This invention relates to an electric switch of the tell-tale variety, the invention being embodied in a switch of compact structure adapted to be secured to the dashboard of an automobile vehide for any desired use such as the control of an electric motor in a heating unit.
An object of the invention is to provide improvements in details of structure of switches of this type, and to make possible more economical and expeditious manufacture and assembling of such switches.
Other advantageous features will be apparent to one skilled in the art from the disclosure of the invention in the following description and on the drawing of whichFigure 1 is a perspective view of the several parts constituting a switch embodying the invention.
Figure 2 is a longitudinal section of the assembled switch.
Figure 3 is a section on the line 3-3 of Figure 2.
Figure 4 is a sectional view similar to Figure 3, but showing the parts in a different position of operation.
As indicated in Figure 1, the switch may comprise an operating knob 10, preferably of molded translucent material, the knob having a tubular shaft II of brass or other suitable material inserted prior to the molding operation so as to form a substantially integral structure with the molded material. The switch structure also includes a cylindrical housing member 12, preferably of metal which receives loosely a longitudinally split sleeve member 13. A lamp socket 14 is located within the sleeve 13\and is adapted to receive and hold the base of a lamp 16. The sleeve also contains a pair of disks 20 and 21 of insulating material, these disks being pushed apart by a compressed spring 22. The housing member 12 may be externally threaded as at 23 to receive one or more nuts 24 by which the switch may be attached to a dashboard or other support. The rear end of the housing member 12 is closed by a plate 25 of insulating material. This may be secured in place by any suitable device. As shown, the rear portion of the housing member is thinned to form an inner shoulder 26 against which the plate 25 seats, the plate being held in place by end edge portions of the housing member which are crimped or spun over to engage the rear face of the plate as at 27.
The cylindrical housing member 12 is cut away from its rear end as at 28 to form an arcuate edge portion 29. If desired, another such portion may be cut away as at 30 to form a similar arcuate edge 32 diametrically opposed to the arcuate edge 29. Each of these arcuate edge portions preferably terminates at both ends in a shallow notch or depression 34 for a purpose hereinafter explained. The sleeve 13 may be made with two portions of different diameters, the rearward portion 36 having a slightly larger diameter than the forward portion 38. Projecting radially from the rear end of the sleeve 13 is an ear 40 which is adapted to ride on the arcuate edge 29 of the housing member 12 as the sleeve 13 is rotated relative to the housing. If the housing is provided with two cut-away portions 28 and 30, an additional ear 41 may be provided to ride on the arcuate edge 32. The side edges of the cut-outs in the housing member 12 limit the travel of the ears 40 and 41, and hence limit the angle of rotation of the sleeve 13 relative to the housing.
The ears 40 and 41 ride into certain of the notches 34 when the sleeve reaches either of its limiting positions relative to the housing member 12. The edge-engaging faces of the ears 40 and 41 are preferably rounded so as to fit in the notches 34 and to ride easily out of the notches when the sleeve is turned. Since the sleeve 13 is normally pressed forward, as hereinafter described, the engagement of the ears in the notches 34 serves as a yielding detent to maintain the sleeve releasably in one or the other of its extreme positions of operation. Nested within the portion 38 of the sleeve 13 is the lamp socket 14. From the rear end of this socket, a pair of ears 44 and 46 project radially and engage in a pair of slots 48 and 50 in the sleeve 13 so as to hold the socket against rota-tion when a lamp is inserted therein. The socket may be loosely inserted in the sleeve 13 or may be permanently secured therein as by a drop of solder. As illustrated in Figure 1, the socket is designed for use with a lamp having a base with radial pins 52 and a central contact point 54. The pins 52 are adapted to engage in bayonet slots 56 in the socket 14, being held therein by forward pressure from the spring 22. The pressure 4 from this spring is exerted through a cup-shaped metallic element 60 which is adapted to bear against the contact point 54 of the lamp 15. The element 60 is mounted in and projects through the disk 20 which is of insulating material and 40 which may be provided with a pair of radially projecting ears 64 adapted to ride in the slots 48 and 50. The rear end of the spring 22 extends through a central aperture 68 in the disk 21 and bears against a metal piece 10, preferably of sheet sleet itselu ullginIg Iuroi UJe plane ereL I .. 5 metal piece 70 may be secured to the disk 21 by any suitable means such as a pair of tabs 76 bent to engage the opposite face of the disk 21, the tabs being disposed in peripheral notches 78 in the disk so as to avoid contact with the sleeve 10 13 in which the disk 21 is loosely mounted. The disk 21 is provided with radial ears. 80 engaging the slots 48 and 50 of the sleeve 13 so that the disk rotates with the sleeve when the latter is turned. The insulating plate 25, which is secured at the rear end of the housing member 12, is provided with a pair of conductors 84, 86, these conductors having portions extending through the plate 25 and ending flush with the front face thereof. As indicated in Figure 4, the conductors 84 and 86 are so arranged as to be engageable simultaneously by the elements 72 and 74 when the disk 21 is turned to a suitable angular position. Thus rotation of the sleeve 13 and disk 21 is adapted to move the conducting elements 72 and 74 into and out of simultaneous contact with the conductors 84 and 86. Since the elements 72 and 74 are always electrically connected by the metal piece 70 of which they are a part, such simultaneous contact with the conductors 84 and 86 serves to connect these conductors electrically so as to close the switch. Since the spring 22 engages the metal piece 70 and the element 60, and, since the latter presses against the contact point 54 of the lamp 15, a conducting path is thus provided for current to light the lamp 15 when the switch is closed, the circuit being completed through the pins 52 which are grounded through the socket 14, the sleeve 13 and the housing 12. For operation of the switch, the hollow shaft portion II of the knob 10 is provided with a slot 90 which interlocks with an ear 92 struck out from the sleeve 13. The hollow shaft II is adapted to fit snugly over the forward portion 38 of the split sleeve 13 and to be in telescoped frictional engagement therewith. It is evident that rotation of the knob 10 will result in rotation of the sleeve 13 and of the disk 21. This moves the conducting elements 72 and 74 into and out of simultaneous engagement with the conductors 84 and 86, thus closing or opening the switch as desired, the switch being held in its closed or open position by the engagement of the ears 40 and 41 in certain of the notches 34 in the sleeve 12 under the pressure of the spring 22. When the switch is closed and the elements 72 and 74 are connected to a source of potential, a path for current to the lanip 15 is provided through the spring 22 and the element 60, the shell of the lamp base being grounded, so that, when the switch is in use, the lamp is lighted when the switch is "on".
It is evident that various modifications and changes may be made in the specific embodiment of the invention herein shown and described without departing from the spirit or scope thereof as defined in the following claims.
I claim:-1. An electric switch comprising a cylindrical housing member having a portion cut away from the rear end thereof to form an arcuate edge in a transverse plane between the ends of the housing, a split sleeve loosely fitted in said housing, said sleeve having an ear projecting radially from its rear end and riding on said arcuate edge whereby rotation of said sleeve relative to said housing member is limited, a plate of insulating material closing the rear end of said housing member, a pair of conductors extending through said plate and ending flush with the forward face thereof, a disk fitted in the rear end of said sleeve and rotatable therewith, a pair of electrically connected conducting elements projecting rearwardly from the face of said disk and movable by rotation of said disk into and out of contact with the forward ends of said conductors, a knob having a shaft projecting into the forward end of said housing and frictionally telescoping said sleeve, means locking said knob and sleeve against relative rotation, and means resiliently pressing said disk against said plate. 2. An electric switch comprising a cylindrical housing member having a portion cut away from the rear end thereof to form an arcuate edge with a shallow notch at each end of said edge, a split sleeve loosely fitted in said housing, said sleeve having a radially projecting ear at the rear end thereof adapted to ride on said arcuate edge from one said notch to the other as said sleeve is rotated in said housing member, a plate of insulating material closing the rear end of said housing member, a pair of conductors extending through said plate so that their forward ends are flush with the forward face of the plate, a disk fitted in the rear end of said sleeve to rotate therewith, said disk having a pair of electrically connected conducting elements projecting from its rear face to bear against the front face of said plate and movable into and out of simultaneous contact with said conductors when the ear on said sleeve moves from one said notch to the other, a knob removably attached to said sleeve for rotation therewith, and means resiliently pressing said sleeve forward and said disk rearward whereby said ear is pressed against said arcuate edge. 3. An electric switch comprising a cylindrical housing having a portion cut away from the rear end thereof to form an arcuate edge, a split sleeve having an ear projecting radially from its rear end and riding on said arcuate edge to limit the angle of relative rotation between said sleeve and said housing member, a tubular lamp socket within said sleeve having bayonet. slots for engagement with pins on a lamp base, means holding said socket against rotation and forward movement relative to said sleeve, a plate of insulating material closing the rear end of said housing member, a pair of conductors extending through said plate and ending flush with the forward face thereof, a pair of disks of insulating material loosely carried in said sleeve and rotatable therewith, one said disk having a pair of electrically connected conducting elements projecting from the rear face thereof and movable into and out of simultaneous contact with the flush ends of said conductors by rotation of said sleeve, the other disk having a central conducting element adapted to bear against the central contact point of a lamp mounted in said socket, a compressed spring between said disks electrically connecting all said conducting elements, and an operating knob of translucent material operatively engaging said sleeve for rotation therewith. 70 4. An electric switch comprising a cylindrical housing member, a plate of insulating materiaý secured across the rear end of said housing member, a pair of conductors extending through said plate and ending flush with the forward face of said plate, an operating knob having a shaft portion projecting into the forward end of said housing, a tubular sleeve member in said housing in telescoped relation with said shaft portion and keyed thereto for rotation therewith, said sleeve having a pair of notches in its rear end portion, an axially movable member disposed in the rear end of said sleeve and provided with a pair of radial ears engaging in said notches for rotation of said axially movable member with said sleeve, said axially movable member having a pair of electrically connected conducting elements projecting rearwardly for sliding engagement with the forward face of said plate and movable by rotation of said sleeve into and out of simultaneous contact with the flush ends of said conductors, and means within said housing simultaneously pressing said conducting elements rearwardly against said plate.