US2766347A - Adjustable rotary speed responsive switch - Google Patents

Description

Och 1956 J. K. GAYLORD ETAL 2,766,347

ADJUSTABLE ROTARY SPEED RESPONSIVE SWITCH Filed April 1, 1954 United States Patent ADJUSTABLE ROTARY SPEED RESPONSIVE SWITCH James K. Gaylord and Paul T. Hahn, Chicago, 111., assignors to Gaylord Products, Incorporated, Chicago, 11]., a corporation of Delaware Application April 1, 1954, Serial No. 420,324

4 Claims. (Cl. 200-80) This invention relates to improvements in a rotary speed responsive switch and refers particularly to an electric switch which will make and break an electric circuit in response to difierent rotary speeds of a rotating body.

One of the important features of the present invention resides in the provision of an electric switch which can be made to close an electric circuit in response to a predetermined rotary speed of a body and to open the switch at a different predetermined speed of rotation, the rotation proceeding in the same direction, or the device may be made responsive to close a circuit in response to a predetermined rotational speed in one direction and opens the circuit in response to a predetermined rotational speed in the opposite direction.

Another important feature of the invention resides in a switch which is responsive to the rotational speed of a body, as heretofore described, wherein the responsive rotational speed of closing and opening of the circuit, with rotation proceeding in either direction, can be quickly and conveniently changed over a wide range of rotational speeds.

A further'important feature of the invention resides in a switch, of the character described, which opens and closes with the rapidity necessary to avoid excess arcing at the switch points.

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

In the drawing,

Fig. 1 is a sectional View taken through an embodiment of the present invention.

Fig. 2 is a transverse sectional view taken on line 2-2 of Fig. 1.

Fig. 3 is a transverse sectional view taken on line 3-3 of Fig. 1, showing the switch in open position.

Fig. 4 is a sectional view similar to that shown in Fig. 3, illustrating the switch in closed position.

Although the present invention may be used in substantially any environment to control substantially any type electrical circuit in response to the rotational speed of any rotating body, for purposes of illustration the invention will be described in conjunction with an automobile tocontrol an electric circuit associated with the automobile, the control being exercised in response to the movement of the automobile. To conveniently control the desired electrical circuit in response to the movement of the automobile the speedometer cable, which moves in proportion to the movement of the automobile, will be employed as the controlling rotating body.

Referring in detail to the drawing, 1 indicates generally an embodiment of the present invention. The dev ce 1 comprises a cup-shaped container 2 WhICh IS open at its upper end and which may be closed by a suitableclosure 3. The container 2 is preferably circular in section and has a circular outer wall 4 and a bottom 5. A tubular extension 6, preferably formed integral with the container bottom, extends upwardly from the bottom where- 2,766,347 Patented Oct. 9, 1956 by an annular compartment 7 is provided within the container. In utilizing the device, an electrically non-conductive liquid 8 is carried in the container.

The container 2 is preferably constructed of an electrical insulating material such as plastic, fiber, hard rubber or the like. The closure 3 comprises a circular disc portion 9 which, when the device is assembled, rests upon the upper edge of the annular wall 4 and may be sealed thereto as shown at 10 in Fig. l.

A boss 11 extends downwardly from the bottom 5 and is preferably formed integral with said bottom, said boss being provided with a relatively enlarged bore 12 which is adapted to receive an end portion 13 of a speedometer cable sheath, the speedometer cable sheath embracing a conventional speedometer cable 14. The disc portion 9 of the closure 3 also carries an upwardly extending boss 15 similar to the boss 11, boss 15 being preferably integral with the disc 9. The boss 15 is provided with a bore 16 for the reception of a spaced end portion of the speedometer cable sheath, said end portion being designated by the reference numeral 17.

Both the boss 11 and boss 15 are provided with relatively restricted bores 18 and 19 respectively through which the cable 14 passes, said cable extending through the tubular extension 6 within the container 2.

A sleeve 20 is rotatably positioned in the hollow bore of the extension 6, said sleeve circumscribing the speedometer cable 14 and being spaced therefrom. A resilient friction gripping member 21 is positioned between the speedometer cable 14 and the upper end portion of the sleeve 20 and frictionally connects the speedometer cable to sleeve 20 whereby rotation of the speedometer cable causes sleeve 20 to rotate within the hollow bore of the projection 6. A spider 22 embraces the upper end portion of the sleeve 20 and carries a cap 23 which is rigidly mounted upon the sleeve 20. The spider 22 carries downwardly and outwardly extending arms 24 which are secured adjacent their end portions to a hollow semitoroidal driving rotor 25. The arrangement is such that when the speedometer cable 14 rotates the driving rotor 25 will be rotated. By virtue of the shape of the arms 24 the rotation of the driving rotor 25 will take place within the liquid 8 carried within the container 2.

A hollow semi-toroidal driven rotor 26 is positioned beneath the driving rotor 25, said driven rotor 26 comprising a hub 27 which is rotatably journalled upon the lower portion of the tubular extension 6. The driven rotor 26, being beneath the driving rotor 25 is, of course, also immersed within the body of liquid 8.

The rotors 25 and 26 are of the same general construction which is employed in hydraulic torque converters for power transmission purposes particularly in automotive vehicles. Each of the rotors 25, as has been hereinbefore described, is of hollow construction and the semi-toroidal spaces defined by the walls of the rotors are divided by a plurality of circumferentially spaced partitions 28 and 29, being the partitions of the rotor 25 and 26 respectively. Thus, the interiors of the rotors 25 and 26 are divided into a plurality of radial compartments, the compartments of the respective rotors facing each other.

The arrangement is such that when the driving rotor 25 is rotated by the speedometer cable 14 a torque will be exerted upon the driven rotor 26. As has been hereinbefore described the driven rotor 26 is freely rotatable upon the lower portion of the tubular extension 6. However, as will be hereinafter more fully described, the torque exerted upon the driven rotor 26 is resisted resiliently and consequently the rotational movement of the driven rotor 26 is relatively restricted.

A resilient frame 30 is positioned within the container 2 adjacent the bottom portion thereof. The frame 30 comprises a side 31 which is rigidly secured to the Wall 4 of the container 2 by means of rivets or the like 32. The frame 3% also comprises a side 33 which is integrally joined to side 31, the side 33 extending at an angle to the side 31. At the opposite end of the side 33 a side 34 is formed, said side being integrally connected to side 33. An anchorage portion 35 also comprises a portion of frame 30, said anchorage portion extending from the side 31 and being formed integral therewith. The frame 31) is preferably formed of spring steel and the various sides, hereinbefore described, may be formed by appropriately bending the steel strip from which the frame is formed.

Intermediate the length of the side 34 of frame 30 a U-shaped loop 36 is formed. The driven rotor 26, adjacent its outer periphery, carries a downwardly extending lug 37 which extends into the loop 36. Thus, the torque exerted upon the driven rotor 26 by the driving rotor 25 is resisted by the engagement of the lug 37 in loop 36, that is, said torque is resiliently resisted by the frame 30.

The side Wall 4 of the container 2 is provided with an internally threaded aperture 38 which is adapted to receive a threaded plug 39. One end of the plug 39 is relatively restricted in diameter to form "a switch contact point 40 which extends inwardly into the compartment 7. The anchorage member 35 of the frame 30, adjacent its end, extends at an angle to itself to form an anchorage lug 41. The lug 41 is provided with an aperture or slot in which an end portion 42 of a movable contact arm 43 is pivotally positioned. The movable contact arm carries a switch contact point 44 which is positioned adjacent the contact point 40, the contact point 44 being movable toward and away from the contact point 40 to make and break an electrical circuit. The movable contact supporting arm 43 is bent at an angle adjacent its end to form a toggle supporting lug 45. The lug 45 is provided with an aperture for the reception of an end portion 46 of a toggle link 47, the opposite end portion 48 of said link engaging in an aperture provided in the end portion of side 34 of frame 30. As will be hereinafter more fully described the assembly comprising the movable contact supporting arm 43 and the toggle link 47 comprises a toggle mechanism whereby the switch points 40 and 44 may be brought together or separated rapidly, that is, the contact 44 snaps into electrical contact with the contact 40 when the switch is closed and snaps away from the contact 40 when the switch is open. Thus the electrical circuit which may be associated with the contacts 40 and 44 may be made or broken rapidly inhibiting arcing at the contact points.

The engagement of the toggle link 47 with the side 34 and lug 45 is such that the link is pivotally associated with each of said members and also has a degree of freedom along its length, that is, the end portions 46 and 48 are of less width than the remaining body portion of the link and extend loosely into the apertures provided in lug 45 and side 34, respectively. The same arrangement exists between the end 42 of the arm 43 and lu 42.

ln operation, when the driving rotor 25 exerts a torque upon the driven rotor 26, a thrust is exerted upon the side 34 of the resilient frame 30 tending to move sa d side along substantially the direction of its length. This thrust is resiliently resisted by the frame 30 and results in movement of the toggle linkag comprising arm 43 and link 47. The resilient resistance of frame 30 may be changed by adjusting screw 49 which is threadedly positioned in an aperture 50 provided in wall 4. The screw 49 has a contact end 51 which may be brought to bear upon side 33 of frame 30 whereby the resilience of said side may be varied by the manipulation of the screw 49.

For example, for a predetermined setting of screw 49, the frame may be disposed, as shown in Fig. 3, that is, the switch points 40 and 44 are separated. When the points 40 and 44 are separated, the link 47 will be in an inclined position between lug 45 and side 34. In the normal setting of the frame 30 and toggle linkag comprising arm 43 and link 47, side 34 will exert a compressive stress lengthwise of link 47. This stress will tend to rock arm 43 about its pivotal connection with lug 41, and when the link 47 is on the side shown in Fig. 3 of its center position, this rocking action of arm 43 will take place in a clockwise direction. To prevent excessive rocking movement of arm 43 in this direction, a stop lug 52 positioned upon the base of the extension 6 contacts an intermediate portion of arm 43 thereby limiting such clockwise movement of the toggle linkage.

In the position of the parts, hereinbefore described, it is assumed that the cable 14 is stationary and, hence, no torque is exerted upon the rotor 26. Accordingly, the contacts 40 and 44 are held apart by the normal tension of the frame and toggle linkage, the latter being restrained by the stop 52.

If the cable 14 is now rotated in the direction indicated by the arrow 53 in Fig. 4, a torque will be exerted upon the driven rotor 26 and a thrust will be exerted upon side 34 in the direction indicated by the arrow 54 in Fig. 4. This thrust will be resisted by frame 30, principally by side 33 thereof which will tend to flex. Hence, side 34 moving in the direction of arrow 54 moves the end 48 of the link 47 in the same general direction. By virtue of the stop 52 the opposite end 46 of link 47 will remain stationary and thus link 47 will pivot about lug 45 in a clockwise direction, as viewed in Fig. 4.

The torque exerted upon the driven rotor 26 is proportional to the rate of rotation of the driving rotor 25. Hence, if the driving rotor 25 rotates at a predetermined speed, sufficiently great to cause side 34 to move link 47 to its center position, that is, a horizontal position as viewed in Figs. 3 and 4, the link 47 will be in an unstable position and hence a slight increase in torque will cause the link 47 to move arm 43 to the position shown in Fig. 4 wherein contacts 40 and 44 are together. When the link 47 is in its center position the bending stress upon the side 34 is at its maximum, that is, the compression exerted upon the link 47 is at its maximum. Hence, when the link 47 passes said center position due to the thrust exerted upon the side 34, the arm 43 will move rapidly to the position shown in Fig. 4. This rapid movement is occasioned substantially by the flexing of the side 34.

Hence, at a predetermined speed of rotation of the cable '14 an electric circuit which may include contacts 40 and 44 which may be in normally spaced position, will be closed.

As has been hereinbefore described, the movement of side 34 in the direction of the arrow '54 is dependent upon the thrust exerted upon the driven rotor 26. This movement of side 34 is also dependent upon the resistance to such movement offered by side 33. Hence, for a predetermined speed of rotation of cable '14 the side 34 will be moved so as to cause the contacts 40 and 44 to close. By the proper manipulation of the adjusting screw 49 the side '33 can be made to offer a greater or lesser resistance to movement of the side 34. Hence, by moving screw 49 inwardly with respect to the wall 4 the side 33 can, in effect, be stiffened, that is, it can be made to offer greater resilient resistance to the thrust exerted by the driven rotor 26. Hence, the contacts =40 and '44 will not close until a greater speed of rotation of the cable 14 occurs. The screw 49 may be referred to as a high speed adjustment, that is, its manipulation will determine the maximum speed of cable 14 at which the contacts will close.

*If the cable 14 now slows down, the resistance of the frame 30, principally the side 33, will tend to move the end 48 of the link 47 downwardly as viewed in Figs. 3 and 4. In other words, the side 34 will move in a direction contrary to arrow '54. In view of the fact that contact 44 abuts contact 40' the opposite end '46 of link 47 will remain stationary and hence link 47 will pivot in a counterclockwise direction about lug 45 as viewed in Fig. 4. if the cable 14 slows down to a predetermined degree of rotation the link 47 will eventually move to its unstable center position. Thereafter, a slight decrease in speed of cable 14 will cause arm 43 to rock in a clockwise direction about lug 41 thereby separating contact 4-4 from contact 40 and opening the electrical circuit which includes said contacts.

The time at which contact 44 separates from contact 40 depends upon the adjustment of screw 39. For instance, if it is desired to have contacts 44 and 40 separate when the cable 1-4 has slowed down a relatively small amount from its maximum speed, the screw '39 will be moved inwardly relative to the wall 4. 'If on the other hand, it is desired that the contacts separate only after a relatively large decrease of speed from maximum, the adjustment of screw 39 will be such as to move said screw outwardly relative to the wall 4. The screw 39 may be referred to as the low speed adjusting screw since its position determines at what predetermined speed of cable 14 the contacts will separate after the cable slows down from its maximum speed. Accordingly, it can readily be seen that by the proper adjustment of screws 49 and G9 the electric circuit can be closed and opened at substantially any desired range of differential speeds. In other words, the screw 49 may be so adjusted as to cause the circuit to be completed only when a relatively high speed is reached and the screw 39 may be so adjusted as to cause the circuit to be broken when the speed drops off a relatively small degree or by the proper manipulation of screw 39 the circuit may be caused to be broken only if the speed has decreased a relatively great amout from that at which the circuit was made.

In order to prevent an excessively high torque being applied to the driven rotor 26, after the contacts 40 and 44 close, bleed openings 55 may be provided in the wall of the driving rotor 25. Hence, when suflicient torque has been exerted upon the driven rotor 26 to cause the contacts to close, any increase in the pressure of the fluid coupling between the driving and driven rotors will be relieved 'by passage of fluid outwardly through the openings 55. An opening 55 may be provided into each of the compartments defined by the radial walls 28.

In order to conveniently connect the contacts 40 and 44 to an external circuit a jack 56 may be secured to the outer surface of the wall 4, said jack being carried by a bus bar 57 which may be connected through the wall 4 by means of rivets 58 to a jumper bar 59 which in turn may be in electrical connection with contact 40. Similarly a jack 60 carried by bus bar 61 may connect through rivet 32 to the frame 30 which carries the contact 44, the contact being grounded upon said frame. Thus, the switch may be conveniently connected to a desired electrical circuit (not shown).

In the example of the operation of the device '1, hereinbefore set forth, the same direction of rotation of the cable 14 was assumed. In view of the fact that the toggle linkage comprising arm 43 and link 47 is stable in either the circuit-open or circuit-closed position it is possible to close the circuit at a predetermined speed .in one direction and open the circuit at a predetermined speed of the cable in the opposite direction.

By the provision of the high speed adjusting screw 49 and the low speed adjusting screw 39 the switch can be caused to open or close the electric circuit at any speeds throughout the full range of speed of the cable and the opening and closing speeds may be selected with a small differential or a large differential, as desired. For instance if top speed of cable 14 is 100 revolutions per minute, the switch may be so adjusted as to close the electric circuit at, for instance, 90 revolutions per minute and open the circuit when the cable slows down to 80 revolutions per minute, that is, with a differential of l 6 revolutions per minute. However, using the same differential, the closing speed may be selected at 50 revolutions Per minute. nd the opening speed at 40 revolutions per minute, or closing speed may be 15 and opening may be 5. In addition, the differential may be relatively great, for instance, the switch may be so adjusted as to close at revolutions per minute and open at 10 revolutions or the closing of the switch may be set at any speed within the positive range of speed of the cable and may open at any opposite rotational speed.

Of course, the examples set forth herein are merely for the purpose of illustrating the flexibility of operation of the device and are not intended as a limitation of the invention.

We claim as our invention:

"1. A rotary speed responsive electric switch which comprises in combination, a container for carrying an electrically non-conductive fluid, a fluid coupled driving rotor and driven rotor immersed in said fluid, means for rotating said driving rotor to exert a torque upon said driven rotor, a resilient frame of predetermined stiffness carried in said container, means connecting said driven rotor to said frame to flex said frame when torque is exerted upon said driven rotor, a toggle mechanism connected to said frame, said toggle mechanism having a movable arm, a switch contact point carried by said movable arm, a stationary juxtaposed companion switch contact point carried within said container whereby predetermined rotation speeds of said driving rotor causes said movable arm to close and open said contact points, means carried by said container for changing the stiffness of said resilient frame to change the movement of said arm relative to the rotary speed of said driving rotor, and means for changing the position of said stationary contact relative to the contact carried by said arm to change the responsive speed at which the contacts open.

2. A rotary speed responsive electric switch which comprises in combination, a container for carrying an electrically non-conductive fluid, a fluid coupled driving rotor and driven rotor immersed in said fluid, means for rotating said driving rotor to exert a torque upon said driven rotor, a resilient frame of predetermined stiffness carried in said container, means connecting said driven rotor to said frame to flex said frame when torque is exerted upon said driven rotor, a toggle mechanism connected to said frame, said toggle mechanism having a movable arm, a switch contact point carried by said movable arm, a stationary juxtaposed companion switch contact point carried within said container whereby predetermined rotation speeds of said driving rotor causes said movable arm to close and open said contact points, and means carried by said container for changing the stiffness of said resilient frame to change the movement of said arm relative to the rotary speed of said driving rotor.

3. A rotary speed responsive electric switch which comprises in combination, a container for carrying an electrically non-conductive fluid, a fluid coupled driving rotor and driven rotor immersed in said fluid, means for rotating said driving rotor to exert a torque upon said driven rotor, a resilient frame of predetermined stiffness carried in said container, means connecting said driven rotor to said frame to flex said frame when torque is exerted upon said driven rotor, a toggle mechanism connected to said frame, said toggle mechanism having a movable arm, a switch contact point carried by said movable arm, a stationary juxtaposed companion switch contact point carried within said container whereby predetermined rotation speeds of said driving rotor causes said movable arm to close and open said contact points, and means for changing the stiffness of said frame to change the responsive speed at which the contacts close.

4. A rotary speed responsive electric switch which comprises in combination, a container for carrying an electrically non-conductive fluid, a fluid coupled driving rotor and driven rotor immersed in said fluid, means for 7 rotating said driving rotor to exert a torque upon said driven rotor, a resilient frame of predetermined stifiness carried in said container, means connecting said driven rotor to said frame to flex said frame when torque is exerted upon said driven rotor, a toggle mechanism connected to said frame, said toggle mechanism having a movable arm, a switch contact point carried by said movable arm, a stationary juxtaposed companion switch contact point carried within said container whereby predetermined rotation speeds of said driving rotor causes said movable arm to close and open said contact points, and means for changing the position of said stationary contact '8 relative to the contact carried by said arm to change the responsive speed at which the contacts open.

References Cited in the file of this patent UNITED STATES PATENTS 1,677,008 Townsend July 10, 1928 2,279,999 McKechnie Apr. 14, 1942 2,518,478 Kohl Aug. 15, 1950 2,558,223 Roger June 26, 1951 FOREIGN PATENTS 591,320 Great Britain Aug. 14, 1947

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