OSCILLATING MECHANISM

• US 3,671,766 A
• Filed: 06/29/1970
• Issued: 06/20/1972
• Est. Priority Date: 06/29/1970
• Status: Expired due to Term

• Current Assignee: Spencer D. Howe
• Original Assignee: Spencer D. Howe
• Inventors: Spencer, D. Howe
• Primary Examiner(s): J. D. Miller
• Assistant Examiner(s): B. A. Reynolds
• Application Number:
  US05/056,094
• Time in Patent Office: 722 Days
• Field of Search: 310/36-39,49,15,28,29,31-35,69,164 318/134,119,120,126-129 340/146.3 356/93,95,97 350/6,266 335/272,274,276,69,75,76,138,219,235,288
• US Class Current: 310/39
• CPC Class Codes: H02K 33/10 wherein the alternate energisation and de-energisation of the single coil system is effected or controlled by movement of the armatures

Abstract

The invention teaches a mirror oscillating through an angular arc defined by arc terminal points. Springs associated with the mirror absorb the kinetic energy of halt at the terminal points and provide the primary driving force and energy to the mirror for reversing the direction of oscillation thereof toward the opposing terminal point. Magnetic means provides a source force to induce oscillation from dead stop and to supplement the spring action by compensating for frictional and other energy losses during operation. Means are provided to bias the mirror to one of the terminal positions when inoperative. The mirror is powered at each terminal point and freely moves at a substantially constant angular velocity between the terminal points. This invention relates to an arrangement for oscillating an element, such as a reflecting surface, back and forth in an arcuate path at a substantially constant angular velocity through a major arc segment.

Claims

1. In a scanning device operable to move a scanning element in oscillating mode through a determined arc of travel, the combination of pivot means to accommodate said oscillating movement, combination means to initiate said oscillating movement at device start up and to maintain said oscillating movement during device operation, said combination means comprising a rotor carried by the oscillating element adjacent one end thereof, a magnetic core in a housing adjacent the rotor, coil means surrounding the magnetic core and internally of the housing, said housing being connected to said magnetic core and having a peripheral flange telescopically receiving said rotor, bosses on the peripheral flange operative to emanate magnetic flux when said coil is electrically energized, other bosses on the rotor of magnetically attractive material alignable with the bosses on the peripheral flange when the scanning element is at midpoint in its cycle of oscillation, spring means having first and second cantilever arm portions carried by the scanning element, said first and second cantilever arm portions being respectively alternately abuttable with first and second fixed electrical contacts at the terminal points of the arc of motion of said element, the engagement between a contact on said spring means and one of said fixed contacts being operable to close an electric circuit through said coil and thereby induce the creation of a magnetic field, the physical engagement between said first and second cantilever arm portions and the respective first and second fixed contacts being operable to alternately flex said spring means and store therein most of the kinetic energy of motion of said oscillating scanning element, said stored energy being releasable by said spring means upon termination of movement of said scanning element in either direction to thereby provide a mechanical biasing force to induce reverse motion of said scanning element, the magnetic field created by the engagement between the contact on said spring means and one of said fixed contacts being operable to create a magnetic biasing force to induce reverse motion of said scanning element, and means to bias said scanning element to a terminal point in its arc of movement upon device shutdown.

2. A scanning device operable to move a scanning element in oscillating mode through a determined arc of travel according to claim 1, wherein said last mentioned means comprises a flexure pivot at one end of said element supporting the element for oscillatory motion, said flexure pivot being slightly pre-stressed to provide a small biasing force to move the scanning element to a terminal point in its arc of movement upon device shutdown.

3. In a scanning device operable to move a scanning element in oscillating mode through a determined arc of travel according to claim 1, wherein said last mentioned means comprises a pivot on one end of said scanning element to accommodate said oscillating motion, a rotor carried by said last mentioned end of said scanning element, a second housing adjacent said last mentioned end of said scanning element, a permanent magnet within said second housing, bosses on the second housing to emanate the magnetic field created by said permanent magnet, other magnetically attractive bosses on the rotor physically disposed within the field created by said magnet, the bosses on said rotor having a peripheral dimension equal to about one-half of the peripheral dimension of the spaces separating the bosses on the housing, the bosses on the rotor being radially alignable with the bosses on the housing when the scanning element is at any terminal point in its arc of movement upon device shutdown.

4. An oscillating mirror system comprising:

electromagnetic apParatus including a cylindrical magnetic core having first and second end portions, an annular electrical coil surrounding the first end portion of said magnetic core, and an annular stator surrounding the second end portion of said core, first and second electrical contacts, a power source operatively coupled to said first and second electrical contacts, a mirror assembly rotatably mounted on said second end portion, and along the longitudinal axis, of said magnetic core, said mirror assembly including a mirror, a rotor fixedly coupled to said mirror and having an annular portion interposed between said annular stator and said second end portion of said magnetic core, and a leaf spring member operatively coupled to said rotor and having first and second cantilever arm portions adapted to alternately contact the respective first and second electrical contacts for periodically energizing said electrical coil and thereby periodically creating a magnetic field between said second end portion of said magnetic core and said annular stator, said magnetic field serving to motivate bidirectional rotary movement of said mirror assembly.

5. The apparatus defined by claim 4 wherein said annular stator is adapted to have a plurality of radially extending portions along the internal periphery thereof, and said rotor is adapted to have a plurality of radially extending portions along the external periphery thereof, the number of radially extending portions on said annular stator and said rotor being equal.

6. The apparatus defined by claim 4 wherein said mirror assembly is rotatably mounted on said second end portion of said magnetic core by a flexure pivot adapted to mechanically bias one of said first and second cantilever arm portions to be in physical contact with an associated one of said first and second electrical contacts when said electromagnetic apparatus is de-energized.

7. A mechanism including an element oscillable in limit cycle at a substantially uniform velocity between a pair of terminals, primary energy storage means couplable to said element only at said terminals for receiving, storing and returning kinematic energy to said element during the time of respective contact with said terminals and for driving said element from a first of said terminals toward a second of said terminals and secondary driving means coupled to said element and acting in conjunction with said primary energy storage means for overcoming energy losses during oscillation of said element.

8. A mechanism including an element oscillable through an arc and alternately contactable with a pair of terminals positioned at the ends of the arc, and motive means couplable to said element upon contact thereof alternately with said terminals and operative only during duration of the contact to impart energy to said element for movement thereof from a first of said terminals toward a second of said terminals.

9. A mechanism as in claim 8 wherein said motive means includes primary energy storage means to receive, store, and return the greater portion of the energy to said element at each end of the cycle and secondary motive means to overcome energy losses during oscillation of said element.

10. A mechanism as in claim 9 wherein said primary energy storage means comprises spring means biasable to store energy in and to subsequently release energy from said element upon the contact thereof alternately with said terminals.

11. A mechanism as in claim 10 wherein said secondary motive means comprises an electromechanical actuator and two pairs of electrical contacts respectively positioned on said element and on said terminals for alternate energization of said actuator upon the contact of said element alternatively with said terminals.

12. A mechanism as in claim 11 further including biasing means coupled to said element and said terminals for biasing said element at one of said terminals when said element is at rest.

13. A mechanism as in claim 10 wherein said spring means comprises a pair of cantilever arms secured to said element and alternatively contactable with said terminals.

14. A mechanism is in claim 9 wherein said secondary motive means comprises an electromechanical actuator energizable only upon the contact of said element alternatively with said terminals.

15. A mechanism including an element oscillable through an arc and alternately contactable with a pair of terminals positioned at the ends of the arc, and motive means couplable to said element upon contact thereof alternately with said terminals and operative upon the contact to impart energy to said element for movement thereof from a first of said terminals toward a second of said terminals;

said motive means including primary motive means to impart the greater portion of the energy to said element and secondary motive means to overcome energy losses during oscillation of said element;

said secondary motive means comprising an electromechanical actuator energizable upon the contact of said element alternatively with said terminals; and

said actuator comprising a rotor mounted on said element and a stator mounted on a support, said terminals secured to said support, said rotor and said stator having cooperative bosses with spacing therebetween for carrying a magnetic field.