US2182715A

US2182715A - Rotary switch

Info

Publication number: US2182715A
Application number: US140705A
Authority: US
Inventors: Louis A Yeske
Original assignee: Arrow Hart and Hegeman Electric Co
Current assignee: Arrow Hart and Hegeman Electric Co
Priority date: 1937-05-04
Filing date: 1937-05-04
Publication date: 1939-12-05
Anticipated expiration: 1956-12-05

Description

Dec. 5, 1 939. YESKE 2,182,715

ROTARY SWITCH Filed May 4, 1937 INVENTOR LOUIS A YESKE BY HI S ATTORNEYS Patented Dec. 5, 1939 UNITED STATES PATENT OFFICE ROTARY swrrcn Application May 4, 1937, Serial No. 140,705

11 Claims.

This invention relates to electric switches and is particularly applicable to rotary electric switches in which'the switch contact movement is controlled by cams, but the principles of the invention are capable of use in other types of switches. More particularly, the invention relates to means for mounting the operating came upon the switch spindle in a, secure and inexpensive manner. The invention also relates to indexing means for maintaining the switch in any one of this plurality of angularly spaced positions.

It is an object of my invention to provide a simple, effective and inexpensive means, for mounting upon a switch spindle the cams or like operating devices which operate the switch contacts. Another object of my invention is to provide an improved and inexpensive means for positioning a switch spindle in any one of a plu-, Other obrality of angularly spaced positions. jects and advantages of my invention will appear as it is described in connection with the accompanying drawing.

In the drawing, Fig. 1 is an elevation view partly in section, through a rotary electric switch embodying the principles of my invention. 'The section is taken along line I-l of Fig. 2;

Fig. 2 is a transverse section view of the in vention shown in Fig. 1 with the section taken along line 22 of Fig. 1;

Fig. 3 is an exploded perspective view showing the switch spindle, the cam holding member and one operating cam;

Fig. 4 is a transverse section view of the switch spindle and cam holding member in one stage of assembly;

Fig. 5 is a view similar to Fig. 4 with the same parts in assembled position.

Referring to the drawing, the movable and fixed contacts and operating mechanism of the switch are mounted upon and contained within a two-part switch casing, preferably made of molded insulation and comprising a base portion 10 and a cover portion l2, each portion being hollowed out for reception of the operating parts of the switch. A switch'spindle II is mounted centrally within the casing and passes through the cover and base. Upon this spindle are mounted four contact operating plates or cam discs l6, i8, 20 and 22, which are axially spaced by means of collars 24. These cam discs are of fibrous or other suitable insulating material and are secured in position upon the shaft by means of a cam holding member designated generally by the numeral 26. This cam holding member is stamped from sheet metal into substantially U- shape having narrow parallel arms it running parallel to the spindle which are joined at one end by a transverse portion 26 This transverse portion has a key-hole shaped aperture, of which the large portion MS is of such size and diameter as to permit the insertion of the spindle I4 therein by axial movement. The spindle I4 is provided intermediate its length with a reduced section l4 adapted to fit within the narrow end 26 of the key-hole aperture in the cam holder, where by the spindle and cam holder are keyed together for rotation as a unit.

The cam discs are each provided with four rectangular openings 22 equally spaced apart around a centrally located aperture 22 the latter being for reception of the switch spindle I4. Opposite ones of the openings 22 are adapted to receive the legs it of the cam holder as the cam discs are moved axially along the spindle H. In this manner each cam disk is compelled to rotate with the cam holder and spindle as the spindle is rotated. In order to support firmly the ends of the legs Mi of the cam holder and to resist a tendency of the cam holding member -to twist out of position an anchor disc 21 is mounted on the spindle I4. This disc has a keyhole slot provided in its central portion to cooperate with another reduced section [4 shortly below themiddle of the spindle in the same manner as the keyhole slot of cam holder 26 does with the reduced section The reduced section I4 however, must extend sufiiciently below the ends of the legs 26 of the cam holder to permit free radial movement of the anchor disc to engage the narrow end 21 of the keyhole slot with the reduced section M after which the disc may be moved axially to engage the legs 26' in rectangular openings 21* provided therefor in the disc. It may now be seen that when the parts are assembled the cams prevent the cam holder 26 and anchor disc 21 from moving radially with respect to the spindle and thus hold the narrow ends Mi and 21 of the key apertures in engagement with the reduced portions M and N of the spindle. When the cams are all mounted upon the spindle and spaced apart by the spacing collars 24 they may be secured permanently in assembled position by spreading the ends of the arms 26 over the bottom face of the anchor shape as the cross-section of this lower flattened Lil end of the spindle whereby the indexing disc and spindle are keyed together. The indexing disc has pressed into its lower surface spherical indentations 30 corresponding in number to the number of positions it is desired to have the switch to take. These recesses receive springpressed ball bearings 32 which are pressed into engagement with the indexing disc by coil springs 35.

The spindle with the cam assembly thereon may be secured in the switch base after proper assembly of the indexing means by peening over the bottom end of the spindle against a washer, or in any other suitable manner.

The particular arrangement, location and means of securing the fixed and movable switch contacts form no part of my invention and therefore will only be described in a general way. In the form of invention illustrated there are 6 wire terminals, four (40, 52, 443, 46) of which are mounted upon the switch base. The

terminals

40 and 42 have upstanding posts Ml and 42 with fixed contacts mounted thereon for engagement and disengagement by movable contacts mounted upon resilient metallic strips Mi fit which are mounted upon'posts bent up from the

terminals

44 and 46. Cams l6 and it operate these movable contacts.

' The two remaining terminals il and 50 are mounted in the cover of the switch casing. The terminal 48 has an upstanding post with fixed contact similar to terminals M and 52. Terminal 50 has two movable contacts mounted thereon, which are subject to operation by the

remaining cam discs

20 and 22 in a manner similar to that just described, for engagement with the contact on terminal 48 and a contact on an extension of the post of terminal 40, respectively.

It will be obvious that the switch may be adapted for movement into any desired number of positions by the proper use and positioning of an appropriate number of indexing balls 32 and a suitable indexing disc 30 with the appropriate number of ball receiving recesses 30' formed therein.

The switch is operated by a handle 52 which is mounted upon the upper end of the spindle in a conventional manner.

In order to prevent destructive arcing in switches in which the contacts are separated comparatively slowly as in the present switch, it has been found desirable to limit the degree of contact separation so that the arc will be short when the alternating current passes through the zero point of its cycle. For example, the limitation of the arc to between approximately 24 and 60 thousandths of an inch for 250 volts alternating current has been found to result in less pitting of the contacts than larger gaps. Arc length lim'tation also practically eliminates the danger of the arc striking into other switch parts as might be done if a long are were drawn.

In order to limit the degree of contact separation and hence the degree of arc length I provide on the inside surfaces of the side walls of the casing fins or

ribs

52, 54 in position to be engaged by the ends of the movable contacts when they. have moved the desired distance from the fixed contacts. The provision of these ribs avoids the necessity of accurate and precise formation and positioning of the cams I6, I8, 20, 22, and

also small variations in the location of the spindle l4 become immaterial.

A switch of this type is not suited to direct current work, due to the fact that the arc gap is limited to a length across which a destructive arc would be maintained at ordinary house lighting and power circuit voltages and currents.

Many modifications within the scope of my invention will occur to those skilled in the art. Therefore I do not limit myself to the precise form of the parts as illustrated.

I claim:

1. In an electric switch, a spindle, having a formation thereon with which holding means is adapted to cooperate, a plurality of contact operating members mounted on said spindle in spaced positions, holding means cooperating with said spindle and being constructed and arranged to move radially into engagement with said spindle, and means rendering said holding means nonrotatable and non-axially movable with relation to said spindle, said holding means engaging with said operating members and holding them permanently on said spindle while being in turn held by said members against radial movement on said spindle.

2. In an electric switch, a spindle having a formation thereon with which holding means is adapted to cooperate, a plurality of contact operating members mounted on said spindle, means spacing said members along said spindle, holding means cooperating with said spindle and being constructed and arranged to slide axially onto said spindle and to move radially into engagement with said spindle and means rendering said holding means non-rotatable and non-axially movable with relation to said spindle, said holding means being engaged with said operating members and holding them permanently on said spindle and being in turn held by said members against radial movement on said spindle.

3. In an electric switch, a spindle, a plurality of contact operating members mounted on said spindle, means spacing said operating members apart, a single securing member engaged with said spindle, and means rendering said member, when so engaged, non-rotatively and non-axially movable relative to said spindle, said member including means extending parallel to said spindle and engaging with said operating members to hold them permanently in position.

4. In an electric switch, a spindle having a non-circular portion, a plurality. of contact operating plates mounted on said spindle in spaced positions, a member having arms extending along said spindle and engaging all said plates and having a portion connecting said arms and engaging said non-circular part qf said spindle, the engagement of said member with said spindle and plates preventing movement. of said member axially and radially relative to said spindle.

5. In an electric switch, a spindle having a portion of reduced section, a plurality of cam discs mounted on said spindle in spaced positions, a member holding said discs against rotation relatively to said spindle, said member being stamped into'U-shape from sheet metal and having a pair of arms parallel to the spindle and passing through said cam discs, a transverse portion joining said arms and having a key-hole shaped opening through the larger portion of which said spindle may axially pass, the narrowed part of said opening non-rotatively engaging the reduced portion of said spindle.

6. In an electric switch, a spindle having a notch, a plurality of contact operating members mounted thereon, means spacing said operating members apart, a member engaging with all said contact operating members to hold them in position upon said spindle, said holding member being slidable radially into said notch and engaging with said notch to hold said contact operat ing members non-rotatively and non-axially movable with relation to said spindle, means rendering said holding member non-radially movable relative to said spindle, when said holding member and operating members are engaged.

7. In an electric switch, a spindle, a plurality of contact operating cam members mounted thereon, means spacing said operating members apart, a securing member non-rotatively engaging with said spindle, said securing member having a portion extending longitudinally of said spindle and engaging with all said cam members to hold them in position upon said spindle, the end of said longitudinally extending portion being deformed to secure said cam members and securing member permanently on said spindle and means interengaging between said securing member and spindle to hold said securing member non-axially and non-rotatably movable on said spindle.

8. In an electric switch, a spindle, a plurality of contact operating members mounted thereon, means spacing said operating members apart, means for securing said contact operating members upon said spindle comprising portions engaging said spindle above and below said contact operating members and a portion extending lengthwise of said spindle and engaging all said contact operating plates to hold them in position upon said spindle, said securing means being deformed to secure said contact operating members and securing means permanently in position on said spindle, and means interengaging between said securing means and spindle to hold said securing means non-axially and non-rotatably movable on said spindle.

9. In an electric switch, a spindle, a plurality of contact operating members mounted thereon, means spacing said operating members apart, means for securing said contact operating members upon said spindle comprising portions engaging said spindle above and below said contact operating members, means including at least one of said portions preventing rotary movement of said securing means on said spindle, said se-' curing means also having a portion extending lengthwise of said spindle and engaging all said contact operating plates to hold them in position upon said spindle, said securing means being deformed to secure said contact operating members and securing means permanently in position on said spindle.

10. In an electric switch, a spindle, a plurality of contact operating members mounted thereon,

means spacing said operating members apart,

means for securing said contact operating members upon said spindle comprising portions e11- gaglng said spindle above and below said contact operating members, means including at least one of said portions for preventing axial movement of said securing means along said spindle, said securing means having a portion extending loigitudinally of said spindle and engaging all said contact operating plates to hold them against rotation relatively to said spindle, said securing means being deformed to secure said contact operating members and securing means permanently in position on said spindle.

11. In an electric switch, a spindle, a plurality of contact operating members mounted thereon, means spacing said operating members apart, means for securing said contact operating members upon said spindle comprising portions engaging said spindle above and below said contact operating members, means including at least one of said portions preventing rotary movement of said securing means on said spindle, and including at least one of said portions preventing axial movement of said securing means along said spindle, said securing means having a portion extending longitudinally of said spindle and engaging all said contact operating plates, said securing means being deformed to secure said contact operating members and securing means permanently in position on said spindle.

LOUIS A. YESKE.