PLAY-ELIMINATING SETTING APPARATUS

• US 3,636,790 A
• Filed: 10/26/1970
• Issued: 01/25/1972
• Est. Priority Date: 10/24/1969
• Status: Expired due to Term

• Current Assignee: Hermann Bertrang, Horst Spormann
• Original Assignee: Hermann Bertrang, Horst Spormann
• Inventors: Bertrang, Hermann, Spormann, Horst
• Primary Examiner(s): Gerin, Leonard H.
• Application Number:
  US05/084,060
• Time in Patent Office: 456 Days
• Field of Search: 74/409 346/20
• US Class Current: 74/409
• CPC Class Codes: G01P 1/122 Speed recorders
• CPC Class Codes: G04B 35/00 Adjusting the gear train, e.g. the backlash of the arbors, depth of meshing of the gears adjusting the escapement G04B15/12
• CPC Class Codes: Y10T 74/19623 Backlash take-up

Abstract

The rotary pointer, and also a diagram carrier of an indicating and recording apparatus, are driven in a forward direction from a motor through a gear train having two branch gear trains. When the device is manually set in forward direction, play is introduced into the gear trains which is eliminated by biasing means loaded by the gear train during forward movement. During continuous setting in the rearward direction, the biasing means would be untensioned which is prevented by one-way blocking means. A lost-motion device permits rearward setting for an angle of over 180*, and then couples the gear train with the blocking means so that the gear train is blocked after limited rearward setting which negligibly untensions the biasing means.

Claims

1. Play-eliminating setting apparatus, comprising drive means;

rotary means;

a gear train connecting said drive means with said rotary means for turning the same always in the same forward direction so that no play is effective in said forward direction;

setting means connected with said rotary means for turning the same in said forward direction, and also in rearward direction whereby play is introduced into said gear train during setting of said rotary means in said forward direction only;

rotary biasing means operatively connected with said gear train so as to be loaded during rotation of said rotary means in said forward direction and being gradually untensioned during rearward setting;

one-way blocking means for blocking rotation only in said rearward direction; and

lost-motion means between said blocking means and said biasing means and including a stop and abutment means for the same permitting rearward setting of said rotary means with said gear train and biasing means for a predetermined angle before said blocking means blocks said biasing means and thereby said gear train and said setting means so that complete untensioning of said biasing means by continued rearward setting is prevented.

2. Apparatus as claimed in claim 1 wherein said one-way blocking means include a rotary ratchet wheel, and an escapement pawl cooperating with said ratchet wheel.

3. Apparatus as claimed in claim 1 wherein said lost-motion means includes a part-circular slot, wherein the ends of said slot are said abutment means, and are spaced from each other an angle of at least 180*;

and wherein said stop is a pin located in said slot.

4. Apparatus as claimed in claim 3 wherein said part-circular slot extends through an angle of almost 360*.

5. Apparatus as claimed in claim 1 wherein said one-way blocking means include a rotary ratchet wheel, and an escapement pawl cooperating with said ratchet wheel and blocking movement of the same only in said rearward direction;

wherein said ratchet wheel is formed with a part-circular slot having ends forming said abutment means;

wherein said stop is a pin in said slot; and

wherein said biasing means include a biasing gear meshing with said gear train and carrying said pin.

6. Apparatus as claimed in claim 1 wherein said biasing means include a rotary spring housing wheel having an outer biasing gear meshing with said gear train and an inner friction surface, and a spiral spring in said spring housing wheel having an inner fixed end and an outer end slidingly engaging said friction suRface so that said spiral spring is tensioned during rotation of said gear train and of said rotary means with said spring housing wheel in said forward direction, and untensioned during rotation in said rearward direction;

and wherein said lost-motion means connects said spring housing wheel and biasing gear with said one-way blocking means.

7. Apparatus as claimed in claim 6 wherein the transmission ratio between said biasing gear and said gear train is selected so that said rotary means makes almost one revolution in said rearward direction before said lost-motion means moves to an end position in which said blocking means blocks rotation of said spring housing wheel in said rearward direction.

8. Apparatus as claimed in claim 6 wherein said blocking means includes a rotary ratchet wheel, and an escapement pawl cooperating with said ratchet wheel and blocking movement of the same only in said rearward direction;

comprising a shaft supporting said spring housing wheel, biasing gear, and ratchet wheel for rotation about a common axis, and being secured to said spiral spring; and

wherein said lost-motion means include a part-circular slot in one of said wheels concentric with the axis of said shaft and having said abutment means, said stop being a pin secured to the other of said wheels and coupling in one end position at one end of said slot said wheels for turning movement so that rearward rotation of said other wheel is blocked in said end position.

9. Apparatus as claimed in claim 8 wherein said one wheel is said ratchet wheel and is formed with said slot;

wherein said other wheel is said spring housing wheel; and

wherein said slot extends in said ratchet wheel over an arc greater than 180* and less than 360*.

10. Apparatus as claimed in claim 6 wherein said rotary means include a rotary diagram carrier and a rotary pointer;

wherein said gear train includes a first branch gear train connecting said drive means with said diagram carrier, and a second branch gear train connecting said drive means with said rotary pointer;

wherein said setting means includes a setting gear meshing with said second branch gear train; and

wherein said biasing gear meshes with said first branch gear train.