Encoder for altimeters and the like instruments

Abstract

An inexpensive, compact and yet highly accurate instrument for transmitting coded signals representing altitudes at which an aircraft is flying, the instrument comprising an altitude sensing unit and a separate encoding unit operatively connected to the sensing unit with means for finely and precisely adjusting the encoding unit relative to the altitude sensing unit.

I claim: 
     
       1. Encoding means for altimeters or the like comprising a frame,   a fluid pressure actuated device including a drive gear rotatably supported by said frame;   an encoding device including an encoder disc and a pinion connected to said encoder disc;   said pinion being engageable with said gear,   a support for said encoding device,   means on said frame forming a bearing,   an adjusting member supported by said bearing for rotational adjustment about the axis of said bearing,   said adjusting member supporting said support with the axis of said pinion eccentric to the axis of said bearing whereby said adjustment of said adjusting member will adjust said pinion relative to said gear, and   means for sensing the position of said encoder disc relative to said support.   
     
     
       2. Encoding means as defined in claim 1 wherein said adjusting member comprises a ring surrounding said support. 
     
     
       3. Encoding device as defined in claim 1 wherein said encoding device comprises a shaft supporting said encoder disc and said pinion said support comprising   a housing having counterbore concentric with the axis of said bearing, and   a housing part removably fitted in said counterbore,   said housing and said housing part rotatably supporting opposite ends of said shaft.   
     
     
       4. Encoding means for altimeters or the like comprising a frame,   a fluid pressure actuated device including a drive gear rotatably supported by said frame;   an encoding device including an encoder disc and a pinion connected to said encoder disc;   said pinion being engageable with said gear,   a support for rotatably supporting said pinion and said encoder disc,   means on said frame forming a first bearing,   an adjusting member supported by said first bearing for rotational adjustment about the axis of said first bearing,   said adjusting member having a second bearing eccentric to said first bearing,   said second bearing supporting said support for rotational adjustment about the axis of rotation of said pinion and said encoder disc whereby said adjustment of said adjusting member will adjust said pinion relative to said gear, and   means on said support for sensing the position of said encoder disc.   
     
     
       5. Encoding means as defined in claim 4 comprising means for locking said support and said adjusting member in different adjusted positions. 
     
     
       6. An encoding means as defined in claim 4 comprising a single locking device for concurrently locking said support and said adjusting member in different adjusted positions.   
     
     
       7. Encoding means as defined in claim 4 wherein said adjusting member comprises a ring surrounding said support.   
     
     
       8. Encoding means as defined in claim 4 wherein said support comprises a housing substantially enclosing said encoder disc.   
     
     
       9. Encoding means as defined in claim 8 wherein said ring supports said housing. 
     
     
       10. Encoding means as defined in claim 8 wherein said frame supports said ring and said ring supports said housing. 
     
     
       11. Encoding means as defined in claim 4 wherein said encoding device comprises a shaft supporting said encoder disc and said pinion,   a support comprising a housing having a counterbore concentric with said axis of said second bearing, and   a housing part fitted in said counterbore,   said housing and said housing part rotatably supporting opposite ends of said shaft.   
     
     
       12. Encoding means as defined in claim 11 wherein said housing has a second counterbore concentric with the axis of said second bearing, a printed circuit board fitted in said second counterbore, and   means forming electrical connections between said circuit board and said sensing means. .Iadd. 13. An altitude indicating device comprising   a pressure actuated device including a drive gear rotatably supported by said frame;   an encoding device including an encoder disc and a pinion connected to said encoder;   said pinion being engageable with said gear,   a support supporting said disc and said pinion for rotation about an axis,   means on said frame for adjusting said support transversely relative to said axis whereby to adjust said pinion relative to said gear, and   means on said support for sensing the position of said encoder disc relative to said support,   said support being adjustable about said axis, and   said altitude indicating device being devoid of altitude indicating means other than said encoding device. .Iaddend.