Patent Publication Number: US-3879590-A

Title: Pneumatically actuated electrical switch

Description:
United States Patent 1191 Kovacs 1 1 Apr. 22, 1975 PNEUMATICALLY ACTUATED ELECTRICAL SWITCH [76] Inventor: Otto Attila Kovacs, 6 Crown Hill Pl., No. 301, Toronto, Ontario, Canada 221 Filed: Apr. 2, 1973 211 Appl. No.: 347,051  
 [30] Foreign Application Priority Data Apr. 26. 1972 Canada 140590 [52] US. Cl. 200/83 P; 200/67 DB; 200/83 C [51] Int. Cl. H01h 35/40; H0lh [58] Field of Search..... 200/81 H, 83 P, 83 C. 83 Z, 200/76, 67 DB, 153 G, 166 CT [56] References Cited UNITED STATES PATENTS 3,109,901 11/1963 Strauss 200/67 DB 3.524.028 8/1970 Barney 200/166 CT X 3.545.125 12/1970 Okuma 200/81 H UX 3,573.410 4/1971 Budzich 200/83 P 3,582,584 6/1971 Best 200/67 DB FOREIGN PATENTS OR APPLlCATlONS 8/1912 France 200/83 C Primary E.ranzinerRobert K. Schaefer Assistant ExaminerGerald P. Tolin Attorney, Agent, or F irm- Lewis B. Hanley [57] ABSTRACT A remotely controllable electrical switch, in which a toggle, pivotably anchored at each end in a resilient mount, is selectively movable by means of a fluid expandable and collapsible bag between two stable positions across a line passing between the anchored ends of the toggle. In one of the two positions the toggle bridges a pair of spaced electrical contacts to close a circuit. The bag is connectable with remote fluid pressure means, preferably a control terminal having a corresponding bag compressible to transfer the fluid contents to expand the bag in the switch.  
 11 Claims, 6 Drawing Figures PNEUMATICALLY ACTUATED ELECTRICAL SWITCH This invention relates to a remotely controlled air pressure electrical switch.  
  Electrical switches presently in use, such as light switches, are connected by wires to remote control terminals having toggles or other movable elements. Such terminals may be located in hazardous areas where sparking could be dangerous.  
  It is an object of the present invention to provide an improved, air-operable electrical switch which is remotely controlled and has no metal contacts at the control terminal.  
  Example embodiments of the invention are shown in the accompanying drawings in which:  
  FIG. 1 is an exploded perspective view of an electrical switch;  
  FIG. 2 is an exploded perspective view of the remote control terminal of the switch of FIG. 1;  
  FIG. 3 is a perspective view, partly broken away, showing the electrical lead connections of the switch of FIG. 1;  
  FIG. 4 is a schematic view of the switch and control terminal of FIGS. 1 and 2 showing the switch in the OFF position;  
  FIG. 5 is a view similar to FIG. 4 showing the switch in the ON position; and  
  FIG. 6 is a schematic view of the switch of FIG. 1 controlled by two of the remote terminals of FIG. 2, one terminal having a two-way toggle to provide a three-way switch.  
  The example embodiment seen in the drawings consists of an electrical switch 10 (FIG. 1) having a control terminal 12 (FIG. 2). Switch 10 comprises a housing 13 of non-conductive material having a removable top 14, a side wall 16, a removable side wall 18, and walls 20, 22 and a bottom 24, all forming an enclosed chamber 26. As seen in FIG. 3, inner surface 28 of side wall 16 is a shallow, V-shaped vertical channel with an offset vertical recess 30 rectangular in cross-section accommodating at one end a terminal bracket 34 and a terminal post or screw 36. A blind passage 38 leads from end wall and is intersected by recess 30. End wall 20 carries a clip 40 on its outer surface adjacent the entrance to passage 38.  
  The inner surface of each end wall 20, 22 carries a vertical strip 42 of resilient material, such as rubber, recessed into the wall. A toggle 44, having a vertical pivot pin 46, is centrally disposed in chamber 26 and each end of the toggle carries a rib 48 at least partially embedded in strip 42. Toggle 44 is so set in strips 42 that the toggle is unstable if it is lying in a plane and in such a position the reactive force exerted by the resilient strips will urge the toggle out of the plane. A flexible, inflatable and collapsible bellows or bag 50 of rubber or other air impervious material is positioned in chamber 26 between toggle 44 and side wall 18, i.e., on that side of toggle 44 opposite side wall 16. One side of bag 50 is connected by one or more eyes 51 to pivot pin 46 of toggle 44 and the other side of the bag is connected through an aperture 52 in side wall 18 to one end ofa gasket 53 lying against the side wall. A flexible, air impervious conduit 54 is connectable by gasket 53 6 to bag 50. Toggle 44 carries a cross-piece in the form of an electrically conductive vertical contact strip 58 on that side of the toggle opposite bag 50 and the strip is positioned to lie in recess 30 when the toggle is moved adjacent inner surface 28 of side wall 16.  
  Control terminal 12 of FIG. 2 comprises a V-shaped housing 60 having a rearwardly downward sloping upper wall 62, a lower rearwardly upward sloping wall 64, side walls 66 (one side wall being removable) and a removable front cover 68 with a vertical slot 70, all forming a chamber 72. A lever 74 is pivotably mounted at one end on a wedge 76 at the back of chamber 72 and projects out of housing 60 through slot 70. A flexible, inflatable bellows or bag 78 is positioned in chamber 72 between lever 74 and lower wall 64. One side of bag 78 is connected by an eye 80 to a pivot pin 82 on lever 74 and the other side of the bag is connected through an aperture in lower wall 64 to one end of a gasket 83 lying against the lower wall. Conduit 54 is connectable by gasket 84 to bag 78.  
  Switch 10 is connectable in an electrical circuit 85, as seen in FIG. 3, by connecting one lead 86 by terminal screw 36 to terminal 34 and by inserting the other lead 88 into passage 38 in side wall 16, lead 88 being secured in passage 38 by wedging the insulated portion 90, behind lead 88 into clip 40 on end wall 20 of housing 13.  
  In the operation of the example embodiment a constant volume of air is trapped in the space within bags 50 and 78 and interconnecting conduit 54 with one bag collapsed and the other bag inflated. When bag 50 is collapsed, switch 10 is in the OFF position and bag 78 is inflated, as shown in FIG. 4, with strip 58 remote from recess 30. When lever 74 is moved laterally against bag 78 it collapses that bag, causing bag 50 to be inflated by shifting the fixed volume of enclosed air. The pressure exerted by inflating bag 50 moves toggle 44 against the reactive force of resilient strips 42 transversely across a line joining ribs 48 into a position adjacent inner surface 28 of side 16, causing contact strip 58 to move into recess 30 and bear against terminal bracket 34 and lead 88, whereby circuit is closed, as seen in FIG. 5. The reactive force of strips 42 maintains toggle 44 in this ON position. To open circuit 85, lever 74 is moved laterally in a direction away from bag 78 which causes that bag to become inflated. As bag 78 is inflated the attendant collapse of bag 50 pulls toggle 44 away from wall 16 towards wall 18, breaking the contact made by strip 58, as seen in FIG. 4. The force exerted by the collapse of bag 50 pulls toggle 44, against the reactive force of resilient strips 42, across a line joining ribs 48 into a stable OFF position.  
  The use of the invention to form a three-way switch is shown in FIG. 6. In this embodiment two terminals 12a and 12b are used. Terminal 12a has a single bag 78 as in FIG. 2 and terminal 12b has a pair of bags 78a, 78b disposed one on each side of toggle 74. Bag 78a of terminal 12b is connected, as before, by conduit 54 with bag 50 of switch 10 and bag 78b is connected by a second conduit 54a with bag 78 of terminal 12a. By this construction either toggle of terminal 12a or 12b may be used to actuate switch 10.  
 I claim:  
  1. A remotely controllable electric switch, comprising:  
 a housing;  
 at least two spaced electrical contacts;  
 a toggle anchored pivotably at each of its ends in resilient mounting means positioned on two first opposed walls of the housing, the toggle being movable across a line through said ends into a position of rest on either side of said line, said toggle comprising a pair of rigid strips interconnected by pivot means, each strip terminating at its free end in a rib lying in the plane of the strip and embedded at least partially in the resilient mounting means;  
 fluid actuable means selectively expandable and collapsable, said fluid actuable means being connected with the toggle for movement of the toggle into either of said positions of rest;  
 the contacts and the fluid actuable means being mounted in the housing on two second opposed walls of the housing normal to said first opposed walls;  
 the toggle carrying an electrically conductive member bridging the contacts in one of said positions of rest of the toggle.  
  2. A switch as claimed in claim 1 in which the fluid actuable meanscomprises an air impervious bag connected with the toggle and fixed on the housing, and air conduit means leading from the bag through the housmg.  
  3. A switch as claimed in claim 1 in which the fluid actuable means comprises an air impervious bag connected with the pivot means of the toggle the bag having a gasket fixed through an aperture in the housing and connectable with conduit means.  
  4. A switch as claimed in claim 1 in which the contacts are mounted in a channel in one wall of the housing and the electrically conductive bridging member is receivable in the channel to bear against the contacts in said one position of rest of the toggle, one of said contacts comprising a bracket having a terminal post, a passage leading into said one wall from outside the housing and intersecting the channel whereby an electrical wire lead is insertable into the channel to form the other of said contacts.  
 5. A remotely controllable electric switch, comprising:  
 a first housing and a second housing;  
 at least two spaced electrical contacts in said first housing;  
 a toggle anchored pivotably at each of its ends in resilient means on two first opposed walls of said first housing and movable across a line through said ends into a position of rest on either side of said line said toggle comprising a pair of rigid strips interconnected by a pivot pin, each strip terminating at its free end in a rib lying in the plane of the strip and embedded at least partially in the resilient mounting means;  
 first fluid actuable means in said first housing selectively expandable and collapsible, said first fluid actuable means being connected with the toggle for movement of the toggle into either of said positions of rest, the toggle carrying an electrically conductive member bridging the contacts in one of said positions of rest;  
 said contacts and said first fluid actuable means being mounted in said first housing on two second opposed walls of said first housing normal to said first opposed walls;  
 second fluid actuable means in said second housing connected by conduit means with said first fluid actuable means between said two housings, and means selectively to expand and collapse the second fluid actuable means.  
  6. A switch as claimed in claim 5 in which the means to expand and contract the fluid actuated means comprises a lever pivotably mounted in said second housing, the second fluid actuated means being connected to a wall of said second housing and to the lever.  
  7. A switch as claimed in claim 5 in which the first fluid actuable means comprises an air impevious bag fixed on the first housing, and the second fluid actuable means comprises an air impervious bag fixed on the second housing, and air conduit means interconnecting said two bags.  
 8. A switch as claimed in claim 5 including means interposed in the conduit means selectively (a) to expand the first fluid actuable means and collapse the second fluid actuable means and (b) to collapse the first fluid actuable means and expand the second fluid actuable means.  
  9. A switch as claimed in claim 8 in which the interposed means comprises a third housing, third and fourth fluid actuable means in the third housing connected by said conduit means with said first and second fluid actuable means respectively, and means selectively to (a) expand the third fluid actuable means ancl collapse .the fourth fluid actuable means thereby collapsing the first fluid actuable means and expanding the second fluid actuable means and (b) collapse the third fluid actuable means and expand the fourth fluid actuable means thereby expanding the first fluid actuable means and collapsing the second fluid actuable means.  
  10. A switch as claimed in claim 9 in which the means to expand and contract the third and fourth fluid actuable means comprises a lever pivotably mounted in the third housing, the third and fourth fluid actuable means being connected to opposite sides of the lever and to opposing walls of the housing.  
 11. A switch as claimed in claim 9 in which the fluid actuable means each comprises an air impervious bag. l