US758120A - Switch. - Google Patents

Description

No. 758,120. j PATENTED APR. 26, 1904;,l

' H. TRUMBUL'L.

SWITCH.

Y ABPLIQATION- FILED JULY 18, 190 &. .H0 IODEL. Y

'TT lil 3 i!!lllIIIIIIllllllllIlllllllllllllllll UNITED STATES Patented April 2e, i904.)l

PATENT OFFICE,

HENRY TRUIVIBULL, OF PLAINVILLE', CONNECTICUT, ASSIGNOR TO THE TRUMBULL ELECTRIC COMPANY, OF PLAIN VILLE, CONNECTICUT, A

CORPORATION OF CONNECTICUT.

SWITCH.

SPECIFICATION forming part of Letters Patent No. 758,120, dated April 26, 1904.

. Application ltiled July 18, 1903. Serial No. 166,206. (No model.)v i i To @ZZ whom t may cori/cern: l i l. Be it known that I, HENRY TRUMBULLa citizen of the United Statesand a resident of Plainville, in the county of Hartford and StateV of Connecticut, have invented certain new and useful Improvements in Switches, of which the following is a specification.

The invention relates to the class of devices commonly used in the art for controlling electric circuits, and pertains more particularly to the special class of devices known as knifeswitches.7 In such devices it has been a com'- n mon practice to provide a blade or knife, or a pair vof blades, hinged at one end to a pair of terminalsand adapted to be brought into contact with cooperating terminals at the opposite end, in such devices the terminals having been ordinarily made of metal and joinedby screws or other means to a binding-post section to receive the line-wire.

The object of the present invention is to ,proyide a simple, inexpensive, and compact device pertaining more particularly to the stationary contacts which cooperate with the blade of the switch and at the same time'to provide perfect carrying capacity for the .connections between the binding-post and switch' terminals.

' A further object is to produce a combined terminal and A switch-contact that is made from a single piece of metal, which may be readily secured in place and which will give a perfect contact with the blade of the switch. l v

A still further object is to produce a stop device which may be used in conjunction with the stationary contacts and which will deter-V mine the depth to which the movable blade or Vcontact may be inserted in the stationary con-l tact.

Referring to the drawings, Figure 1 is a perspective view of a switch embodying the improvements. Fig. 2 is a perspective view of one of the knife-switch contacts. Fig. 3 is a rear elevation of the contacts shown in Fig. 2, showing the stop. Fig. 4 is a modified form of contact with outwardly-turned ears in place of the inwardly-turned ears shown in Fig. 2. Fig. 5 is a view in elevation of the contact shown in Fig. 4, illustrating the stop. Fig. 6 'illustrates a lvertical section of the knifeswitcli contact and terminal attached thereto,

the parts being separated to better illustrate Y the construction. Fig. 7 is a plan view of the Y parts shown in Fig. 6.

In the accompanying drawings thenumeral 1 denotes the base or support, of insulating material, which may be made from any suitable non-conducting material, and 2 3 designate clips or contacts in which the movable blades 4 5 are pivoted.. These bladesare joined together at one end by 'a cross member 6, to which is secured an ordinary'handle for throwing the blades 4 5 into and out of contact with the contact members 7 8. It is to be noted that in each of the contact members 7 and 8 and 2 and 3 a single piecek of metal forms both the contact and the binding-post by which the line-wires are attached.

The contacts 2 and 3, which form the pivotal supports for the bladesut 5,. are substantially' alike, inasmuch as they are formed of a single piece of metal; but in the'case of the contact 3 there is shown a support with upwardly-extending side members which are bent back-v ward and downward upon themselvesforming a very rigid and somewhat thickened support .for the pivot 9. In the case of the contact 2,

which is shown in slightly-modied form,the downward portion has beenomitted; but in either case the binding- post sections 10 and 11 are formed integral with Ythe supporting members 12 13. These combined binding-posts and hinged clips are securedto-the base of insulating material in any desired manner,- as by screws,'and each of the members, adjacent to the point where the line-wires are attached, arev provided with uptiirned ears 14, which se-v I curely hold the end of the Yline-wire in position a spring gripping-jaw for the switch-blades. These clips are secured to the base through the medium of stops 21, which comprise a small block of metal arranged to fit between the side walls of the clip and are provided with an upwardly-extending projection or stop 22, which is arranged transversely to the slot or opening 23,formed between the spring-jaws. This stop is provided with a screw-thread in the section 21, which cooperates with a screw 24 and by which the combined clip and binding-post is secured to the base 1.

The purpose of the stop 22 is to prevent the blades 4 5 passing into the openings 23 to too great an extent, and serve as an indicator to show the operator by the feel of the switch when the blades have been properly inserted in the clips. Y

There are material advantages in forming the clip and binding-post from a single piece of material, as sheet metal, which is bent to form. Absolute contact is insured between the line-wire and the switch-blades, and all of the parts of the clips may be readily formed by dies with little or no waste of material.

In Figs. 4 and 5 of the drawings there is shown a slightly-modified form of clip in which the binding-post section 25 is provided with upturned ears 26 and an opening to receive the binding-screw, as at 27. Integral with this binding-post section are upwardlyextending walls 28, which converge, as at 29,

. and being continued form parallel walls 30 with outwardly-projecting lips 31, the latter arranged to insure proper engagement of the switch-blades. A stop 32 is adapted to be used with this clip, as in the case of the clips above described, and is of the same general formation. There is a special advantage in providing an independent stop in the clips, inasmuch as the contact and binding-post members are usually formed of copper, and the stop may be formed of a harder material, in which a screw-thread may be cut, and which will bear much greater strains than will the soft copper of the clip.

The same advantages above recited may of course be secured in practically the same manner by using the arrangement shown in' Figs.` 6 and 7 of the drawings. In these figures the contact 7 has the side walls 2O and downturned end walls 19, together with the parts 17 and lugs 18, arranged identically as heretofore described; but in place of using a stop having an upturned lug, as illustrated in this construction, inasmuch as the screw 35 serves a double purpose in that it holds the contact to the base and also provides the necessary stop for the blade.

In Figs. 6 and 7 there is also illustrated the preferred form of terminal contact for use in connection with the contact-clips of the switch. These terminal contacts 38 are preferably formed of seamless tubing crushed down at one end, as at 39, and punched, as at 40, to lit over the binding-screw 41. This screw is inserted from below through the base and, cooperates with a nut 42 to hold the terminals 38 in place. the lowest possible cost and insures proper conductance of the current, inasmuch as it may be made of the finest copper. of course is inserted in the open end of the terminal 43 and may be secured therein by soldering or by a set-screw,if desired. It will of course be seen that the body of the contact is made from a single piece of metal with the upturned ears 18 and all of the parts integral, and the crushed tubular terminal member may be easily inserted between the ears 18 and secured in place by the nut and screw.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. A contact for switches comprising a binding-post section and a blade-engaging section formed from a single piece of material bent to shape, an insulating-base and screw for securing said binding-post section to the base and a nut arranged within the side walls of the binding-post section and adapted to be engaged by the screw, said nut having an eX- tended lug upturned to form a stop.

2.- In a switch-contact comprising a bindingpost section and a blade engaging section formed of a single piece of material bent to shape, an insulating-base, a screw for securing said binding-post section to the base and a nut cooperating with said screw and arranged between the side walls of the binding-post section and having an upturned lug forming a stop, said nut formed of a different material from that of the binding-post.

3. The combination of an insulating-base, a switch-contact including a binding-post section and a switch-blade section adapted to be engaged by the switch-blade, the two sections formed of a single piece of material bent to shape,the switch-blade section including in- Such a terminal may be made at The line-wire

Images