Variable capacitor with gear train end stop

• US 4,390,924 A
• Filed: 05/12/1981
• Issued: 06/28/1983
• Est. Priority Date: 05/12/1981
• Status: Expired due to Term

• Current Assignee: Rockwell International Corporation
• Original Assignee: Rockwell International Corporation
• Inventors: Nebiker, Herman Jr.
• Primary Examiner(s): Goldberg, Elliot A.
• Application Number:
  US06/262,735
• Time in Patent Office: 777 Days
• Field of Search: 188/68, 188/82.8, 188/74, 192/142 A, 361/279, 361/289
• US Class Current: 361/279
• CPC Class Codes: H01G 5/01 Details

Abstract

An energy absorbing mechanical end stop for a high speed gear train that is used to drive a variable vacuum capacitor utilizes a friction plate that is mounted to a gear member of the high speed gear train as an energy absorbing mechanism. A wedge member is activated when the tuning of the variable vacuum capacitor approaches a limit and falls between the friction plate and the gear member to which the friction plate is attached. The friction between the friction plate and the wedge member brings the gear member to a stop without damaging the high speed gear train or the variable vacuum capacitor that is driven by the high speed gear train.

Claims

1. In combination, a variable vacuum capacitor with a tuning shaft connected to a motor driven drive train for rotating the tuning shaft varying the capacitance of the variable vacuum capacitor thereby, the motor driven drive train having at least a first drive means and an energy absorbing means comprising;

a friction plate;

a mounting means for mounting the friction plate to the first drive means and separating the mounted friction plate from first drive means by first predetermined distance;

a wedge member of a thickness that is at least equal to the first predetermined distance; and

activate means for placing the wedge member between the friction plate and the drive means so that, when the first drive means is rotating and the wedge member is placed betweeen the friction plate and the first drive means, the friction between the wedge member and the friction plate acts to retard the rotation of the first drive means.

2. The energy absorbing mechanical means according to claim 1 wherein the first drive means comprises;

a pinion;

a motor with a drive shaft mounted to the pinion; and

the first drive means being a gear that interfaces to the pinion and the tuning shaft so that for every 360°

travel by the first drive means the tuning shaft travels 360°

.

3. The energy absorbing mechanical means according to claims 1 or 2 wherein the friction plate and the mounting means comprises;

a metal plate shape as a half disc with a radius that is less than the radius of the first drive means;

a spacer plate having the shape of a half disc with a radius that is less than the friction plate; and

fastner means for securing the friction plate, and spacer plate to the first drive means such that there centers of the friction plate, spacer plate and drive metal are in alignment and a clearance is provided between the outer parameter of the spacer plate and the outer parameter of the friction plate for passage of the wedge member.

4. The energy absorbing mechanical means according to claim 1 wherein the friction plate and the mounting means comprise;

a first plate made of a flexible metal to serve as the friction plate;

a second plate of a thickness less than the thickness than the wedge member such that when the first plate is mounted on the second plate the first plate when the wedge member is in place between the first plate and the first drive means the spring forces associated with the flexible metal that the first plate is made of enhances the friction to the surface of the wedge member that is in contact with the first plate.

5. The energy absorbing mechanical means according to claim 4 wherein the first plate further comprises;

a ramp surface along the radius of the first plate that has a width from the outer circumference of the first plate to the outer circumference of the second plate when both the first plate and the second plate are mounted on the first drive means.

6. The energy absorbing mechanical means according to claims 1 or 2 wherein the activate means comprises;

a fist idler shaft;

a converting gear train means for converting the number of turns made by the first drive means to tune the variable vacuum capacitors between a minimum limit and maximum limit into a single revolution as represented by a single turn of the first idler shaft;

a cam means mounted to the first idler shaft having a first surface and a second surface with the first surface being higher than the second surface; and

caster means mounted to the wedge member and in alignment so that the caster means on the first surface and the second surface causing the wedge member to be in an elevated position when the caster means on the first surface and to be in nonelevated position when the caster rides on the second surface so that the wedge member will become engaged with the friction plate when the caster rides along the second surface.

7. The energy absorbing mechanical means according to claim 6 further comprising;

a limit switch driven by the first idler shaft for removing power from the motor when the variable vacuum tuning capacitor is tuned to a limit.

8. The energy absorbing mechanical means according to claims 1 or 2 wherein the activate means comprises;

a first idler shaft;

a converting gear train means for converting the number of turns made by the first drive means to tune the variable vacuum capacitor between a maximum limit and a minimum limit into a single revolution as represented by a single turn of the first idler shaft;

a limit switch driven by the first idler arm for removing power from the motor when the variable vacuum capacitor is tuned to a limit;

a solenoid means activates by the limit switch and connected to the wedge member for placing the wedge member between the friction plate and the drive means.

9. A drive train having at least a first drive means and an energy absorbing means comprising an end stop;

a friction plate;

a mounting means for mounting the friction plate to the first drive means and separating the mounted friction plate from the first drive means by first predetermined distance;

a wedge member of a thickness that is at least equal to the first predetermined distance; and

activate means for placing the wedge member between the friction plate in the drive means so that, when the first drive means is rotating and the wedge member is placed between the friction plate and the first drive means, the friction between the wedge member and the friction plate acts to retard the rotation of the first drive means.

10. The energy absorbing means according to claim 9, wherein the first drive means comprises;

a pinion;

a motor with a drive shaft mounted to the pinion;

the first drive means being a gear that interfaces with the pinion.

11. The energy absorbing means according to claims 9 and 10 wherein the friction plate and the mounting means comprises;

a metal plate shape as a half disc with a radius that is less than the radius of the first drive means;

a spacer plate having the shape of a half disc with a radius that is less than the friction plate; and

fastener means for securing the friction plate spacer plate to the first drive means such that the centers are in alignment and a clearance is provided between the outer parameter of the spacer plate and the outer parameter of the friction plate for passage of the wedge member.

12. The energy absorbing means according to claim 9 wherein the friction plate and the mounting means comprise;

a first plate made of a flexible metal to serve as the friction plate;

a second plate of a thickness less than the thickness than the wedge member such that when the first plate is mounted on the second plate the first plate when the wedge member is in place between the first plate and the first drive means the spring forces associated with the flexible metal that the first plate is made of enhances the friction to the surface of the wedge member that is in contact with the first plate.

13. The energy absorbing means according to claim 12 wherein the first plate further comprises;

a ramp surface along the radius of the first plate that has a width from the outer circumference of the first plate to the outer circumference of the second plate when both the first plate and the second plate are mounted on the first drive means.