a highly flexible conductor strip extending between and permanently connected to the outer end of said stud and said terminal base, said conductor strip having an outwardly bowed portion intermediate its ends for increasing the flexibility thereof.

WALTER A. HEINRICH.

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