Scissors-type hoist mechanism

Claim 2

A scissors-type hoist mechanism comprising a generally rectangular base support frame adapted to be positioned in a generally horizontal plane, an upright end support frame at one side of said base support frame, a single power driven, vertically disposed, lift screw mounted in said end support frame, a sheet supporting platform assembly disposed for movement in a vertical path above said base support frame, a nut carried on said lifT screw which is driven in a vertical path by rotation of said lift screw, a housing encompassing said nut, said nut housing having laterally extending bearing forming means on oppositely disposed walls, a hook-shaped bracket on said platform assembly which extends at the side adjoining said lift screw, said bracket having a downwardly opening recessed bottom edge adapted to seat on said bearing forming means so as to detachably connect said bracket to said nut housing for movement therewith, a pair of scissors-like arm assemblies connecting said platform assembly and said base support frame for holding said platform assembly in a plane generally parallel with the plane of said base support frame during movement of said platform assembly, said platform assembly having a plurality of sheet supporting rollers thereon and power means carried on said platform assembly for driving said rollers so as to enable sheets thereon to be discharged from said platform assembly.

Claim 3

A scissors-type hoist mechanism adapted for use in supporting a pile of metal sheets which are dropped thereon by an overhead conveyor in a sheet piling machine, said hoist mechanism comprising a generally rectangular base support frame, an upright end support frame at one side of said base support frame, a single power driven, vertically disposed, lift screw mounted in said end support frame, a sheet supporting platform assembly disposed for vertical reciprocating movement above said base support frame, a lift nut carried on said lift screw which is driven by rotation of said lift screw, a hook-shaped bracket on said platform assembly which extends at the side adjoining said lift screw and is detachably connected to said lift nut for movement in a vertical path, said lift nut having a housing secured thereon with laterally extending bearing members, said hook-shaped bracket comprising parallel, spaced, vertically disposed plate members with recesses in their lower edges in which said bearing forming members are seated, a pair of scissors-like arm assemblies connecting said platform assembly and said base support frame for holding said platform assembly in a plane generally parallel with the plane of said base support frame during vertical movement of said platform assembly, said platform assembly having a plurality of sheet supporting rollers thereon and power means for driving said rollers so as to enable sheets thereon to be discharged from said platform assembly in a direction laterally of said end support frame.

Claim 4

A scissors-type hoist mechanism adapted for use in supporting a pile of metal sheets which are dropped thereon by an overhead conveyor in a sheet piling machine, said hoist mechanism comprising a generally rectangular base support frame, an upright end support frame at one side of said base support frame, a single power driven, vertically disposed, lift screw mounted in said end support frame, a sheet supporting platform assembly disposed for vertical reciprocating movement above said base support frame, a lift nut carried on said lift screw which is driven by rotation of said lift screw, a hook-shaped bracket on said platform assembly which extends at the side adjoining said lift screw and is detachably connected to said lift nut for movement in a vertical path, said lift nut having a housing secured thereon with laterally extending bearing members, said hook-shaped bracket comprising parallel, spaced, vertically disposed plate members with recesses in their lower edges in which said bearing forming members are seated, a pair of scissors-like arm assemblies connecting said platform assembly and said base support frame for holding said platform assembly in a plane generally parallel with the plane of said base support frame during vertical movement of said platform assembly, said platform assembly having a plurality of sheet supporting rollers thereon and power means for driving said rollers so as to enable sheets thereon to be discharged from said platform assembly in a direction laterally of said end support frame.

Claim 5

A scissors-type hoist mechanism as set forth in claim 1 wherein said upright support frame has vertically disposed track-forming members adjacent opposite sides of said lift screw housing and said hook-shaped bracket has a carriage forming frame mounted on the extended end thereof with laterally spaced anti-friction means which are positioned to engage and ride on said track forming members so as to hold said platform against twisting movement as it traverses a vertical path.

Claim 6

A scissors-type hoist mechanism as set forth in claim 1 wherein said end support frame includes parallel plate members mounted on opposite sides of said lift screw and having parallel track-forming outer edges extending along said screw, and said hook-shaped bracket comprising parallel end plate members with hook forming outer ends which seat on said bearing forming means and carriage forming means on the ends of said plate members having anti-friction rollers disposed to ride on the track-forming edges of said frame plate members so as to relieve the stress on said lift nut and lift screw resulting from the weight of said platform assembly.

Claim 7

A scissors-type hoist mechanism as set forth in claim 2 and said end support frame having a vertically disposed bumper pad mounted on the inside face thereof adjacent the top end so as to form a stop member for engagement by the leading ends of sheets which have a forward momentum when released from a conveyor for deposit on said platform assembly.

Claim 8

A scissoRs-type hoist mechanism for supporting sheets in a pile thereon which mechanism comprises a generally rectangular, horizontally disposed base support frame, an upright end support frame at one side of said base support frame, a power driven, vertically disposed lift screw mounted in said end support frame, a sheet supporting platform assembly disposed for movement in a vertical path above said base support frame, a nut carried on said lift screw which is driven in a vertical path by rotation of said lift screw, a housing carried on said nut, said nut housing having laterally extending cylindrical bearing members on opposite faces thereof, a hook-shaped bracket on said platform assembly which extends at the side adjoining said lift screw, said hook-shaped bracket having laterally spaced, parallel, side plate members which are recessed on the bottom to fit over said bearing members and detachably connect said bracket to said nut housing for vertical movement therewith, scissors-like arm assemblies disposed in spaced vertical planes and connecting said platform assembly and said base support frame for holding said platform assembly in a plane generally parallel with the plane of said base support frame during vertical movement of said platform assembly, said platform assembly having a plurality of sheet supporting rollers mounted thereon and power means carried on said platform assembly for driving said rollers in a direction to discharge sheets thereon at one side of said platform assembly.

Claim 9

A scissoRs-type hoist mechanism for supporting sheets in a pile thereon which mechanism comprises a generally rectangular, horizontally disposed base support frame, an upright end support frame at one side of said base support frame, a power driven, vertically disposed lift screw mounted in said end support frame, a sheet supporting platform assembly disposed for movement in a vertical path above said base support frame, a nut carried on said lift screw which is driven in a vertical path by rotation of said lift screw, a housing carried on said nut, said nut housing having laterally extending cylindrical bearing members on opposite faces thereof, a hook-shaped bracket on said platform assembly which extends at the side adjoining said lift screw, said hook-shaped bracket having laterally spaced, parallel, side plate members which are recessed on the bottom to fit over said bearing members and detachably connect said bracket to said nut housing for vertical movement therewith, scissors-like arm assemblies disposed in spaced vertical planes and connecting said platform assembly and said base support frame for holding said platform assembly in a plane generally parallel with the plane of said base support frame during vertical movement of said platform assembly, said platform assembly having a plurality of sheet supporting rollers mounted thereon and power means carried on said platform assembly for driving said rollers in a direction to discharge sheets thereon at one side of said platform assembly.

Claim 10

A scissors-type hoist mechanism as set forth in claim 6 wherein said platform assembly includes a stop member disposed at the discharge side of said platform for normally preventing removal of sheets thereon by rotation of said sheet supporting rollers, which stop member comprises an elongate bar member mounted for swinging movement on end pivots, means causing said bar member to swing to a position where the topmost edge normally extends above the plane of the sheet supporting top face of said platform assembly, and wherein a cam forming bracket is provided on said base support frame for biasing said bar member to an inoperative position where the topmost edge is ineffective as a stop member when said platform assembly is disposed in the lowermost position.

Claim 11

A scissors-type hoist as set forth in claim 6 wherein said platform assembly is provided with a stop member comprising an elongate bar which is pivotally mounted at its opposite ends along the discharge side of said platform assembly and said stop bar is balanced on its pivot mounting so that it normally pivots to a position where the top margin projects above the plane of the top face of said platform assembly, and wherein said base support frame has a cam forming member thereon which is disposed to engage said bar when said platform assembly is lowered to a position adjacent said base support frame and pivot the same from its normal operative position to an inoperative position where the top margin is below the plane of the top face of the said platform assembly.