Loading rigid sheet materials

Claim 2

Apparatus for assisting the loading of a rigid sheet into substantially simultaneous gripping engagement with a plurality of freely suspended self-closing tongs spaced apart along a given surface comprising tong pivotal motion limiting means adapted for positioning sufficiently close to the position occupied by each of said self-closing tongs when the latter are freely suspended and constructed and arranged to simultaneously limit the amount of pivotal movement of each of said freely suspended tongs in directions having components both normal to and parallel to said given surface and movement guide means associated with the tong pivotal motion limiting means to guide the movement of an upper portion of the rigid sheet in an upward direction along said given surface and arranged such that upward movement of the rigid sheet along said movement guide means brings said upper sheet portion into contact with the self-closing tongs to cause the tongs to open and reCeive said upper sheet portion, whereby said tongs remain in proper location or orientation relative to the rigid sheet and thereafter close to substantially simultaneously grip and support the sheet when a force on the sheet causing said upward movement is relieved.

Claim 3

Apparatus for handling rigid sheet material comprising a carriage movable along a path of travel, a plurality of self-closing tongs, and linkages freely suspending said tongs from said carriage, said tongs being in spaced apart relation along a given surface, tong pivotal motion limiting means adapted for positioning sufficiently close to the position occupied by each of said self-closing freely suspended tongs and constructed and arranged to simultaneously limit the amount of pivotal movement of each of said freely suspended tongs in directions having components both normal to and parallel to said given surface and movement guide means associated with the tong pivotal motion limiting means to guide the movement of an upper portion of the rigid sheet in an upward direction along said given surface and arranged such that upward movement of the rigid sheet along said movement guide means brings said upper sheet portion into contact with the self-closing tongs to cause the tongs to open and receive said upper sheet portion, whereby said tongs remain in proper location or orientation relative to the rigid sheet and thereafter close to substantially simultaneously grip and support the sheet when a force on the sheet causing said upward movement is relieved.

Claim 4

Apparatus for handling rigid sheet material comprising a carriage movable along a path of travel, a plurality of self-closing tongs, and linkages freely suspending said tongs from said carriage, said tongs being in spaced apart relation along a given surface, tong pivotal motion limiting means adapted for positioning sufficiently close to the position occupied by each of said self-closing freely suspended tongs and constructed and arranged to simultaneously limit the amount of pivotal movement of each of said freely suspended tongs in directions having components both normal to and parallel to said given surface and movement guide means associated with the tong pivotal motion limiting means to guide the movement of an upper portion of the rigid sheet in an upward direction along said given surface and arranged such that upward movement of the rigid sheet along said movement guide means brings said upper sheet portion into contact with the self-closing tongs to cause the tongs to open and receive said upper sheet portion, whereby said tongs remain in proper location or orientation relative to the rigid sheet and thereafter close to substantially simultaneously grip and support the sheet when a force on the sheet causing said upward movement is relieved.

Claim 5

Apparatus according to claim 1 wherein sheet end portion engaging guide means are provided for engagement with an end portion of the sheet as it is moved in said upward direction whereby to ensure that the sheet is loaded in its correct horizontal position relative to the vertical center line of the carriage.

Claim 6

Apparatus according to claim 2 wherein sheet end portion engaging guide means are provided for engagement with an end portion of the sheet as it is moved in said upward direction whereby to ensure that the sheet is loaded in its correct horizontal position relative to the vertical center line of the carriage.

Claim 7

Apparatus according to claim 2 further including motion producing means for advancing and retracting said tong pivotal motion limiting means and said movement guide means towards and away from said carriage and the tongs suspended therefrom.

Claim 8

Apparatus according to claim 1 wherein said tong pivotal motion limiting means for limiting the pivotal movement of the tongs comprises a member having a number of recesses therein, the number of recesses being at least equal to the number of tongs, each recess arranged to receive a portion of a respective one of said tongs and being sized to effect said limiting of the pivotal movement of the tongs, and a surface portion of said member defining said movement guide means along which said upper sheet portion is moved.

Claim 9

Apparatus according to claim 2 wherein said tong pivotal motion limiting means for limiting the pivotal movement of the tongs comprises a member having a number of recesses therein, the number of recesses being at least equal to the number of tongs, each recess arranged to receive a portion of a respective one of said tongs and being sized to effect said limiting of the pivotal movement of the tongs, and a surface portion of said member defining said movement guide means along which said upper sheet portion is moved.

Claim 10

Apparatus according to claim 1 further including motion producing means for advancing and retracting said tong pivotal motion limiting means and said movement guide means towards and away from said carriage and the tongs suspended therefrom.