US3132268A

US3132268A - Motion e.m.f. generating transducer

Info

Publication number: US3132268A
Application number: US177597A
Authority: US
Inventors: Martin L Abel; Winters John
Original assignee: Force Controls Co
Current assignee: Force Controls Co
Priority date: 1962-03-05
Filing date: 1962-03-05
Publication date: 1964-05-05
Anticipated expiration: 1981-05-05
Also published as: GB1037313A

Description

May 5, 1954 M. l.. ABEL ETAL 3,132,263

MOTION E.M.F. GENERATING TRANSDUCER Filed March 5, 1962 2 Sheets-Sheet 1 i 0 5 H (3542 52 mm. 24M j.;

:ll.l I iw "uw f .50 4 sa/@awww 4 '5 45@ E' 96. f/// 24- m d 7 f minimun K25 wif #1:, ulm!! May 5, 1964 M. l.. ABEL ETAL 3,132,268

MOTION E.M.F. GENERATING TRANSDUCER Filed March 5, 1962 2 Sheets-Sheet 2 JZ f2 BY f7 W35@ United States Patent Oiiic/e Mich., assignors to Force Controls Company, Ferndale,

`Mich., a corporation of Michigan Filed Mar. 5, 1962, Ser. No. 177,597 10 Claims. (Cl. S10-15) This invention relates to a generator of the type adapted to sense a condition and to operate an electrical circuit in response thereto. More particularly, the invention Consists in the provision of a transducer and a triggering device associated therewith for energizing the transducer to operate an electrical control circuit in response to movement of the triggering device. The invention is characterized by the fact that the triggering device includes a movable contact button which will energize the transducer to generate a control signal of constant strength independent of the rate fat which the contact kbutton is moved. The point at which the triggering device energizes the transducer is also very accurately controlled so that the control signal is generated at a precise point within extremely small tolerances during each cycle of operation.

A principal object of the invention is to provide a new and improved generator for operating an electrical circuit.

Another object of the invention is to provide a generator comprising a transducer and a triggering device therefor which will energize the transducer to operate a solid state electrical circuit which performs a switching function with extreme accuracy.

Another object of the invention is to provide a triggering device for a transducer ywhich will energize the transducer to cause the latter to emita control signal of constant strength regardless of the rate of movement of the triggering device.'

y #Other and further objects of the invention will be apparent lfrom the following description and claims and may be understood byy reference to the accompanying drawings,

of which there are two sheets, whichby way'of illustration show preferred embodiments of the invention and what we now considerto be the best mode of applying the principles thereof. Other embodiments of the invention may ybe used without departing from the scopey of the presentinf vention as set forth inthe appended claims.

In the drawings: t n

FIG. l is an elevational Iview of a generator according to the present invention; v FIG. 2 is an enlarged sectional view taken on line 2 2 of FiG. l;

FIG. 3 is a view similar to FIG. 2 but showing the parts in a different operative position thereof;-y r

FIG. 4 is a sectional view taken on line 4 4 of FIG. 2;

TIG. 5 is a sectional view taken on line 5--5 of FIG. 2;

FIG. 6 is a sectional View illustrating a modified form of theinvention; and y p FlG. 7 is a circuit diagram illustrating one type of electrical circuit that may be used in conjunction with the transducer.

yThe presentinvention comprises a transducer 10 to-k gether with a triggering device 12, bothk contained Within a tubular housing 14. yReferring to FIG. 5, the transducer 10 comprises a pair offiron'cores or pole pieces 16 each having a coil ftd of `fine wire wrapped around one end thereof anda permanent magnet Ztifdisposed between the other ends of the cores 16. The coils 18 are wound onto insulating spools 22 which are fitted over the ends v a force transmitting member which will impart movement n Patented May 5, 1964 end thereof, with the lead wires 28 extending outwardly through a threaded opening 39 inthe housing 14.

iT he triggering device 12 comprises a contact button 32 which is exteriorly threaded to receive a lock nut 34 which engages a collar 36 which is also threaded onto the contact button l32 and is provided with a radial shoulder v38 engaging within a counterbore 40 in a sleeve 442 which is slidable within they bore 44 defining the inner wall of the housing 14; An exteriorly threaded washer 46 is threaded into the outer end of the bore 44 and is engaged by the sleeve 42 and the collar 36 to provide a stop limiting outward movement of such parts.`

An armature consisting of a soft iron disc y48 secured to a member 5@ is slidable within the central bore 52 of the sleeve 42. A shoulder 54 on the member'SO engages the inner end of the sleeve 42 and is held thereagainst by a spring 56 which is secured at one end to a pin 58 extending across a recess 6i) in the contact button 32 and `secured at its other end to a pin 62 disposed within a recess 64 in the member Sti. Obviously the disc 48 and the member 5@ may be made integral is desired. A spring do is confined ybetween one end of the sleeve 24 and a radial shoulder 68 on the sleeve 42 and urges the latter against the stop 46. y f y. y

'llhe contact button 32 is adapted to be yengaged by tothe Contact button in response to a change inthe condition being sensed. The parts are shown in FlG. 2 in the position they occupy when the force applied to the contact button 4has not ye'treached a value suiicient to depress n Athe contact button out of engagement with the stop 46.

y As the contact button 32 is depressed, the collar 38, sleeve of the cores 16. yThe permanent magnet 2t) is arranged n so that one of its poles faces one of the cores 16 while its opposite pole faces the other core 16. The transducer is encased within an insulating sleeve 24 which is inserted into the housing 14 to abut a shoulder `26 at thek inner 42 and armature 48 will be depressed as a unit against the force of the spring 66 to move ythe armature toward the exposed ends 70 of the cores 16 which extend a slight distance beyond the outer end '72 of the permanent magnet 20. When the armature 48 is spaced a certain predetermined distance rom the ends 7d of the cores 16, the magnetic `force will snap the armature 48 into engagement with thecores 16 against the force of spring 56, thereby moving thelines of flux over the coils 18 to induce an eleetromotive force which is supplied to a solid state electrical circuit indicated generally at 72 in FIG. 7, which is designed to perform a switching function to control any suitable electrical component such as a solenoid valve.

It will be seen that the strength of the control signal thatis generated in the transducery 1G is independent of the rate at which the contact button 32 is depressed because the armature 4S is free to move away from the sleeve 42 into engagement with the cores 16 when themagv45 approaches the cores-16, so that the rapid movement ofthe armature into engagement with the cores will occur at aprecisely controlled point or at a precise spacing of the armature from the cores. The parts are shown in FIG. 3 in the position they occupy after the armature has been pulled into engagement with the pole `pieces to generate a control vsignal. The rate at which 'the armature is snapped into yengagement with the poles will always be the same so that the strengthof the signal emitted willjbe constant `and independent of the rate at which the contact button is depressed. y n L v As the contact button is released, another control signal is generated which will also beof constant strength and independent of the rate of movement of the contact button.

the magnetic attraction thereof. The spring 56 is thereby stretched to exert an increasingly greater pull on the armature and, when the force exerted by the spring 56 exceeds the magnetic force, the. armature .will be pulled rapidly away from the cores 16 into engagement with the sleeve 42, thereby inducing another control signal in the coils 18.

The device may be made to accurately detect the position of an object whichengages the contact button by means of a micrometer adjustment which comprises an exteriorly threaded sleeve 80'which is axially slidably but nonrotatably mounted on the exterior of the housing 14 by means of a key 82. A collar 84 is xedly secured on theI housing 14 and is exteriorly threaded to mesh with a Calibrating sleeve 86 provided with an inwardly turned shoulder 88 engaging an outwardly extending shoulder 90 ,on the sleeve 80. The sleeve 80 is threaded into a threaded opening in a wall indicated at 92 to engage the contact button 32 with the load or a force transmitting member. The inwardly turned shoulder 88 on the calibrating sleeve 86 abuts against the wall 92 and also is engaged by the shoulder 90 on the sleeve 80. The sleeve 86 is provided with micrometer markings 94, and a Stationary part such as the wall 92 may be provided with a hairline so that the proper micrometer marking on the sleeve r86 which may be in pounds of torce can be aligned therewith. As the micrometer sleeve 86 is rotated, the housing 14 and the threaded collar 84 carried thereby and meshed with the micrometer sleeve will slide axially inwardly or outwardly through the sleeve 80 until the desiredreading is obtained. This adjustment of course varies the position of the contact button relative to the force transmitting member so that the device may be made to generate the control signal at any selected value. The micrometer sleeve may be locked by a lock nut 96.

The transducer may be used in conjunction with any suitable circuit such` as the circuit 72 shown in FIG. 7, which is illustrative only. The circuit shown in FIG. 7 may comprise the coils 18 which are wound so that the voltage developed in the coils as the armature is moved toward or away from the ends of the cores 16 will be of opposite polarity. The circuit further includes

transistors

100 and 102,

resistances

104, 106, 108 and 110, and an output terminal 112. The output terminals of the

transistors

100 and 102 are indicated at To and To' respectively. When power is supplied to the circuit, one of the transistors will shortly be conducting the current while the other is cut off, which constitutes one of the two stable states of the circuit. If, for example, the transistor 100 is conducting and the armature 48 is moved into engagement with the ends of the cores 16 in the manner described so as to produce a negative voltage exceeding the voltage developed across resistor 104 to be applied tothe base of transistor 102 and a positive voltage to be applied to the base of transistor 100, transistor 102 will then start conducting and reducing the amount that transistor 100 is conducting, which action once begun will continue rapidly until transistor 102 is conducting heavily while transistor 100 is cut oi. The output may then by taken from the collector of transistor 102. This repre- Vsents the other stable state of the circuit. When armature 48 is moved away from the cores 16,A another voltage is generated which will be negative on the base of transistor 100 and positive on the base of transistor 102, thereby to return the circuit to its other stable condition. The circuit is therefore a switching circuit and may be used to control any suitable electrically operated device such as a solenoid operated valve, an ignition circuit, or any other electrically actuated device. It will be apparent that other types of switching circuits may be employed and that the circuit illustrated forms no part of Ythe present invention. v

In the form of the invention illustrated in FIG. 6, the transducer may be of the same construction previously described and in this case it is contained within a threaded ,Y 4 insulating casing 120 which is threaded into an internal shoulder 122 formed in thewhousing 124. At its other end the housing 124 is threaded to receive a stop collar 126 having a recess 128 and a coaxial bore 130 within which the contact button 132 reciprocates. A spring 134 is conined between the contact button 132 and an annular disc 136 which engages an internal shoulder on the sleeve 138. A spring 140 conned between the internal shoulder 122 on the housing and the sleeve 138 urges the sleeve 138 and the disc 136 into the engagement with the collar 126.

. The armature 142 is secured to a rod 144 which extends slidably through the bottom wall 146 of the housing 138. Arspring 148 is confined between the wall 146 of the sleeve and a washer 150 on the rod 144 which engages a nut 152. threaded onto the outer end of the rod 144. When the contact button 132 is depressed by a force applied thereto, the spring 134 will be compressed and eventually will force the disc 136 and sleeve 138 `in Wardly against the spring 140 carrying the armature 142 toward the cores of the transducer. At a predetermined point, the magnetic force will rapidly move the armature 142 into engagement withthe cores, thereby compressing spring 148. When the force applied to the contact button is reduced, the spring 140 will move the sleeve 138 outwardly, further compressing spring 148 until the force of the latter spring exceeds the magnetic force holding the armature in position and at a predetermined point the armature will move rapidly out of engagement with the cores, thereby generating a second control signal. The device shown in FIG. 6 may also be provided with a micrometer adjustment if desired. The spring 134 allows some overtravel of the contact button 132 beyond that necessary to energize the transducer.

Since the rate at which the armature in either form of the invention moves toward the cores of the transducer is independent of the rate of movement of the Contact K button, the transducer will always generate a sufficiently strong signal of constant value to operate the control circuit. Thus with the present construction it is not possible-for the contact button to be moved so slowly as to fail to induce suicient current in the coils to energize the control circuit as is possible with prior art devices.

While we have illustrated and described preferred embodiments of our invention, it is understood that these are capable of modification, and we therefore do not wish to be limited to the precise details set forth but desire to avail ourselves of such changes and alterations as fall within the purview of the following claims.

We claim:

l. Ina device for sensing a condition and operating an electrical circuit in response thereto including a core having a coil wound thereon and a permanent magnet associated therewith, an armature movable into and out of engagement with said core, an actuating member adapted for movement in response to change in the condition being sensed, a motion transmitting connection between said armature and said actuating member so that said armature is movable with said actuating member toward said core until said armature is spaced a predetermined distance from said core whereupon the magnetic attraction causes said armature to snap into engagement with said'core therebyto induce a current in said coil independent of the rate of movement of said actuating member, and a spring connecting said actuating member and said armature for urging said armature into engagement with said actuating member but permitting movement of the latter away from said core while said armature remains in engagement therewith until said spring overcomes said magnetic attraction and pulls said armature away from said core and into engagement with said actuating member thereby to induce a second current in said coil independent of the rate of movement of said actuating member.

2. In combination with a transducer device including a core having a coil wound thereon and a permanent aisance magnet associated therewith, a triggering device for energizing said coil in response to a change in a condition being sensed, comprising an armature movable into and out of engagement with said core, an actuating member adapted for movement in response to change in the condition being sensed, a motion transmitting connection between said armature and said actuating member so that said armature is movable with said actuating member toward said core until said armature is spaced a predetermined distance irom said core whereupon the magnetic attraction causes said armature to snap into engagement with said core thereby to induce a current in said coil independent of the rate of movement of said actuating member, and a spring connecting said actuating member and said armature for urging said armature into engagement with said actuating member but permitting movement of the latter away from said core while said armature remains in engagement therewith until said spring pulls said armature away from Said core and into engagement with said actuating member thereby to induce a second current in said coil independent of the rate of movement of said actuating member.

3. ln a transducer for sensing a condition and operating an electrical circuit in response thereto including a core having a coil wound thereon and a permanent magnet associated therewith, an armature movable into and out of engagement with said core, an actuating member adapted for movement in response to change in the condition being sensed, a motion transmitting connection between said armature and said actuating member so that said armature is movable with said actuating member toward said core until said armature is spaced a predetermined distance from said core whereupon the magnetic attraction causes said armature to snap into engagement with said core thereby to induce a current in said coil independent of the rate of movement of said actuating member.

4. A transducer according to claim 3 including spring means urging said armature into engagement with said actuating member.

5. A transducer according to claim 4 including a spring urging said acuating member away from said core.

6. in a transducer for sensing a condition and operating an electrical circuit in response thereto, a pair of iron cores each having a coil wound thereon at one end thereof and a permanent ceramic magnet between the opposite ends of said cores, a housing, said transducer being mounted in one end of said housing, a triggering device mounted within the other end of said housing comprising an actuating member slidably mounted in said housing for movement toward and away from said transducer, a stop limiting movement of said actuating member away from said transducer, a spring urging said actuating member into engagement with said stop, an armature slidably mounted on said actuating member and opposed to the ends of said cores, said actuating member engaging said armature so that said armature is movable therewith toward said cores as a load is applied to said actuating member until said armature is spaced a predetermined distance from said cores whereupon the magnetic attraction causes said armature to snap into engagement with said cores thereby to induce a current in said coils the value of which is independent of the rate of movement of said actuating member', and a spring connecting said actuating member and said armature permitting movement of said actuating member away from said cores while said armature remains in engagement therewith as the load on said actuating member is decreased ti until said spring pulls said armature away from said cores and into engagement with said actuating member thereby to again induce a current in said coils the value of which is independent et the rate of movement of said actuating member.

7. lin an actuating device for a transducer including a core having a coil wound thereon and a permanent magnet associated therewith, an armature movable into and out of engagement with said core, an actuating member, a motion transmitting connection between said armature said actuating member so that said armature is movable with said actuating member toward said core until said armature is spaced a predetermined distance from said core whereupon the magnetic attraction causes said armature to snap into engagement with said core thereby to induce a current in said coil independent of the rate of movement of said actuating member.

8. ln an actuating device for a transducer including a core having a coil wound thereon and a permanent magnet associated therewith, an armature movable into and out of engagement with said core, an actuating member, a motion transmitting connection between said armature and said actuating member so that said armature is movable with said actuating member toward said core until said armature is spaced a predetermined distance from said core whereupon the magnetic attraction causes said armature to snap into engagement with said core thereby to induce a current in said coil independent of the rate or" movement of said actuating member, and a spring ,rging said armature into engagement with said actuating member but permitting movement of the latter away from said core while said armature remains in engagement therewith until said spring overcomes said magnetic attraction and pulls said armature away from said core and into engagement with said actuating member thereby to induce a second current in said coil independent of the rate of movement of said actuating member.

9. ina device for sensing a condition and operating an electrical circuit in response thereto, a pair of iron cores each having a coil wound thereon at one end thereof and a permanent magnet between the opposite ends of said cores, an actuating member movable in response to a change in the condition being sensed, an armature opposed to the ends of said cores and movable into and out of engagement therewith, a motion transmitting connection between said armature and said actuating member so that said armature is movable with said actuating member toward said cores until said armature is spaced a predetermined distance from said cores whereupon the magnetic attraction causes said armature to snap into engagement with said cores thereby to induce a current in said coils the vaiue of which is independent of the rate of movement of said actuating member, and a spring connected between said actuating member and said armature for urging said armature into engagement with said actuating member but permitting movement of the latter away from said cores while said armature remains in engagement therewith until the force of said spring overcomes said magnetic attraction to pull said armature away from said cores thereby to again induce a current in said coils the value of which is independent of the rate of movement or said actuating member.

l0. A device according to claim 9 including a spring urging said actuating member away from said cores.

References @Cited in the tile of this patent UNITED STATES PATENTS 3,035,520 Koeppen May 22, 1962

Claims

3. IN A TRANSDUCER FOR SENSING A CONDITION AND OPERATING AN ELECTRICAL CIRCUIT IN RESPONSE THERETO INCLUDING A CORE HAVING A COIL WOUND THEREON AND A PERMANENT MAGNET ASSOCAITED THEREWITH, AN ARMATURE MOVABLE INTO AND OUT OF ENGAGEMENT WITH SAID CORE, AN ACTUATING MEMBER ADAPTED FOR MOVEMENT IN RESPONSE TO CHANGE IN THE CONDITION BEING SENSED, A MOTION TRANSMITTING CONNECTION BETWEEN SAID ARMATURE AND SAID ACTUATING MEMBR SO THAT SAID ARMATURE IS MOVABLE WITH SAID ACTUATING MEMBER TOWARD SAID CORE UNTIL AND ARMATURE A SPACED A PREDETERMINED DISTANCE FROM SAID CORE WHEREUPON THE MAGNETIC ATTRACTION CAUSES SAID ARMATURE TO SNAP INTO ENGAGEMENT WITH SAID CORE THEREBY TO INDUCE A CURRENT IN SAID COIL INDEPENDENT OF THE RATE OF MOVEMENT OF SAID ACTUATING MEMBER.