Angular motor shaft with rotational attenuation

Patent metadata

Field	Value
Publication number	US-9853575-B2
Application number	US-201514824241-A
Country	US
Kind code	B2
Filing date	Aug 12, 2015
Priority date	Aug 12, 2015
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

A linear actuator assembly has a linear actuator including a motor shaft extending from a base with a piezoelectric component oscillate the shaft. The shaft has a faceted surface. A movable carriage has a notch with at least one flat surface that receives the shaft of the linear actuator. The carriage is in direct and continuous contact with the motor shaft at the notch such that the motor shaft's facet is in contact with the flat surface of the notch, when the carriage moves linearly along a travel axis. A spring is coupled to the carriage to urge the motor shaft into contact with the notch of the carriage so as to maintain contact between the motor shaft facet and the flat surface of the notch to inhibit rotation of the motor shaft.

First claim

The invention claimed is:

1. A linear actuator assembly comprising: a linear actuator, the linear actuator including a single motor shaft extending from a base; the base including a piezoelectric component to selectively oscillate the motor shaft at an ultrasonic frequency; the motor shaft having a faceted surface which when viewed in cross-section at least a portion of the cross section includes a straight line; a movable carriage, the carriage including a notch to receive the motor shaft; where the notch has substantially a V-shape with at least one flat surface and a relief cutaway configured to reduce the amount of surface area contact between the motor shaft and the at least one flat surface; the carriage being in direct and continuous contact with the motor shaft at the notch wherein the motor shaft's facet is in contact with the flat surface of the notch, when the carriage moves linearly along a travel axis; and a spring assembly coupled to the carriage to urge the motor shaft into contact with the notch of the carriage so as to maintain contact between the motor shaft facet and the flat surface of the notch to inhibit rotation of the motor shaft, the spring assembly contacting the motor shaft at a facet corner configured to reduce the surface area contact between the motor shaft and the spring assembly; wherein the carriage is supported solely by contact with the motor shaft and the spring assembly.

2. The linear actuator assembly according to claim 1 , where the spring comprises a flat cantilever spring coupled to the carriage remote from the notch.

3. The linear actuator assembly according to claim 1 , where the notch is substantially V-shaped, and the motor shaft has a substantially triangle cross-section.

4. The linear actuator assembly according to claim 1 , where the motor shaft has a plurality of faceted surfaces, and where the notch has a plurality of flat surfaces that are in contact with the plurality of faceted surfaces of the shaft.

5. The linear actuator assembly according to claim 1 , where the notch is substantially V-shaped and where the motor shaft has a substantially square cross-section.

6. The linear actuator assembly according to claim 5 , where the motor shaft has a substantially square cross-section with rounded corners.

7. The linear actuator assembly according to claim 1 , where the piezoelectric component is coupled to a flex circuit and where electrical signals are carried by the flex circuit to selectively cause the piezoelectric component to oscillate.

8. The linear actuator assembly according to claim 1 , further comprising:
an optical lens coupled to the carriage to move linearly therewith.

9. The linear actuator assembly according to claim 1 , wherein the relief cutaway comprises a cut back around the bottom of the V-shaped notch.

10. A linear actuator assembly comprising: a linear actuator, the linear actuator including a single motor shaft extending from a base; the base including a piezoelectric component; a flex circuit electrically coupled to the piezoelectric component; where electrical signals are carried by the flex circuit to selectively cause the piezoelectric element to oscillate the motor shaft at an ultrasonic frequency; the motor shaft being substantially square having four facets when viewed in cross-section; a movable carriage, the carriage including a notch to receive the motor shaft; where the notch is substantially V-shaped having two flat surfaces and a relief cutaway configured to reduce the amount of surface area contact between the motor shaft and the at least one flat surface; the carriage being in direct and continuous contact with the motor shaft at the notch wherein two of the motor shaft's facets are in contact with the two flat surfaces of the V-shaped notch, when the carriage moves linearly along a travel axis; and a cantilever spring assembly coupled to the carriage to urge two of the motor shaft's facets into contact with the two flat surfaces of the substantially V-shaped notch of the carriage so as to maintain contact between the motor shaft facets and the flat surfaces of the notch to inhibit rotation of the motor shaft, the spring assembly contacting the motor shaft at a facet corner configured to reduce the surface area contact between the motor shaft and the spring assembly; wherein the carriage is supported solely by contact with the motor shaft and the spring assembly.

11. The linear actuator assembly according to claim 10 , where the motor shaft has a substantially square cross-section with rounded corners.

12. The linear actuator assembly according to claim 10 , further comprising:
an optical lens coupled to the carriage to move linearly therewith.

13. The linear actuator assembly according to claim 10 , wherein the relief cutaway comprises cut back at the upper and lower sides of the V-shaped notch.

14. An autofocus imager comprising: a linear actuator, the linear actuator including a single motor shaft extending from a base; the base including a piezoelectric component to selectively oscillate the motor shaft at an ultrasonic frequency; the motor shaft having a faceted surface which when viewed in cross-section at least a portion of the cross section includes a straight line; a movable carriage, the carriage including a notch to receive the motor shaft; where the notch has substantially a V-shape with at least one flat surface and a relief cutaway configured to reduce the amount of surface area contact between the motor shaft and the at least one flat surface; the carriage being in direct and continuous contact with the motor shaft at the notch wherein the motor shaft's facet is in contact with the flat surface of the notch, when the carriage moves linearly along a travel axis; a spring assembly coupled to the carriage to urge the motor shaft into contact with the notch of the carriage so as to maintain contact between the motor shaft facet and the flat surface of the notch to inhibit rotation of the motor shaft, the spring assembly contacting the motor shaft at a facet corner configured to reduce the surface area contact between the motor shaft and the spring assembly; wherein the carriage is supported solely by contact with the motor shaft and the spring assembly; and a lens coupled to the carriage to move linearly with the linear actuator to adjust a focus of the autofocus imager.

15. The autofocus imager according to claim 14 , where the linear actuator comprises an ultrasonic linear actuator.

16. The autofocus imager according to claim 14 , where the linear actuator assembly includes a chassis and a plurality of elastomeric bushings, at least one elastomeric bushing coupled to the chassis to receive the linear actuator.

17. The autofocus imager according to claim 14 , where the spring comprises a flat cantilever spring coupled to the carriage remote from the notch.

18. The autofocus imager according to claim 14 , where the motor shaft has a plurality of faceted surfaces, and where the notch has a plurality of flat surfaces that are in contact with the plurality of faceted surfaces of the shaft.

19. The autofocus imager according to claim 14 , where the notch is substantially V-shaped and where the motor shaft has a substantially square cross-section.

20. The autofocus imager according to claim 14 , wherein the relief cutaway comprises a cut back around the bottom of the V-shaped notch.

Assignees

• Hand Held Prod Inc

Inventors

• Stang Jean-Pierre
• Puech Jean-Michel
• El Akel Khalid

Classifications

• H02N2/026 Primary

  by pressing one or more vibrators against the driven body · CPC title

• G02B7/08 Primary

  adapted to co-operate with a remote control mechanism · CPC title

• H02N2/04

  Constructional details · CPC title

• G11B7/0937

  Piezoelectric actuators · CPC title

• H02N2/025

  Inertial sliding motors · CPC title