Toggle-joint press

Claim 2

A fluid-driven toggle-joint press of the type comprising a cylinder having a control piston means moveable therein which is joined by a connecting rod to the knee of a toggle joint formed by at least two links, one link being hinged at a fixed point and the other at the end of a tool-holding piston, the press being characterized by the improvement comprising: said control piston means being formed of two relatively moveable coaxial pistons; and means for stopping and thus limiting the travel of at least one of said coaxial piston while permitting the other to continue its motion to effect the return of the tool-holding piston.

Claim 3

A toggle-joint press as set forth in claim 1, further comprising adjustment means for varying the high point of said tool-holding piston in a return position thereof.

Claim 4

A toggle-joint press as set forth in claim 1, wherein said coaxial pistons are moveable one within a bore formed in the other and said stopping and travel limiting means comprises shoulder means formed in the bore of the other piston dividing said bore into two airtight chambers.

Claim 5

A toggle-joint press as set forth in claim 3, wherein said coaxial pistons are moveable one within a bore formed in the other and said outer piston comprises spaced apart and joined piston heads slidable in said cylinder and said inner piston comprises spaced apart piston heads slidable in said bore and connected by respective rods to a common toggle joint.

Claim 6

A toggle-joint press as set forth in cllaim 3, wherein said one piston moveable in the other includes a piston rod slidable in the means forming said shoulder and two piston heads at opposite ends of said piston rod being disposed respectively in said two chambers.

Claim 7

A toggle-joint press as set forth in cllaim 3, wherein said one piston moveable in the other includes a piston rod slidable in the means forming said shoulder and two piston heads at opposite ends of said piston rod being disposed respectively in said two chambers.

Claim 8

A toggle-joint press as set forth in claim 5, wherein said inner piston is joined to said knee of said toggle joint.

Claim 9

A toggle-joint press comprising: a base; a housing supported on said base; a tool-holding piston being moveable along a given line in said housing between an operative and a return position; a cyliNder in said housing; a first piston moveably disposed axially in said cylinder and having an elongate axial opening formed therein, and means in said opening to define a pair of oppositely facing stops; control means for supplying pressurized fluid to said cylinder selectively to the ends thereof for causing said first piston to move axially therein; a second piston moveably disposed axially in said opening and having a pair of piston heads at the ends thereof, a first one of said piston heads being engageable by a first one of said stops for causing said second piston to move simultaneously with said first piston when said first piston moves in one direction and for limiting the travel of said second piston in the other direction independently of said first piston, and the second one of said piston heads being engageable by the second one of said stops for causing said second piston to move simultaneously with said first piston when said first piston moves in the other direction and for limiting the travel of said second piston in said one direction independently of said first piston, said second piston thereby having a longer path of linear translation than said first piston; conduit means connecting said cylinder on opposite sides of said first piston moveable therein to said opening in said first piston; a toggle-joint composed of two links connected at one end thereof in a knee joint, with the other end of one link being hingedly fixed within said housing and the other end of the other link being hingedly connected to one end of said tool-holding piston; and at least one connecting rod being hingedly connected at one end to said knee joint and at its other end to one of said piston heads of said second piston; whereby upon movement of said first piston to its limit of travel in said one direction, said second piston moving therewith through the engagement of said first stop with said first piston head, said tool-holding piston is moved to said operative position and said pressurized fluid then passes through said conduit means in said first piston to further move said second piston in said one direction independently of said first piston to cause said tool-holding piston to be moved to said return position, and upon movement of said first piston to its limit of travel in said other direction, said second piston moving therewith through the engagement of said second stop with said second piston head, said tool-holding piston is moved to its operative position and said pressurized fluid then passes through said conduit means in said first piston to further move said second piston in said other direction independently of said first piston to cause said tool-holding piston to be moved to said return position.

Claim 10

A toggle-joint press comprising: a base; a housing supported on said base; a tool-holding piston being moveable along a given line in said housing between an operative and a return position; a cyliNder in said housing; a first piston moveably disposed axially in said cylinder and having an elongate axial opening formed therein, and means in said opening to define a pair of oppositely facing stops; control means for supplying pressurized fluid to said cylinder selectively to the ends thereof for causing said first piston to move axially therein; a second piston moveably disposed axially in said opening and having a pair of piston heads at the ends thereof, a first one of said piston heads being engageable by a first one of said stops for causing said second piston to move simultaneously with said first piston when said first piston moves in one direction and for limiting the travel of said second piston in the other direction independently of said first piston, and the second one of said piston heads being engageable by the second one of said stops for causing said second piston to move simultaneously with said first piston when said first piston moves in the other direction and for limiting the travel of said second piston in said one direction independently of said first piston, said second piston thereby having a longer path of linear translation than said first piston; conduit means connecting said cylinder on opposite sides of said first piston moveable therein to said opening in said first piston; a toggle-joint composed of two links connected at one end thereof in a knee joint, with the other end of one link being hingedly fixed within said housing and the other end of the other link being hingedly connected to one end of said tool-holding piston; and at least one connecting rod being hingedly connected at one end to said knee joint and at its other end to one of said piston heads of said second piston; whereby upon movement of said first piston to its limit of travel in said one direction, said second piston moving therewith through the engagement of said first stop with said first piston head, said tool-holding piston is moved to said operative position and said pressurized fluid then passes through said conduit means in said first piston to further move said second piston in said one direction independently of said first piston to cause said tool-holding piston to be moved to said return position, and upon movement of said first piston to its limit of travel in said other direction, said second piston moving therewith through the engagement of said second stop with said second piston head, said tool-holding piston is moved to its operative position and said pressurized fluid then passes through said conduit means in said first piston to further move said second piston in said other direction independently of said first piston to cause said tool-holding piston to be moved to said return position.

Claim 11

A toggle-joint press as set forth in claim 7, wherein said stops are formed by an internal annular shoulder formed in said axial opening.

Claim 12

A toggle-joint press as set forth in claim 7, wherein said first piston comprises a pair of opposed coaxially disposed piston heads having respective hollow piston rods facing each other forming said axial opening for said piston heads of said second piston, said stops being defined by the inside axial ends of said hollow piston rods, and each of said piston heads of said second piston are connected to said toggle joint through hinged connecting rods.

Claim 13

A toggle-joint press as set forth in claim 7, further comprising means for selectively adjusting the return position of said tool-holding piston.