Pallet dock lift

In an ambulatory dock lift having a base and a loading platform which can be vertically raised and lowered with respect to said base, the improvement comprising a retractable throw-over bridge system for joining the loading platform to an adjacent loading surface such as a truck bed or the like, said bridge system comprising:

• an elongate bridge member joined at a pivot point to one end of said loading platform and being pivotal between an upright retracted position and a lowered position, and having a selected length so that said bridge member will span a selected space between the loading platform and an adjacent loading surface;
• a bridge retractor assembly joining said bridge member to said platform, said retractor assembly being connected to said bridge member at a selected lifting point and including biasing means adapted for applying a lifting force to said bridge member to pivot said bridge member upwardly starting from a position intermediate said retracted and lowered positions to said upright retracted position thereby providing a stop gate across said one end of said loading platform;
• said bridge retractor assembly and bridge member being arranged so that said lifting force is initially insufficient to pivot said bridge member upwardly from said lowered position and becomes sufficient to pivot said bridge member automatically to said retracted position when, through external forces, said bridge member is pivoted upwardly and reaches said intermediate positon;
• connecting means for joining said biasing means to said bridge member at said lifting point;
• dampening means associated with said biasing means for dampening the pivotal movement of said bridge member between said retracted position and said lowered position;
• and
• said retractor assembly comprising an overload shock absorber which incorporates said biasing means and said dampening means.

In an ambulatory dock lift having a base and a loading platform which can be vertically raised and lowered with respect to said base, the improvement comprising a retractable throw-over bridge system for joining the loading platform to an adjacent loading surface such as a truck bed or the like, said bridge system comprising:

• an elongate bridge member joined at a pivot point to one end of said loading platform and being pivotal between an upright retracted position and a lowered position, and having a selected length so that said bridge member will span a selected space between the loading platform and an adjacent loading surface;
• a bridge retractor assembly joining said bridge member to said platform, said retractor assembly being connected to said bridge member at a selected lifting point and including biasing means adapted for applying a lifting force to said bridge member to pivot said bridge member upwardly starting from a position intermediate said retracted and lowered positions to said upright retracted position thereby providing a stop gate across said one end of said loading platform;
• said bridge retractor assembly and bridge member being arranged so that said lifting force is initially insufficient to pivot said bridge member upwardly from said lowered position and becomes sufficient to pivot said bridge member automatically to said retracted position when, through external forces, said bridge member is pivoted upwardly and reaches said intermediate positon;
• connecting means for joining sad biasing means to said bridge member at said lifting point;
• dampening means associated with said biasing means for dampening the pivotal movement of said bridge member between said retracted position and said lowered position;
• and
• said connecting means comprising an elongated connector and wherein said retractor assembly comprises an overload shock absorber having spring means to apply a biasing force in a selected direction to said connector, said assembly further including dashpot means to dampen said biasing force applied to said connector and pulley means to control the movement of said connector as said bridge member moves beween said retracted and lowered positions.

In an ambulatory dock lift having a base and a loading platform which can be raised and lowered with respect to said base, the improvement comprising a retractable throw-over bridge system for joining the loading platform to an adjacent loading surface such as a truck bed or the like, said bridge system comprising:

• an elongate bridge member of a predetermined weight joined at a pivot point to one end of said loading platform and being pivotal between an upright retracted position through an intermediate position above the horizontal and lowered position below horizontal, and having a selected length so that said bridge member will span a selected space between the loading platform and an adjacent loading surface;
• a bridge retractor assembly joining siad bridge member to said platform, said retractor assembly including biasing means for applying a lifting force to said bridge member at a selected lifting point to bias said bridge member upwardly toward said upright retracted position;
• said lifting force of said biasing means being of a value in relation to the weight of said bridge member such that said lifting force is initially insufficient to pivot said bridge member upwardly from said lowered position and becomes sufficient to pivot said bridge member automatically to said retracted position when, through external forces, said bridge member is pivoted upwardly and reaches said intermediate position.

In an ambulatory dock lift having a base and a loading platform which can be raised and lowered with respect to said base, the improvement comprising a retractable throw-over bridge system for joining the loading platform to an adjacent loading surface such as a truck bed or the like, said bridge system comprising:

• an elongate bridge member of a predetermined weight joined at a pivot point adjacent one end thereof to one end of said loading platform and being pivotal between an upright retracted position through an intermediate position and a lowered position, and having a selected length so that said bridge member will span a selected space between the loading platform and an adjacent loading surface;
• a bridge retractor assembly joining said bridge member to said platform, said retractor assembly including biasing means for applying an upward lifting force to said bridge member at a selected lifting point spaced outwardly of said pivot point to bias the bridge member upwardly toward said upright retracted position;
• said lifting force of said biasing means being directed along a line constantly located above said pivot point at said one end of said bridge member when the bridge member is in any of said positions, and said lifting force being of a value in relation to the weight of said bridge member such that said lifting force is initially insufficient to pivot said bridge member upwardly from said lowered positon and becomes sufficient to pivot said bridge member automatically to said retracted position when, through external forces, said bridge member is pivoted upwardly and reaches said intermediate position.

In a dock lift having a base and a loading platform which can be raised and lowered with respect to said base, the improvement comprising a retractable throw-over bridge system for joining the loading platform to an adjacent loading surface such as a truck bed or the like, said bridge system comprising:

• an elongate bridge member of a predetermined weight joined at a pivot point to one end of said loading platform and being pivotal between an upright retracted position through an intermediate position above the horizontal and a lowered position below horizontal, and having a selected length so that said bridge member will span a selected space between the loading platform and an adjacent loading surface;
• a bridge retractor assembly joining said bridge member to said platform, said retractor assembly including biasing means for applying a lifting force to said bridge member at a selected lifting point to bias said bridge member upwardly toward said upright retracted position;
• said lifting force of said biasing menas being of a value in relation to the weight of said bridge member such that said lifting force is initially insufficient to pivot said bridge member upwardly from said lowered position and becomes sufficient to pivot said bridge member automatically to said retracted position when, through external forces, said bridge member is pivoted upwardly and reaches said intermediate position.

In a dock lift having a base and a loading platform which can be raised and lowered with respect to said base, the improvement comprising a retractable throw-over bridge system for joining the loading platform to an adjacent loading surface such as a truck bed or the like, said bridge system comprising:

• an elongate bridge member of a predetermined weight joined at a pivot point adjacent one end thereof to one end of said loading platform and being pivotal between an upright retracted position through an intermediate position and a lowered position, and having a selected length so that said bridge member will span a selected space between the loading platform and an adjacent loading surface;
• a bridge retractor assembly joining said bridge member to said platform, said retractor assembly including biasing means for applying an upward lifting force to said bridge member at a selected lifting point spaced outwardly of said pivot point to bias the bridge member upwardly toward said upright retracted position;
• said lifting force of said biasing means being directed along a line constantly located above said pivot point at said one end of said bridge member when the bridge member is in any of said positions, and said lifting force being of a value in relation to the weight of said bridge member such that said lifting force is initially insufficient to pivot said bridge member upwardly from said lowered position and becomes sufficient to pivot said bridge member automatically to said retracted position when, through external forces, said bridge member is pivoted upwardly and reaches said intermediate position.