Projector tilt mechanism

• US 3,968,949 A
• Filed: 07/18/1974
• Issued: 07/13/1976
• Est. Priority Date: 07/18/1974
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Romano, Frank A. Jr.
• Primary Examiner(s): Frazier, Roy D.
• Assistant Examiner(s): Hafer, Robert A.
• Application Number:
  US05/489,759
• Time in Patent Office: 726 Days
• Field of Search: 248/11, 248/23, 248/188.2, 248/188.4, 248/184, 248/185, 248/186, 248/371, 248/397, 74/89.15
• US Class Current: 248/650
• CPC Class Codes: F16M 11/10 around a horizontal axis F16M11/12 takes precedence
• CPC Class Codes: F16M 11/18 with mechanism for moving the apparatus relatively to the stand
• CPC Class Codes: G03B 21/145 Housing details, e.g. position adjustments thereof

Abstract

A projector tilt mechanism includes a base about which a load-carrying platform is rotated in a vertical plane. A threaded shaft is rotatably coupled to the platform by radial thrust bearings and to the base by threaded fittings. Lost motion in the rotational system is avoided by properly positioning and locking in place two threaded nuts along the shaft at either side of the threaded connection to the base, and by using threaded locking collars tightened against the outermost thrust bearing faces. Rotation of the shaft produces relative rotation of the platform and base, causing the base to raise the front or rear of the projector above a flat surface or, if the base is affixed to a pedestal, causing a direct change in platform pitch.

Claims

1. A mechanism having a platform for tilting a load carried on said platform, comprising:

a threaded shaft;

support means engaging said shaft and coupled to said platform so as to maintain said platform generally at a predetermined position with respect to said shaft;

a base, having first and second ends, said base being pivotable about said first end thereof for affecting movement of said platform in a first direction, said base being pivotable about said second end thereof for affecting movement of said platform in a second direction, said base pivoting responsive to the rotation of said shaft; and

threaded means pivotably mounted about an axis at a first location upon said base so as to be free to rotate through a first plane substantially orthogonal to said axis, said threaded means engaging said threaded shaft, said threaded means and said threaded shaft being rotatable relative to each other,

said platform being pivotally mounted at a second location upon said base, spaced apart from said first location so as to be free to rotate through a second plane substantially parallel to said first plane.

2. The mechanism of claim 1 wherein said shaft is relatively rotatable with respect to said support means.

3. The apparatus of claim 1 wherein said platform is situated above said threaded shaft, and said second location on said base is located below said first location on said base.

4. The apparatus of claim 2 wherein said platform is situated above said threaded shaft, and said second location on said base is located below said first location on said base.

5. The apparatus of claim 2 including means coupled to one end of said threaded shaft for imparting rotational motion to said shaft.

6. The apparatus of claim 4 including means coupled to one end of said threaded shaft for imparting rotational motion to said shaft.

7. The apparatus of claim 1 wherein said threaded means comprises two threaded fittings, each fitting being separately positionable along said shaft to minimize lost motion between said threaded means and said shaft.

8. The apparatus of claim 2 wherein said threaded means comprises two threaded fittings, each fitting being separately positionable along said shaft to minimize lost motion between said threaded means and said shaft.

9. The apparatus of claim 6 wherein said threaded means comprises two threaded fittings, each fitting being separately positionable along said shaft to minimize lost motion between said threaded means and said shaft.

10. The apparatus of claim 9 including means affixed to said shaft on either side of said support means, and thrust bearings situated between said support means and each of said means affixed to said shaft, said thrust bearings being urged against said support means on either side thereof by said means affixed to said shaft on either side of said support means, respectively.

17. The apparatus of claim 10, further including means for holding said base in a fixed position, whereby said base independently supports and tilts said platform about said second location.

11. A projector tilt mechanism having a frame for supporting a projector thereon with selectable pitch, comprising:

a threaded shaft rotatable about its longitudinal axis;

support means coupling said shaft to said frame so as to maintain said frame generally at a predetermined position with respect to said shaft, said shaft being free to rotate with respect to said support means;

a base, having first and second ends, said base being pivotable about said first end thereof for affecting movement of said frame in a first direction, said base being pivotable about said second end thereof for affecting movement of said frame in a second direction, said base pivoting responsive to the rotation of said shaft; and

threaded means pivotally mounted about an axis at a first location upon said base so as to be free to rotate through a plane substantially orthogonal to said axis, said threaded means engaging said threaded shaft,

said frame being pivotally mounted at a second location upon said base, spaced vertically apart from said first location so as to be free to rotate through a second plane.

12. The apparatus of claim 11 wherein said frame is situated above said threaded shaft and said second location on said base is located below said first location on said base.

13. The apparatus of claim 12 including means coupled to one end of said threaded shaft for imparting rotational motion to said shaft.

14. The apparatus of claim 11 wherein said threaded means comprises two threaded fittings, each fitting being separately positionable along said shaft to minimize lost motion between said threaded means and said shaft.

15. The apparatus of claim 13 wherein said threaded means comprises two threaded fittings, each fitting being separately positionable along said shaft to minimize lost motion between said threaded means and said shaft.

16. The apparatus of claim 15 including means affixed to said shaft on either side of said support means, and thrust bearings on said shaft situated between said support means and each of said means affixed to said shaft, said thrust bearings being urged against said support means on either side thereof by said means affixed to said shaft on either side of said support means, respectively.

18. The apparatus of claim 16, further including means for holding said base in a fixed position, whereby said base independently supports and tilts said frame about said second location.