Lift table assembly for a welding press

Claim 2

A lift table forming part of a welding press assembly, comprising a base structure including a floorlike member, a top structure overlying said base structure, link means extending between said base structure and said top structure for effecting vertical movement of the latter relative to said base structure, guide means in part provided by said base structure and in part provided by said top structure for guiding movement of the latter, upstanding wall means forming a part of said base structure and enclosing said guide means and said link means, said link means comprising a plurality of links pivotally secured to and depending from said top structure, the lower portion of each link being pivotally secured to crank means rotatably carried by said base structure, and means carried by said base structure and interconnecting said crank means for unitary rotation.

Claim 3

A lift table forming part of a welding press assembly, comprising a base structure including a floorlike member, a top structure overlying said base structure, link means extending between said base structure and said top structure for effecting vertical movement of the latter relative tO said base structure, guide means in part provided by said base structure and in part provided by said top structure for guiding movement of the latter, upstanding wall means forming a part of said base structure and enclosing said guide means and said link means, said link means comprising a pair of spaced-apart links pivotally secured to and depending from said top structure and respectively disposed adjacent opposed portions of said wall means, and a pair of crank arms each swingable in an arcuate path between a first position wherein each extends upwardly of its rotational axis and a second position wherein each extends downwardly of its rotational axis, the lower portion of each of said links being pivotally secured to a respective crank arm, said crank arms in position intermediate said first and second positions extending toward each other and away from respective wall means portions to maximize the spacings between said link means with minimum spacing between said wall means opposed portions, and means carried by said base structure within said wall means and interconnecting said cranks for unitary movement.

Claim 4

A lift table forming part of a welding press assembly, comprising a base structure including a floorlike member, a top structure overlying said base structure, link means extending between said base structure and said top structure for effecting vertical movement of the latter relative tO said base structure, guide means in part provided by said base structure and in part provided by said top structure for guiding movement of the latter, upstanding wall means forming a part of said base structure and enclosing said guide means and said link means, said link means comprising a pair of spaced-apart links pivotally secured to and depending from said top structure and respectively disposed adjacent opposed portions of said wall means, and a pair of crank arms each swingable in an arcuate path between a first position wherein each extends upwardly of its rotational axis and a second position wherein each extends downwardly of its rotational axis, the lower portion of each of said links being pivotally secured to a respective crank arm, said crank arms in position intermediate said first and second positions extending toward each other and away from respective wall means portions to maximize the spacings between said link means with minimum spacing between said wall means opposed portions, and means carried by said base structure within said wall means and interconnecting said cranks for unitary movement.

Claim 5

The construction of claim 1 wherein said base structure is four-sided in plan, and wherein a link aforesaid is provided adjacent each base structure corner.

Claim 6

The construction of claim 3 wherein said links are arranged in pairs, wherein the links of one link pair are connected to crank means within said wall means rotatable about one axis and the links of the other link pair are connected to crank means within said wall means rotatable about another axis spaced laterally of said one axis, and wherein means within said wall means interconnects said crank means for unitary rotation about respective axes.

Claim 7

The construction of claim 4 wherein said crank means axes are provided by respective shafts, wherein a pair of gear segments within said wall means have driving engagement with respective shafts, wherein said gear segments are connected to respective eccentric journals by respective pitmans within said wall means, wherein said eccentric journals are rotatable in unison about a drive axis disposed between said shaft axes, and wherein a drive motor is mounted on said base structure and effects rotation of said eccentric journals about said drive axis.

Claim 8

The construction of claim 1 wherein said crank means provides a crankpin offset radially of an axis and movable in an arcuate path thereabout, wherein said links have pivotal connection with said top structure, wherein said crankpin is eccentrically mounted to provide for shifting its radial position relative to the axis about which it is movable to thereby vary the distance through which said top structure is reciprocated, and wherein each link pivotal connection comprises a pivot pin selectively positionable through apertures closely receiving the same and spaced apart an amount equal to the radial shift in position of said crank pin whereby said top structure predetermined position is unaffected by the aforesaid shift in radial position of said crankpin.

Claim 9

In a welding press having a platen reciprocable toward and away from a fixed platen, said platens being adapted to carry cooperating parts of a welding fixture whereby said movable platen is required to have a predetermined spaced relation with respect to said fixed platen at the end of its stroke toward the latter, the improvement comprising; a crank arm having one end connected to a rotatable shaft which is disposed transverse to the line of stroke of said movable platen whereby its opposite end is movable in a circular path about the axis of said shaft, a crankpin fixed to a pivot pin at said other end of said crank arm, said crankpin being offset radially of the axis of said pivot pin, link means having one end pivotally connected to said crankpin and its opposite end pivotally connected to said movable platen for translating circular moveMent of said crank arm to reciprocatory movement of said movable platen, said crankpin being adjustable to various positions radially of said pivot pin axis to thereby vary the distance between it and the crank arm shaft and thus vary the stroke of said movable platen, and means for adjusting the pivotal connection between said movable platen and said link means in a direction toward and away from said movable platen an amount corresponding and equal to the adjustment in the radial position of said crankpin whereby said predetermined spaced relation between said fixed and movable platens is unaffected by the radial adjustment of said crankpin.

Claim 10

In a welding press having a platen reciprocable toward and away from a fixed platen, said platens being adapted to carry cooperating parts of a welding fixture whereby said movable platen is required to have a predetermined spaced relation with respect to said fixed platen at the end of its stroke toward the latter, the improvement comprising; a crank arm having one end connected to a rotatable shaft which is disposed transverse to the line of stroke of said movable platen whereby its opposite end is movable in a circular path about the axis of said shaft, a crankpin fixed to a pivot pin at said other end of said crank arm, said crankpin being offset radially of the axis of said pivot pin, link means having one end pivotally connected to said crankpin and its opposite end pivotally connected to said movable platen for translating circular moveMent of said crank arm to reciprocatory movement of said movable platen, said crankpin being adjustable to various positions radially of said pivot pin axis to thereby vary the distance between it and the crank arm shaft and thus vary the stroke of said movable platen, and means for adjusting the pivotal connection between said movable platen and said link means in a direction toward and away from said movable platen an amount corresponding and equal to the adjustment in the radial position of said crankpin whereby said predetermined spaced relation between said fixed and movable platens is unaffected by the radial adjustment of said crankpin.

Claim 11

The construction according to claim 7 wherein the pivotal connection between said link means and said movable platen comprises an ear depending from the latter and having a pair of openings, one closer to said fixed platen than the other, and a pivot pin on said link means and disposed within a selected one of said pair of openings.