US2751452A - Adjustable speed responsive switch - Google Patents

Description

June 19, 1956 J. K. GAYLORD ET AL 2,751,452

ADJUSTABLE SPEED RESPONSIVE SWITCH Filed Dec. l5, 1955 @fmes @725 `a lord f77/HJ R. 7@277/ 252 en forst' .imperante srnnn nnsronsrvn swrrcn lames K. Gaylord and rving R. Green, Chicago, lli., assignors to Gayiord Products, incorporated, Chicago, lil., a corporation of Delaware Appiication December 15, 1953, Serial No. 398,313

2 Claims. (Cl. 2Min-80) This invention relates to improvements in a speed responsive electric switch and refers particularly to a speed responsive switch which will break an electrical circuit at a predetermined speed of a rotating body and which will complete the same or a different electrical circuit at a predetermined speed of the body higher than said firstmentioned speed, the device being characterized in that the circuit-breaking and ycircuit-making speeds may be independently adjustably predetermined.

One of the important features of the present invention resides in the provision of a speed responsive electric switch which operates in response to the speed of a rotating body in the manner contemplated in the copending application for Letters Patent Serial No. 308,085, tiled September 5, 1952, in the name of Lewis E. Thatcher, now Patent No. 2,678,977, issued May 18, 1954, the present invention being charcterized in that the rotating speed at which an electric circuit is broken and the rotating speed at which the same or a different electric circuit is made is adjustable.

The objects and advantages of the present invention will be apparent from the accompanying drawing and following detailed description.

In the drawing,

Fig. l is a sectional elevational view of the improved switch.

Fig. 2 is a transverse sectional veiw taken on line 2 2 of Fig. l.

Fig. 3 is a transverse sectional view taken on line 3 3 of Fig. l.

Fig. 4 is an enlarged perspective view of one of the circuit-bridging vanes.

Although the present invention may be employed in many environments and to control substantially any type of electric circuit, for purposes of illustration, the invention will be shown and described as being responsive to the rotating speed of the usual automobile speedometer cable. However, it is to be understood that the invention is not to be limited to this environment.

Referring in detail to the drawing, 1 indicates generally the speed responsive switch comprising the present invention. The device 1 comprises a cup-shaped housing 2 which is substantially closed at its bottom and is open at its top. The housing 1 is preferably constructed of a synthetic plastic, hard rubber or the like, but may, if desired, be constructed of metal. A mounting plate 3 may be formed integral with the cup-shaped housing 2 and may be provided with holes 4 whereby the housing 2 may be mounted upon a suitable support, preferably a substantially vertical wall. The lower portion of the housing 2 may carry an integral split sleeve 5 which may terminate laterally in a pair of spaced lugs 6 through which a bolt 7 is adapted to pass.

For purposes of illustration the present invention is shown in conjunction with a speedometer cable 8. The switch comprising the present invention will function to control one or two electric circuits in response to the rotary speed of the speedometer cable 8. As will be States Patent hereinafter more fully described, the speedometer cable 8 passes through the central portion of the housing 2. To securely fasten the housing relative to the speedometer cable the sheath 9 of the speedometer cable is cut away for a predetermined portion of the length of the cable and one end of the sheath is inserted in the split sleeve 5 whereby, by the proper manipulation of the bolt 7 the lugs 6 may function to securely clamp the end of the sheath 9.

The housing 2 is provided with a cover 10 which may be secured to the upper portion of the housing 2 by means of a fastening ring 11. The speedometer cable 8 passes through an opening in the cover 10 and the cover at its upper portion carries a split sleeve 12 similar to the sleeve 5 hereinbefore described, the sleeve 12 having spaced lugs 13 which may be secured together by means of bolt 14. ln this fashion, the cover 10 may be securely fastened to the spaced end of the speedometer sheath 9. The cover 10 is preferably constructed of the same material comprising the housing 2.

An annular trough 15 is adapted to be positioned in the housing 2, said trough being substantially U-shaped in transverse section and being provided with a central opening 16 through which the speedometer cable S passes. A metal quill or collar 17 embraces the speedometer cable 8 within the housing 2 and is rigidly secured to the speedometer cable. The quill 17 carries oppositely extending arms 18 which are positioned transversely across the mouth of the annular trough 15. The quill 17 is rotatably positioned in the opening 16 in the trough and hence when the speedometer cable 8 rotates the quill 17 also rotates and arms 18 swing in a rotating fashion across the mouth of the trough 15.

Each of the arms 18 have downwardly extending portions 19 and 20 which are spaced from each other. A hinge pin 21 is carried between each pair of spaced lugs 19 and 20 and a vane 22 is adapted to be carried by each of the hinge pins 21. The vane 22, shown in detail in Fig. 4, comprises a plate having a cut away portion 23. Adjacent the cut away portion 23 the plate is bent upon itself to form a sleeve 24. The vane 22 is mounted upon the arms 18 by the passage of the pins 21 through the sleeves 24. Thus, the vanes 22 are swingable upon the opposite arms 18.

The sheath 9 of the speedometer cable is grounded as at 25 in Fig. l and hence the speedometer cable 8 being constructed of metal, is also grounded. The quill 17' and arms 18 are also constructed of an electrically conducted material and vanes 22 are also electrically con ductve. As will be hereinafter more fully described, the elements hereinabove enumerated comprise a portion of the electric circuit or circuits which are to be controlled by the switch.

A disc 26 constructed of an insulating material is positioned over the mouth of the trough 15 and is preferably cemented at its periphery to the outer, upper, defining wall of the trough. The plate 26 is provided with a central aperture through which the quill 17 extends, the quill being rotatable with respect to said plate. Circumferentially spaced screws Z7 are threadedly positioned in plate 26 and carry at their lower ends an adjustable contact ring 28, screws being secured to the ring 28 by swivel sockets 29 whereby the screws are rotatable relative to the ring 28 but function to raise and lower the ring 28 when they are manipulated. The ring 28 may be connected by means of conductor 30 to a suitable electric circuit.

At the lower portion of the annular trough 15 a metallic plate 31 is positioned, said plate being secured by means of swivel sockets 32 to screws 33 which are threadedly positioned through the bottom of the housing 2. The arrangement is such that when screws 33 are rotated the plate 31 may be raised or lowered within the trough 15. The plate 31 is electrically connected to a suitable circuit by means of conductor 34.

As is described in the application for patent tiled by Lewis E. Thatcher, hereinbefore identified, a bath or pool of non-conductive liquid 35 is adapted to be positioned in the annular trough 15 above plate 31. The arrangement is such that when the speedometer cable 8 is rotated whereby the vanes 22 are rotated within the trough 15, the lower portion of said vanes are raised from plate 31 by means of the frictional contact of the vanes with the liquid 35.

In the use of the present device, the plate 31 is connected by means of conductor 34 to a suitable source of voltage and to an electrically actuated device (not shown) which is to be controlled by the switch. The plate 31 is raised within the trough 15 until the plate makes contact with the lower edges of the vanes 22. Thus a completed electrical circuit is formed to the ground 25. When the speedometer cable 8 rotates the vanes 22 will be deflected by their frictional contact with the liquid 35 and hence at a predetermined speed said vanes will break contact with plate 31. Thus, the electrical circuit of which the switch comprises a part, is broken. As a feature of the present invention, the plate 31 may be raised or lowered within the trough 15. The lowermost active position of plate 31 is such that, if the device is maintained with the speedometer cable passing substantially vertically therethrough, vanes 22 will be substantially vertical with the edges just touching the plate 3l. It can readily be seen that very slight rotation of the speedometer cable will thus cause the vanes to break contact with the plate 31. If desired, however, the plate 31 may be raised within the trough 15 whereby the vanes 22 will be inclined with respect to the plate 3l. Of course, the vanes 22 will be in contact with the plate 31 and the associated circuit will be completed. Slight rotation, however, of the speedometer cable 8 will not cause the vanes 22 to break Contact with the plate. Contact between the vanes 22 and plate 31 will only be broken at a higher speed of the speedometer cable 8. Accordingly, by the proper manipulation of screws 33 and the desired elevation or depression of plate 31, the circuit can be caused to bebroken at higher or lower speeds of the speedometer cable 8.

As another feature of the present invention, when the vanes 22 are in substantially vertical position within the trough l5, the circuit connected to conductor 30 will be open. As the speed of the speedometer cable 8 increases, however, a speed will eventually be reached at which the vanes 22 will be canted by their contact with the liquid 35 to a degree whereby the cut away shoulders 23 of the vanes will make contact with the ring 28. When the vanes thus contact the ring 28 the electrical circuit including conductor 30 and ground 28 will be completed. Thus, the ring 28 functions as a high speed operated switch. It can readily be seen that by the proper manipulation of screws 27 and by desirably raising or lowering the ring 28, the rotating speed of the speedometer cable 8 at which the circuit comprising conductor 30 is completed, may be adjusted relative to various speeds of the speedometer cable.

It can readily be seen that the vanes 22 and plate 31 may function to control the circuit including conductor 34, that is, to break said circuit at a predetermined minimum speed. lt can also be seen that the ring 28 and vanes 22 may function to complete the circuit in which the conductor 30 is a part. The circuit which includes the conductor 34 may be a separate circuit from that which includes the conductor 3l) or both of said conductors may be included in the same circuit. If separate circuits are employed, the vanes 22 and plate 3l may function to open one circuit at a predetermined speed and the ring 28 and vanes 22 may function to close a separate circuit at a predetermined speed. lf the conl? ductors 30 and 34 are part of the same circuit, the vanes 22 and plate 31 may function to open said circuit at a predetermined speed and the circuit will remain open as the speedometer cable increases its speed until the ring 28 and vanes 22 close said circuit.

It can readily be appreciated that the switch may be used to control substantially any type of electrically actuated apparatus and the switch 1 may be employed in many other environments than the one hereinbefore described. Of course, in addition to the adjustability contributed by the movable plate 31 and the movable ring 28, the response of the switch may be changed by changing the weight of the vanes 22 or by changing the viscosity of the liquid 35. Of course, as heavier vanes 22 are employed, the speed at which said vanes break contact with the plate 3l will be increased and the speed at which the vanes 22 make contact with ring7 2S will also be increased. The speed referred to above has reference to the speed of rotation of the speedometer cable 8. If the viscosity of the liquid 35 is increased, the speed of the speedometer cable 8 at which the vanes break contact with plate 31 will be decreased and the speed of the cable 8 at which the vanes make contact with ring 28 will be decreased. Thus, the switch comprising the present invention may be tailored to meet the requirements of a large range of speeds.

We claim as our invention:

l. An electric switch responsive to the speed of rotation of a rotating body comprising a closed housing, a rotatable element in said housing, means for connecting said rotating element and said rotating body to rotate said element in timed relationship with the rotation of said body, said rotatable element comprising a vane constructed of an electrical conductive material and substantially horizontally disposed pivot means for pivotally snspending said vane, a pool of non-conductive liquid carried in said housing in which the free end of said vane dips, an annular relatively flat conductive plate positioned in said housing in said pool of liquid with its plane disposed substantially horizontally and with which said vane makes contact when said rotatable element is stationary, said vane breaking contact with said plate by the trictional detlective force of said liquid upon said vane when said rotating element rotates at a predetermined speed, means for adjustably raising and lowering said plate transverse to its plane to change the angle of contact of said vane and plate when said element is stationary, an electrically conductive contact member positioned in said housing and disposed in the path of travel of said vane when said vane is deflected a predetermined degree at a predetermined speed of said element, means for adjustably raising and lowering said contact member in said housing to cause contact of said contact member and said vane at different speeds of said element, means for connecting said plate and vane to an electrical circuit, and means for connecting said contact member and said vane to an electrical circuit.

2. An electric switch responsive to the speed of rotation of a rotating body comprising a closed housing, a rotatable element in said housing, means for connecting said rotating element and said rotating body to rotate said element in timed relationship with the rotation of said body, said rotatable element comprising a vane constructed of an electrical conductive material and substantially horizontally disposed pivot means for pivotally suspending said vane, a pool of non-conductive liquid carried in said housing in which the free end of said vane dips, an annular relatively flat conductive plate positioned in said housing in said pool of liquid with its plane disposed substantially horizontally and with which the lower edge of said vane makes contact when said rotatable element is stationary, said vane breaking contact with said plate by the frictional deflective force of said liquid upon said vane when said rotating element rotates at a predetermined speed, means for adjustably raising and lower- 6 ing said plate to change the angle of contact of the lower said plate and vane to an electrical circuit, and means for edges of said vane and the plate when said element is connecting said ring and said vane to an electrical circuit. stationary, an electrically conductive ring positioned in said housing and disposed in the path of travel of an References Cited in the 51e 0f this Patent upper edge portion of said vane when said vane is detlected a predetermined degree at a predetermined speed UNITED STATES PATENTS of said element, means for adjustably raising and lowering grllzgt ld/1;; 131 said ring m said housmg to cause contact of sald ring at 2,428,589 Aandewiel Oct. 7I 1947 vdifferent speeds of said element, means for connecting

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