Rotary Pawl Latch

• US 20090235767A1
• Filed: 03/10/2009
• Published: 09/24/2009
• Est. Priority Date: 03/10/2008
• Status: Active Grant

• Current Assignee: Southco Incorporated (South Chester Tube Company)
• Original Assignee: Southco Incorporated (South Chester Tube Company)
• Inventors: Mengstab, Evan, Garneau, Gregory Gilbert
• Granted Patent: US 8,496,275 B2
• Time in Patent Office: Days
• US Class Current: 74/56
• CPC Class Codes: E05B 2047/0016 with linearly reciprocating motion
• CPC Class Codes: E05B 2047/0024 Cams
• CPC Class Codes: E05B 47/0012 with rotary electromotors actuators with rotary electromotors per se H02K7/06, H02K23/68
• CPC Class Codes: E05B 65/46 for drawers
• CPC Class Codes: E05C 3/24 in the form of a bifurcated member automatic catches with a bifurcated latch E05C19/024; locks with a bifurcated bolt E05B65/0046, E05B85/243
• CPC Class Codes: Y10T 292/1021 Motor
• CPC Class Codes: Y10T 292/1082 Motor
• CPC Class Codes: Y10T 292/11 Magnetic
• CPC Class Codes: Y10T 74/18304 Axial cam

Abstract

A latch including a housing, a rotary pawl, catch means for releasably holding the pawl in a closed configuration, and means for operating the catch means are disclosed.

Claims

1. An electrically operated actuator assembly comprising:

a housing;

a motor provided in said housing;

a plunger movable between an extended position and a retracted position; and

a cam that rotates when said motor is energized, said cam having at least one cam surface that can engage said plunger such that said plunger moves between said retracted position and said extended position in response to rotation of said cam.

2. The actuator assembly of claim 1, wherein said at least one cam surface is formed by a pair of cam ramps, each of said cam ramps has an apex and a bottom, and when said motor is energized, said cam rotates causing said plunger to ride up said cam ramps such that said plunger will move between its retracted position and its extended position.

3. The actuator assembly of claim 2, wherein said plunger has a pair of plunger ramps, each of said plunger ramps has an apex and a bottom, and said plunger ramps mate with said cam ramps when said motor is not energized such that said apex of each of said plunger ramps seats against said bottom of a respective one of said cam ramps.

4. The actuator assembly of claim 3, wherein when said motor is energized, said cam rotates causing said plunger ramps to ride up said cam ramps such that said plunger will move between its retracted position and its extended position, and said plunger cannot rotate relative to said housing.

5. The actuator assembly of claim 4, wherein when said motor is energized, said cam continues to rotate at least until said bottom of each said cam ramp is in registry with said apex of a respective one of said plunger ramps such that said plunger is free to move back to a position that said plunger was in prior to said motor being energized.

6. The actuator assembly of claim 5, wherein said electrically operated actuator assembly further comprises:

a reduction gear system that reduces a torque output required of said motor.

7. A latch assembly for releasably securing a first member in a closed position relative to a second member, one of said first member and said second member having a keeper in a fixed positional relationship therewith, the latch assembly comprising:

a latch housing;

a pawl pivotally attached to the latch housing and being movable between a closed position and an open position, the pawl being provided with a torsion spring member that biases the pawl toward the open position;

a catch movable between an engaged position and a disengaged position, said catch engaging said pawl at an engagement position when said pawl is in said closed position and said catch is in said engaged position; and

an actuator assembly for selectively moving said catch out of engagement with said pawl, wherein said actuator assembly includes a plunger that pushes said catch to release said pawl from its closed position as said plunger moves toward an extended position.

8. The latch assembly according to claim 7, wherein said catch forms an elongated lever that is pivotally supported in said latch housing near one of its ends, said catch engages said pawl at a point intermediate a pivot axis of said catch and a location on said catch where said plunger contacts said catch and said location on said catch where said plunger contacts said catch is as far away as possible from said pivot axis of said catch, such that said catch provides a mechanical advantage to said plunger due to said catch forming said elongated lever in order to reduce a torque output required of said motor.

9. The latch assembly according to claim 8, wherein said pawl has an elongated pawl arm and said pawl arm is engaged by said catch to retain said pawl in said closed position to thereby further reduce said torque output required of said motor.