Device for changing pitch of stack

Abstract

The purpose of the invention is to efficiently perform the work of changing stacked objects, which are stacked in one container with one pitch, to another pitch and storing same in the stacked form in another container. Multiple workpieces ( 51 ) are juxtaposed in a stacked form with a prescribed pitch and attachment pads ( 25 ) for attaching the workpieces are provided on base plates ( 3 ). The pitch between the base plates can be varied by rotating variable spacers ( 17 ), which work in concert with a drive shaft ( 31 ). An airtight communicating channel ( 28 ), which communicates with the attachment pads, is formed within a group of base plates. The communicating channel ( 28 ) is formed by the consecutive installation of an expandable elastic packing ( 15 ) between the through holes of adjacent base plates. The elastic packing and the variable spacers move in concert with the base plates. The base plates are provided with springs ( 9 ) for releasing the fixing of an inter-base plate pitch. Areas of differing thickness are formed on the circumferential surface of the variable spaces ( 17 ).

1 . A device for changing a pitch of a plurality of thin works juxtaposed in a stacked form with a predetermined pitch between adjacent ones,
 characterized in that;   it comprises a movable holder unit and a drive unit for driving the movable holder unit;   the movable holder unit comprises a plurality of base plates juxtaposed in a stacked form with a predetermined pitch,   each of said base plates includes operating member(s) that support the work, the operating member(s) being driven by drive power supplied from communicating channel(s) to hold the work individually;   each of said base plates includes rotatable variable spacer(s) interlocking with a drive shaft of the drive unit, and the pitch between the base plates becomes variable by rotation of the variable spacer(s); and   when the work is held by each of said base plate, the airtight, expandable communicating channel(s) is formed between the base plates in communication with the operating member.   
     
     
         2 . The stack pitch changing device according to  claim 1 , wherein the communicating channel is formed by expandable elastic packings mounted in series between through holes of the adjacent base plates. 
     
     
         3 . The stack pitch changing device according to  claim 2 , wherein each of said elastic packing is moved along with each of said base plate. 
     
     
         4 . The stack pitch changing device according to  claim 1 , wherein each of said variable spacer is moved along with each of said base plate. 
     
     
         5 . It is further characterized in that, in the stack pitch changing device according to  claim 1 , wherein each of said base plate is provided with spring(s) for releasing the fixed pitch between the base plates. 
     
     
         6 . The stack pitch changing device according to  claim 2 , wherein the elastic packing is formed like bellows. 
     
     
         7 . The stack pitch changing device according to  claim 1 , wherein the variable spacer has different parts having different thickness formed on its circumferential surface, and the pitch between the base plates may be changed by rotating the variable spacer so that the base plate becomes in contact with another part of different thickness. 
     
     
         8 . The stack pitch changing device according to  claim 5 , wherein the spring at a side of a stationary base plate has a spring force for restoring the contracted base plate, which is greater than a spring force of the spring at a side of a movable base plate. 
     
     
         9 . The stack pitch changing device according to  claim 8 , wherein the spring forces are made smaller stepwise toward the movable base plate for every predetermined number of the base plate. 
     
     
         10 . The stack pitch changing device according to  claim 8 , wherein the spring forces are made smaller linearly toward the movable base plate. 
     
     
         11 . The stack pitch changing device according to  claim 5 , wherein the spring comprises a single spring. 
     
     
         12 . The stack pitch changing device according to  claim 5 , wherein the springs comprise a stack of plural springs. 
     
     
         13 . The stack pitch changing device according to  claim 1 , wherein there is provided a detection unit for detecting the work condition such as crack or damage when absorbing the work. 
     
     
         14 . The stack pitch changing device according to  claim 13 , wherein the detection unit comprises an opening/closing valve mounted at an entrance of the communicating channel for opening and closing the communicating channel, an orifice mounted to the opening/closing valve in communication with a vacuum pressure detection path, and a sensor connected to the vacuum pressure detection path, so that a pressure change in the communicating channel is detected, after the drive power is inputted to the communicating channel and then the opening/closing valve is closed. 
     
     
         15 . The stack pitch changing device according to  claim 1 , wherein the operating member comprises suction pad(s) that absorb the work. 
     
     
         16 . The stack pitch changing device according to  claim 1 , wherein the operating member comprises clamping member(s) that clamp the work. 
     
     
         17 . The stack pitch changing device according to  claim 1 , wherein the base plates are classified into groups, each group comprising a predetermined number of the base plates. 
     
     
         18 . The stack pitch changing device according to  claim 1 , wherein each of said base plates is provided with a pair of the operating members, and each of said base plates is provided with a pair of the communicating channels that communicate with the variable spacers and the operating members. 
     
     
         19 . The stack pitch changing device according to  claim 1 , wherein the operating member(s) support surface(s) of the work extending perpendicularly to a stacking direction. 
     
     
         20 . The stack pitch changing device according to  claim 1 , wherein the operating member(s) support surface(s) of the work extending along a stacking direction. 
     
     
         21 . A suction pad for use in a device for changing a pitch of a stack as means for holding a work, characterized in that airtight, expandable communicating channel(s) is formed between the base plates.