Vehicle body with powered lift type tailgate

• US 5,448,856 A
• Filed: 08/18/1994
• Issued: 09/12/1995
• Est. Priority Date: 08/18/1994
• Status: Expired

• Current Assignee: Chrysler Corporation (Stellantis NV)
• Original Assignee: Chrysler Corporation (Stellantis NV)
• Inventors: Moore, Thomas S., Kowall, David J., DeRees, Delbert D.
• Primary Examiner(s): Cuomo, Peter M.
• Assistant Examiner(s): REDMAN, JERRY E
• Application Number:
  US08/292,662
• Time in Patent Office: 390 Days
• Field of Search: 49/340, 49/339, 49/341, 49/26, 49/28, 49/324, 296/56
• US Class Current: 49/340
• CPC Class Codes: E05F 1/1091 with a gas spring E05F1/1292 takes precedence
• CPC Class Codes: E05F 15/40 Safety devices, e.g. detection of obstructions or end positions
• CPC Class Codes: E05F 15/41 Detection by monitoring transmitted force or torque E05F15/48 takes precedence; Safety couplings with activation dependent upon torque or force, e.g. slip couplings
• CPC Class Codes: E05F 15/611 for swinging wings
• CPC Class Codes: E05F 15/63 operated by swinging arms
• CPC Class Codes: E05Y 2201/236 using force or torque
• CPC Class Codes: E05Y 2800/11 Manual wing operation
• CPC Class Codes: E05Y 2900/546 Tailgates

Abstract

A tailgate is hinged to a passenger van type vehicle body above a substantially vertical rear access opening for swinging movement about a horizontal hinge axis. The tailgate is counterbalanced through its range of movement by spring devices and is opened and closed by a powered actuator mounted on a rear vehicle body pillar. The actuator includes a reversible electric motor driving a worm shaft that drives a worm gear to pivot a crankarm about an axis parallel to the hinge axis. A roller mounted on the crankarm is received in a guide channel that is fixed to the tailgate and extends at right angles to the hinge axis with the pivoting movement of the crankarm thereby translated into swinging tailgate opening and closing movement. The motor is connected with torque sensing circuitry that detects an excessive motor torque demand when the tailgate encounters an obstacle and stops the motor. A normally engaged clutch maintains drive connection between the worm gear and the crankarm to effect normal tailgate opening and closing by the motor and slips to allow manually applied force on the tailgate to open and close same when the motor is not operating.

Claims

1. In combination, a vehicle body having a rear opening, a tailgate adapted to open and close said rear opening, a hinge pivotally mounting said tailgate on said vehicle body for swinging movement about a horizontal hinge axis located adjacent an upper edge of said tailgate so that said tailgate on upward lifting movement is moveable from a closed position closing said rear opening to an open position completely opening said rear opening, a pair of counterbalance devices operatively connected between said vehicle body and said tailgate substantially counterbalancing the weight of said tailgate as it swings to open and close said rear opening, a singular tailgate actuator mechanism mounted on said vehicle body adjacent said upper edge of said tailgate and operatively connected to said tailgate, said actuator mechanism comprising a reversible electric motor, a crankarm pivotal in an arc transverse to said hinge axis, torque multiplying drive means including a normally engaged clutch operatively connecting said motor to said crankarm, a guide channel mounted on and extending along an inner side of said tailgate transfer to said hinge axis, a roller mounted on said crankarm and received and retained in said guide channel, said guide channel having opposing guide rails engaged by said roller at diametrically opposite locations thereby to effect movement of said tailgate between said closed and open positions by said roller rolling in said guide channel on pivotal movement of said crankarm in opposite directions by said motor, said clutch having a load capacity sufficient to effect normal tailgate opening and closing by said motor and to slip to allow an external force on said tailgate to open and close same independent of motor operation, and a controller controlling said motor that detects an excessive amount of motor torque demand when said tailgate encounters an obstacle during motor powered movement and stops the motor before slippage in the clutch occurs.

2. In combination, a vehicle body having a substantially vertical rear opening, a tailgate adapted to open and close said rear opening, a hinge pivotally mounting said tailgate on said vehicle body for swinging movement about a horizontal hinge axis located adjacent an upper edge of said tailgate so that said tailgate on upward lifting movement is moveable from a closed substantially vertical position closing said rear opening to an open upwardly angled position above horizontal completely opening said rear opening, a pair of gas springs operatively connected between said vehicle body and said tailgate substantially counterbalancing the weight of said tailgate as it swings to open and close said rear opening, a singular tailgate actuator mechanism mounted on said vehicle body adjacent said upper edge of said tailgate and operatively connected to said tailgate, said actuator mechanism comprising a reversible DC constant speed motor, a crankarm pivotal in an arc at right angles to said hinge axis, drive means operatively connecting said crankarm to said motor including a worm shaft connected to be driven by said motor, a worm gear driven by said worm shaft, a torque multiplying gear train operatively connected to pivot said crankarm, a normally engaged clutch connecting said worm gear to said gear train, a guide channel mounted on and extending along an inner side of said tailgate at right angles to said hinge axis, a roller mounted on said crankarm and received and retained in said guide channel, said guide channel having opposing guide rails extending longitudinally at right angles to said hinge axis and extending width wise parallel to said hinge axis and engaged by said roller at diametrically opposite locations thereby to effect movement of said tailgate between said closed and open positions by said roller rolling in said guide channel on pivotal movement of said crankarm in opposite directions by said motor, said clutch having a load capacity sufficient to effect normal tailgate opening and closing by said motor and to slip against the reaction force of said worm shaft to allow an external force on said tailgate to open and close same, and a controller controlling said motor that detects an excessive amount of motor torque demand when said tailgate encounters an obstacle during motor powered movement by sensing motor current load and stops the motor before slippage in the clutch occurs.

3. A combination as set forth in claim 2, and said vehicle body having a rear pillar adjacent said rear opening, said rear pillar having an upper end, and said actuator mechanism except for said guide channel wholly mounted on said rear pillar near said upper end.

4. A combination as set forth in claim 3, and said tailgate having a window and said guide channel mounted between a side edge of said tailgate and said window.