Electromechanical rotary pawl latch

• US 7,766,397 B2
• Filed: 11/20/2007
• Issued: 08/03/2010
• Est. Priority Date: 11/20/2006
• Status: Active Grant

• Current Assignee: Southco Incorporated (South Chester Tube Company)
• Original Assignee: Southco Incorporated (South Chester Tube Company)
• Inventors: Carabalona, Eric
• Primary Examiner(s): Cuomo; Peter M.
• Assistant Examiner(s): WILLIAMS, MARK A
• Application Number:
  US11/943,350
• Publication Number:
  US 20080252083A1
• Time in Patent Office: 987 Days
• Field of Search: 292/201, 292/216, 292/DIG.23
• US Class Current: 292/201
• CPC Class Codes: E05B 81/14 operating on bolt detents, e.g. for unlatching the bolt
• CPC Class Codes: E05B 81/20 for assisting final closing or for initiating opening
• CPC Class Codes: E05B 81/90 Manual override in case of power failure
• CPC Class Codes: E05B 83/16 Locks for luggage compartments, car boot lids or car bonnets
• CPC Class Codes: E05B 85/02 Lock casings
• CPC Class Codes: Y10T 292/0801 Multiple
• CPC Class Codes: Y10T 292/0854 Cam
• CPC Class Codes: Y10T 292/1082 Motor

Abstract

The present invention is directed to improvements in latch design. The illustrated embodiment of the present invention is a rotary pawl latch with the capability to provide a compressive force between the first member and the second member.

Claims

1. A latch (200) adapted for securing a closure member (300) in a predetermined position, the closure member being provided with a striker (308), the latch comprising:

a latch housing (202);

a pawl (204);

a trigger (206); and

an electrically operated actuator assembly (208) capable of selectively moving said trigger (206) out of engagement with said pawl (204) and retracting said pawl inward relative to said housing (202),

wherein the latch (200) is adapted for attachment to a second member such that the latch can be engaged by the striker (308) for securing the closure member (300) in the predetermined position relative to the second member,

wherein said housing (202) has an opening that allows at least a portion of the striker (308) to enter said housing (202) for engagement by said pawl (204), and

wherein the latch further comprises a support plate (215) supported for rectilinear movement relative to said housing (202), said opening is in the form of a slot (212) that passes through a first portion (211) of said housing (202), such that said slot (212) allows an unobstructed path for the striker (308) to engage said pawl (204) when said pawl is in an open configuration relative to said support plate (215), and said slot (212) is sized such that said housing (202) will not interfere with movement of the striker (308) relative to said housing (202) as said pawl (204) is moved from an open configuration to a closed configuration relative to said support plate (215) by contact with the striker (308) and as said pawl (204) is retracted inward relative to said housing (202) by said electrically operated actuator assembly (208).

2. A latch (200) adapted for securing a closure member (300) in a predetermined position, the closure member being provided with a striker (308), the latch comprising:

a latch housing (202);

a pawl (204);

a trigger (206); and

an electrically operated actuator assembly (208) capable of selectively moving said trigger (206) out of engagement with said pawl (204) and retracting said pawl inward relative to said housing (202),

wherein the latch (200) is capable of assuming a first latched configuration, a second latched configuration and an unlatched configuration, wherein said pawl (204) has first and second teeth (254, 233) provided for engagement by said trigger (206), and wherein said electrically operated actuator assembly (208) comprises;

a support plate (215) supported for rectilinear movement relative to said housing (202), said pawl (204) being pivotally supported by said support plate, said support plate (215) pivotally supporting said trigger (206), said support plate (215) having an elongated slot (226);

a cam gear (218) including a gear wheel (222), a first cam (203), and a second cam (205), said cam gear (218) being rotationally supported in said housing (202) for rotation about an axis of rotation, said first cam (203) having a cam lobe (207) located at a distance from said axis of rotation of said cam gear (218), said first cam (203) selectively tripping said trigger (206), said second cam (205) being eccentrically supported relative to said axis of rotation of said cam gear (218), said elongated slot (226) of said support plate being engaged by said second cam (205) of said cam gear (218), such that rotation of said cam gear (218) causes rectilinear movement of said support plate (215) relative to said housing (202);

a motor (210) selectively powering rotation of said cam gear; and

a sensor (332) mounted on said support plate (215);

wherein said pawl (204) is provided with a pawl slot (258) to capture and hold the striker (308) when said pawl (204) is in either one of a first latched position and a second latched position relative to said support plate (215), wherein with the latch (200) initially in said unlatched configuration, as the closure member (300) is closed, the striker (308) will be positioned and captured in said pawl slot (258) with said pawl (204) being moved to said first latched position relative to said support plate (215),

wherein said sensor (332) is tripped when said pawl (204) reaches said first latched position, when said sensor (332) is tripped a signal is generated that causes electrical current to be supplied to said motor (210) to thereby cause rotation of said cam gear (218) to a latched position corresponding to said first latched configuration in order to move said support plate (215) and said pawl (204) to a retracted position corresponding to said first latched configuration relative to the housing (202).

3. The latch according to claim 2, further comprising:

a second sensor (231) supported by said housing (202) that senses when said cam gear (218) is in a position corresponding to said latched configuration and upon sensing such a condition generates a signal to shut off electrical current to said motor (210).

4. A method for operating the latch of claim 3, wherein the electrical current supplied to the motor (210) has a polarity, the method comprising the steps of:

providing a control circuit for controlling the electrical current to the motor (210); and

reversing the polarity of the electrical current supplied to the motor (210) to rotate the cam gear (218) in a reverse direction when the second sensor (231) fails to signal that the cam gear (218) has reached the position corresponding to the latched configuration after a predetermined interval of time.

5. The latch according to claim 3, wherein said trigger (206) has a notch (290) that receives and engages said the first tooth (254) of said pawl (204) to hold or retain said pawl (204) in said first latched position relative to said support plate (215), and wherein said notch (290) of said trigger (206) receives and engages said second tooth (233) of said pawl (204) to hold or retain said pawl (204) in said second latched position relative to said support plate (215) when said striker (308) moves said pawl (204) to said second latched position with said support plate (215) in a retracted position relative to said housing (202).

6. The latch according to claim 5, further comprising:

a sliding block (352) that is supported for rectilinear movement by said housing (202), said sliding block being capable of selectively engaging said trigger (206) to disengage said trigger from said pawl (204) to thereby release said pawl; and

a Bowden cable (350) connected to said sliding block such that said pawl 204 is released when said Bowden cable is pulled.

7. The latch according to claim 6, wherein said trigger (206) has a first lever arm (284) and a second lever arm (286) that extend approximately along an arc on either side of a pivot axis of said trigger (206), said first lever arm being adapted for engagement by the cam lobe (207) and said second lever arm being adapted for engagement by said sliding block (352).