US1495638A - Mechanical switch - Google Patents

Description

e. FUSSNER MECHANICAL SWITCH,

Filed June 9, 1921 2 sinus-sheet 1 Snow doc Patented May 27, 1924.

UNITED STATES PATENT OFFICE.

GEORGE FUS SNER, F MENOMINEE, MICHIGAIN ASSIGNOR TO SIGNAL ELECTRIC MFG. 00., A CORPORATION OI MICHIGAN.

MECHANICAL SWITCH.

Application filed June 9,

To all whom it may concern:

Be it known that I, GEORGE FUssNER, a citizen of the Republic of Germany, and resident of Menominee, in the county of Menominee and State of Michigan, have in vented certain new and useful Improvements in Mechanical Switches, of which the following is a specification.

My present invention relates to electrical switches. The invention is more particularly concerned with switch constructions for effecting circuit connection with either of two alternate groups of apparatus, although some of the broader features of the invention are of wider application for effecting circuit connections at will to any one of a greater number of groups of apparatus. In

the most specific application, the invention relates to switches commonly known as aerial changeover switches for wireless telegraph installations, that is, to two-way switches designed, in one position to effect connections for transmission and in another position for receiving.

It is an object of the invention to provide a switch of the above type which shall have relatively small overall dimensions, which shall have few and inexpensive parts easily assembled and which shall be substantially proof against sparking or creeping over of the high tension current to low tension contacts.

It is another object of the invention to provide a switch of the above type which shall be easy to manipulate and which shall require little or no attention in use;

A preferred feature of the invention is the use of a switch spindle mounted substantially in the plane of an insulating plate carrying contacts upon opposite surfaces thereof, the switch arms which are rotatable with the spindle extending along opposite surfaces of the insulating plate. In the preferred construction, the switch blades at the opposite surfaces extend at an acute angle with respect to each other, so that the spindle operating member, preferably a knob, need be turned through but a small angle to shift the switch from one to the other opera-- tive connection.

Since the stationary contacts for the two alternative circuit connections are upon opposite surfaces of the insulating plate, the danger of sparking over is effectively elimi- 1921. Serial No. 476,118.

nated, without the use of s ecial insulating appurtenances. Moreover, t e ran e of rotation of the knob is automatically imited in each direction by the engagement of a switch arm with its contact, eliminating the need for special stops.

In the accompanying drawings in which is shown one of various possible embodiments of the several features of the invention,

Fig. 1 is a plan View of a preferred form of the invention,

' Fig. 2 is a side view thereof,

Fig. 3 is an end view thereof,

Fig. 4 is a fragmentary sectional view taken along the line 4-4 of Fig. 1,

Fig. 5 is a plan view of the switch blade contacts.

Fig. 6 is a sectional view taken along the line 6-6 of Fig. 5, and:

Fig. 7 is a detail view of one of the stationary contacts.

Similar reference characters refer to similar arts throughout the several views of the rawings.

Referring now to the drawings, I have shown a switch unit comprising an insulating base 1 having an upstanding or vertical contact supporting insulating plate 2 mounted thereon preferably secured thereto by screws 8 extending upwardly from the base into the lower edge of the insulating plate. Resting upon the upper edge 4 of the vertical wall and extending along the length thereof, there is preferably provided a 'jects beyond the bearing at one end thereof as at 8 and preferably carries a collar 9 carrying a switch member 10 having alonger arm 11 projecting outwardly toward one side thereof and a shorter arm 12 projecting outwardly toward the other side thereof, the two arms forming preferably an acute angle with respect to each other, in the specific embodiment shown, and angle of 45. Although the switch member 10 may be made of an integral stamping, it is preferred for the sake of economy of material, to form the element in two parts, as shown, the longer switch blade 11 having a struck-up tang 13 fitting into a corresponding depression 14 in the collar, and the shorter switch blade 12 overlapping the first blade and having a the projecting end 8 of the spindle with.

the switch blades toward the side of the bearing end and a separate washer 17 is,

preferably interposed between the bearing end and the adjacent switch blade member. Upon the end 18 of spindle projecting beyond "the opposite-end '19 of thebearin'g, there is"preferablymounted a collar 20carrying a"projec'ting metallic switch support member 21, preferably soldered thereto, a spacing washer 22 being interposed between said extension. piece and the adjacent "bearmy end. Preferably; a compression spring '23 is coiled aboutthe spindle and disposed within a socket 24 in the bearingend 19, the collar 20 being passed o'ver'the end of the spindle and secured in place as by a set screw 25 after the coil spring is applied. The memberQl carries aninsulatin'g arm 26 secured in place by screws 27 and a metal contact 28is applied preferably to the free end of said arm. An insulating operating knob 29 is preferably secured to the end of the spindle '1' by means of ascrew 30'which passes axially through 'the knob and is threaded into the end of the spindle. A pair of dowel pins (not shown) which'fit "into corresponding holes [provided in collar 20 'antlkn'ob 2'9 preventrelative rotation between said members. I

Upon the insulating plate are mounted stationary contactsforcooperation with the movable switch elements described. The shorter knife switch arm 12'co'acts with "a stationary kn'ife switchgjaw "contacteleinent 31. This contact ispreferably formed of two superposed angle plates and 33 secured nearthe upper end ofthewall 2 by a screw 34, the binding post for said contact being shown at 35. A similar aw contactelement 3'6 'havin'g a binding post" 37 is mounted upon the opposite surface 38 ,of the vertical Wall and near-"the lower end thereof for coaction with the longer knife switch blade 11. The stationary contact for coaction with the contact 28 consists preferably of a pair-of angle plates 39 and 40 secured'in place by screws as at ll and spaced from each other" as at 42 to afford a gap into which the switch contact element 28 can enter thus. effecting albridging connection between them. The contacts 39 and 40 are equipped with binding posts-43 and 4% respectively. j

H In the application ofthe specific switch *des'cribed toits preferred use in Wireless telegraph stationsrit' will be understood. that "bindi'ngpost ll,. for instance, would be connected to on e'sid e" of the power circuit, bindingpost- 43 to the' adjohiing'coil of the transto the antenna.

fortmer binding post 35 to the secondary coil of the oscillation transformer and binding post 37 to the primary coil of the receiving apparatus. The connection to the antenna both for transmission and receiving is preferably made through a binding post 45 mounted directly upon the bearing mem- To set the apparatus for transmission it is merely necessary to turn the knob 29' in the counterclockwise direction the high tension or transmitting current will pass from binding post 35', through'j-aw contact 31 to knife switch blade 12, through collar) into spindle T'to'thebearin'g'memher 5 from the spindle to thebearing even'though the fit benot a tight one. Asthe spring 24 urges the switch blade member 11 -12 against "the end 17 of the bearing element, some of the current may also pass to the bearing at this point.

In order to shiftfron'i'the sendingto'the receiving connection, the knob wouldbe rotated in a clockwise direction to its limit.

This would disengage the contact-arm 26 and knife switch blade 12 "and bring the knife switch blade 11 into coaction 'with the corresponding jaw contact element 36 asbest shown in Fig. 3. lVith this connection, the energy received will be transferred to the binding post 45, through the bearings and spindle '7 to the switch arm 11, jaw contact eleinent 36 and tothe'binding post'37-to which the receiving apparatus is connected.

It will beseen-that the high'tension current cannot reach the low tension contact 28,the substantial length of the insulating the said contact. It will furtherbe seen that the entire thickness of the insulating plate or wall intervenes between the stationary transmitting contacts and the stationary receiving contacts, so that there is and thence through binding post 45. The transmitting current "because of its highten'sion will readily pass arni 2 6 intervening between the bearing and of any sort is required, the thickness of the carrying wall alone effectively performing the insulating function.

It will be seen that the high tension contact 31 and the low tension contact 394L0 for the transmitting circuit are arranged at a material distance from each other, being substantially at diagonally opposite corners of the insulating wall 2, so that the path between them is too long for jumping over. If desired, as an additional precaution, the plate may be formed with one or more integral upstanding insulating ribs between said two contacts to increase the length of the creepage path although, in practice this is, in general, found a needless precaution.

Since the knife switch contacts 1112 form a small acute angle with respect to each other, in the preferred embodiment about l5 degrees, it is apparent thatthe maximum range through which the operating knob need or can be rotated is but an eighth of a complete turn which is effected by a short turn of the hand, whereas, switches that require rotation of their knobs through 90 degrees or more, are generally, relatively diliicult to handle, since this greater angle cannot be traversed in a single operation without substantial strain upon the wrist.

It will be seen that when the switch is turned to either of the two operative positions, the knob is limited against rotation beyond that position, the blade members being arrested by the insulating wall or by the sta tionary contacts thereon against further movement. Thus, the switch in every case is limited against movement beyond closed position and this even in the absence of the special stop means rendered desirable in constructions in which the switch blade moves along the surface of the stationary contacts instead of at right angles thereto.

The stationary jaw contacts extending vertically along a vertical wall, dirt or dust that may otherwise tend to accumulate between the jaws will readily drop out by gravity.

Although the preferred embodiment especially when applied to aerial changeover switches, is in the form of a hand-operated, simple, mechanical switch, it will be under stood that the invention may be embodied in a snap switch construction, which may be operated either by hand or by electromagnetic or other means.

It will be seen that although I prefer to dispose the spindle in horizontal position as shown, many of the features of the construction can be carried out with a vertical or inclined spindle.

Obviously, the invention could be carried forward to the use of more or less than the number of switch blades shown and some of the features could be applied in relations providing for more than two alternative operative settings.

I claim In an electric switch, in combination, a bearing, a spindle extending therethrough, metallic collars carried by the opposite ends of said spindle and beyond said bearing member, a knife switch blade secured to one of said collars at the side thereof adjacent the bearing, a switch arm secured to the other collar at the side thereof adjacent the bearing, and coil spring means encircling said spindle and disposed within a socket in one end of said bearing to yieldingly hold said spindle against movement longitudinally of said bearing.

Signed at Menominee in the county of Menominee and State of Michigan 'this sixth day of June A. D. 1921.

GEORGE FUSSNER.

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