Patent Publication Number: US-3875353-A

Title: Multistage switch assembly having radial contacts axially bridging successive printed circuit board contacts

Description:
United States Patent 1 Mardach I MULTISTAGE SWITCH ASSEMBLY HAVING RADIAL CONTACTS AXIALLY BRIDGING SUCCESSIVE PRINTED CIRCUIT BOARD CONTACTS [75] Inventor: Lahib Mardach, Nuremberg.  
 Germany [73] Assignee: Franz Sieradzki. Nuremberg.  
 Germany [22] Filed: Dec. 26, 1973 [Zll Appl. No.: 428.095  
 [30] Foreign Application Priority Data Jan. I7. I973 Germany 2302048 [52] US. Cl 200/8 A. 200/9. 200/293 [51] Int. Cl. IIDlh 19/56 [58] Field of Search 200/8 A. 8 R. 9, 11 R. 2()()/ll A. II J. ll K. II TW. l4. l6 R. 16  
 B. If) C. l6 D. II DA. 292. 293. 307. 303. 26  
 [56] References Cited UNITED STATES PATENTS 3.592.982 7/1971 Deltocr ZOO/lo D UX 3.683.132 8/1973 Richardson ZOO/ll R 3.735.059 5/l973 Glaser ct al ZOO/l6 C 3.754.IU(1 8/]973 MacDonald BOO/ll DA X FOREIGN PATENTS OR APPLICATIONS (ivrmnnv Illl 3,875,353 Apr. 1,1975  
 OTHER PUBLICATIONS Sophia. Modular Rotary Switch.&#34; Notice Sl070. pp. ll0. date: lO/70.  
 Prinmry E.\&#39;uminer.lames R. Scott [57] ABSTRACT A multistage switch. more particularly for printed circuits. having a substantially cylindrical rotor carrying radially projecting contact elements. contact plates being provided which each close a lateral longitudinal slot of the housing wall so as to complete the internal housing wall surrounding the rotor and have contact strips extending tangentially of the peripheral surface of the rotor. In order to yet further improve the versatility of such a switch with respect to its possibilities of Application but simultaneously ensure a particularly simple structure. the switch is so designed that the rotor can be assembled of a plurality of identical elements which axially succeed one another and each has distributed over its periphery a plurality of recesses for receiving a contact element. the axial structural length of the housing being variable intermediate pieces the length of which corresponds to an integral multiple of the length of the individual elements of the rotor. and the contact elements are of such length that they each connect at least two axially successive contact strips of a contact plate.  
 14 Claims. 7 Drawing Figures MULTISTAGE SWITCH ASSEMBLY HAVING RADIAL CONTACTS AXIALLY BRIDGING SUCCESSIVE PRINTED CIRCUIT BOARD CONTACTS The present invention relates to a multistage switch, more particularly for printed circuits, having in a housing a substantially cylindrical rotor carrying radially projecting contact elements cooperating with substantially parallel contact strips provided transversely of the rotor axis on at least one lateral contact plate, the contact plate or plates being so arranged with respect to the remainder of the housing that they each close a lateral longitudinal slot ofthe housing so as to complete the internal housing wall surrounding the rotor and their surface carrying the contact strips extends tangentially of the peripheral surface of the rotor.  
  It is the object of the invention to so design a multistage switch of this kind which can be made larger or smaller according to requirements. an axis one least said intermediate in According to the invention there is provided a multistage switch comprising a housing having two end pieces, a substantially cylindrical rotor rotatable within said housing about an axis in the form of a plurality of axially sucessive individual elements forming said rotor, at least one longitudinal slot in the housing substantially parallel to said axis, at least one radially protruding contact on each of said individual elements, at least one removable intermediate piece, provided with at least one longitudinal slot for varying the axial length of said housing, the axial length of each said intermedi ate piece corresponding to an integral multiple of the axial length of said individual element, at least one contact plate, transverse to the axis of the rotor and tangential to the rotor, arranged to overlie the longitudinal slot in the housing and tangential contact strips carried by said contact plate and selectively making electrical contact with said radially protruding contact of said rotor, the axial length of said contacts being such as to connect at least two axially successive contact strips of a contact plate.  
  Thus, contrary to the known procedure, the rotor is produced from a plurality of axially successive parts. In this manner it is readily possible, since the housing is simultaneously also suitably subdivided, to adapt the length of the switch, and thus the number of available contacts, to the requirements of the occasion. In this context it is of particular advantage if, in accordance with the proposal of the invention, the contact elements are provided at the periphery of the rotor and the switching operation is on any given occasion effected at one and the same contact plate. In this manner considerable freedom is obtained with respect to fitting of contact elements. Normally there are provided for example six recesses for contact elements on the periphery of an individual part of the rotor, so that, dependent on the actual complementing of the recesses, a multiplicity of switching possibilities already results. Clearly, the number of possible switch positions can, however, be considerably increased when not just six but for example ten or twelve recesses for attaching contact elements are provided.  
  Further details of the invention will become apparent from the following description of a preferred exemplary embodiment of the multistage switch according to the invention reference being made to the accompanying drawing, in which:  
 FIG. I is a side elevation of the rotor of the switch;  
  FIG. 2 is an axial section taken along line IIll of FIG. 3;  
  FIG. 3 is an end elevation (from above in FIG. 1) of an individual rotor element;  
  FIG. 4 is an exploded view of individual elements of the switch;  
  FIG. 5 is a side elevation of a possible embodiment of a contact plate for a switch according to the invention; and  
  FIG. 6 and 7 are a side view and a plan view of the assembled multistage switch.  
  As is clearly apparent from the drawing, the switch according to the invention has a housing, generally designated by the reference numeral 1, assembled from a plurality of individual parts. This housing is provided with a cylindrical bore 2 in which a rotor, generally designated by the numberal 3, is accommodated and rotatable, by means of a shaft 4. The housing is provided along its two longitudinal faces with a longitudinal slot 5 which enables the contact elements 6 of the rotor 3 to engage the contact plates 7 and 7a provided on either side. The contact plates 7 are provided with contact strips 8 and 8a. The contact strips 8 end in terminals 9 serving for connection of the multistage switch with a wiring plate, for example a printed&#34; circuit. As is also clearly apparent from the drawing (FIGS. 4,5) the contact strips 8,8a each extend transversely of the longitudinal axis of the switch and parallel to one another. On the contact plates 7, the contact strips 8 are each individually connected to the terminals or connecting lugs 9. The contact 7a on the other hand is so designed that only half of the contact strips i.e., the contact strips 8, are each individually connected to a connecting lug 9, while the respective contact strips 8a situated therebetween are interconnected and jointly connected to a single terminal 9a.  
  As is clearly shown in FIG. 4 the rotor 3 comprises a plurality of, in principle identical, individual elements 11 the precise design of which is apparent from FIGS. 1 to 3. A plurality of such individual elements are axially pushed onto the rectangular shaft 4 to abut the adjacent element and an end piece 12 abuts the element at one end at least. As a result of the use of, in the illustrated embodiment, a rectangular shaft 4 and a corresponding opening 13 in the individual elements 11 perfect entrainment of the individual elements is ensured when the shaft 4 is turned. The shaft and the opening could, of course, have a different shape. Moreover, in order to enhance the versatility and to increase the number of switching positions of the switch, it is possible to arrange the lateral faces of the opening 13 in the various individual elements at differing angles to the plane of symmetry 15, according to the dot-dash line 14 of FIG. 3, so that the contact elements 6 of adjacent individual elements 11 are relatively offset in peripheral direction, although the angular spacing between the individual openings 16 for receiving the contact elements 6 is the same.  
  FIGS. 1 to 3 show clearly that the openings 16 for the contact elements 6 have the configuration of longitudinal slits which are formed in an annulus l8 upstanding from a bottom 17 of the individual elements. The annulus 18 is formed with an annular groove 20 opening into the face 19 of the individual elements. A substantially cylindrical portion 21, the face 22 of which somewhat recedes relative to the face 19, remains within the annular groove 20. At that side of the individual element 11 which is situated opposite the face 22 a substantially cylindrical attachment 23 protrudes beyond the corresponding face 24 about to the same extent as the face 22 recedes relative to the face 19.  
  In a peripheral wall 25 and substantially centrally of the openings 16 there are provided recesses 26 for the contact elements 6 which recesses are open toward the face 22, as is shown in FIG. 1 in particular. When the individual elements 11 are in the position of use shown in FIG. 4, i.e., when several individual elements 11 axially adjoin one another, then the recesses 26 are closed by the attachment 23 in the region of the face 22.  
  As can be seen in FIG. 3 the contact elements 6 are of substantially U-shaped cross-section. Lateral strips 28 adjoin the legs 27 of the contact elements 6 which are generally bent of sheet metal. In the position of use the strips 28 contact the annulus 18 from inside in the region of the longitudinal slits 16 to retain the contact elements in place.  
  A compression spring 29 holds the contact elements 6 in the position of use and resiliently urges them against the contact plates 7. On end of the compression spring 29 is supported by the contact face 30 of the contact elements 6 and the other end is supported by the bottom of the recesses 26. By virtue of the central disposition of the recesses 26 relative to the longitudinal slits 16 and the recesses 26 being closed by the attachment 23 the springs 29 are virtually precluded from dropping out after assembly. On the other hand it need hardly be explained in detail that the contact elements 6 with the springs 29 can be mounted in simple manner by being axially (from above in FIG. I) pushed into the slits l6 and the recesses 26.  
  FIG. 3 shows an individual element 11 fitted with only a single contact element 6. It is, of course, possible to envisage a different arrangement. Moreover, it is also conceivable to provide a greater or smaller number of openings 16 than the six shown. It is of course, very important for the axial extent of the contact surface 30 of the contact elements 6 to be of such magnitude that one contact element 6 always connects at least two contact strips 8 or 80.  
  In the exemplary embodiment illustrated the housing of the multistage switch includes an end piece 31 (FIG. 4) which is hollow, a second end piece 32 which has an attachment provided with longitudinal slots and a cylindrical bore 2, and optionally one or more intermediate pieces 34 which are provided in pairs. For the purpose of connecting the end pieces, 31,32 to each another and to the interposed pieces 34, and more particularly for mutual alignment of these parts, pins 35 and, of course, corresponding bores which are not shown in the drawing are provided on the end pieces 31, 32 and the intermediate pieces 34. In use the housing of the multistage switch is assembled by plugging together the two end parts 31, 32 and, depending on the number of individual elements 11 of the rotor, optionally also one or more pairs ofintermediate pieces 34. The end plates 36 which simultaneously also serve for securing the switch to a suitable support are then fitted. Finally the end plates 36 are clamped together by means of screw bolts 38 engaging in lateral slots 37 of the end plates 36 and end pieces 31, 32 and nuts 39 threadably applied onto the screw bolts 38, whereby the individual sections of the housing are secured against loosening. Actually, prior to insertion of the screw bolts 38 into the slots 37 the contact plates 7 must be laterally fitted to the corresponding contact surfaces 40 of the intermediate pieces 34 and/or end pieces 31, 32. The contact plates 7 are generally secured in this position by means of some kind of suitable arrangements, e.g., by detent elements.  
  Finally, as is apparent from FIG. 4 of the drawing an indexing mechanism, generally designated by the reference numeral 41, is optionally accommodated in the hollow and piece 31. This indexing mechanism consists of a toothed plate 42 with which resiliently outwardly urged indexing elements 43 cooperate, these being guided in an opening 44 of a drive shaft 45 normally carrying the central knobs. Two toothed rings 46 having protruberences 47 serve for restricting rotation. For this purpose the protruberences 47 cooperate with stops 48 of the corresponding end plate 36.  
  With reference to the above description it follows that according to the invention a multiplicity of switches having the most diverse switching positions and of greatly differing sizes, i.e., differing number of planes, can be constructed. Since the contact elements 6 normally cooperate with one contact plate 7 it is, of course, also conceivable to make the design of the switch such that a contact plate 7 is provided only at one side while the longitudinal slot 5 of the other side is closed, in which case then individual intermediate pieces could be provided rather than pairs of intermediate pieces. It is clear that the axial length of the intermediate pieces should equal an integral multiple of the length of the individual elements.  
 We claim;  
 1. A multistage switch comprising, in combination:  
 a. a housing made up of a plurality of sections;  
 b. two end pieces of said housing;  
 c. a substantially cylindrical rotor rotatable withing said housing about an axis;  
 d. said sections defining at least one longitudinal slot in the housing substantially parallel to said axis;  
 e. a plurality of axially successive individual elements forming said rotor;  
 f. at least one radially protruding contact on each of said successive individual elements forming said rotor;  
 g. at least one removable intermediate piece, provided with at least one longitudinal slot for varying the axial length of said housing, the axial length of each said intermediate piece corresponding to an integral multiple of the axial length of said individual element;  
 h. at least one contact plate, transverse to the axis of the rotor and tagential to the rotor, arranged to overlie the longitudinal slot in the housing; and  
 . tangential contact strips carried by said contact plate and selectively making electrical contact with said radially protruding contact of said rotor the axial length of said contacts being such as to connect at least two axially successive contact strips of a contact plate.  
  2. A multistage switch as claimed in claim 1, and further comprising means defining openings in said individual elements, said openings accommodating said radially protruding contacts.  
  3. A multistage switch as claimed in claim 2, and further comprising means defining an annular groove in each of said individual elements said groove opening into one axial end of the respective element. said openings being formed as longitudinal slits extending between the peripheral surface of the individual element and the annual groove, and a retaining strip carried on the radially inner end of said contacts, said retaining strip engaging the annular groove to retain said contact within its slit.  
  4. A multistage switch as claimed in claim I, wherein the contacts have a substantially U-shaped crosssection and are formed of sheet metal and further comprising a compression spring urging said contact elements radially upwardly of the respective individual elements.  
  5. A multistage switch as claimed in claim 4, and further comprising a recess aligned with the longitudinal slit, the compression springs engaging said recesses.  
  6. A switch as claimed in claim 5, wherein the recesses open towards said one end face.  
  7. A multistage switch as claimed in claim 5, and further comprising means defining a depression in said one face, so that said recesses have an axial length and a circumferential width which is substantially equal, and said other end face has a projection dimension to engage in the depression of an adjacent individual element.  
  8. A multistage switch as claimed in claim 1, wherein the individual elements each have a polygonal opening for insertion of a corresponding polygonal shaft.  
  9. A multistage switch as claimed in claim 8, wherein the individual elements all have openings of identical configuration, but the angular position of this polygonal opening of one element, differs from that of another.  
  10. a multistage switch as claimed in claim 1, wherein the intermediate pieces of the housing are each formed as two separate blocks having an arched inner surface.  
  11. A multistage switch as claimed in claim 10, wherein the intermediate pieces each have two parallel lateral contact surfaces for the contact plates.  
  12. A multistage switch as claimed in claim 1, wherein the intermediate pieces of the housing further comprise on one end face thereof a projection, and on the other end face thereof a bore to receive the projection of an adjacent intermediate piece.  
  13. A multistage switch as claimed in claim 12, and further comprising lateral clamping bolts adapted to draw the end pieces of the housing towards one another on an axial direction.  
  14. A multistage switch as claimed in claim 1, and further comprising indexing means accommodated in one end piece of the housing.  
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