Prestressed press

Claim 2

In a prestressed press including a bed member, a crown member and a ram carried by one of said members for performing a work function between the ram and the other of said members, the improvement comprising, a plurality of downwardly facing saddles on the bed member, a plurality of upwardly facing saddles on the crown member, a plurality of tension members extending between and along the sides of the bed member and crown member beyond the saddles thereon and having offsets therein respectively engaging the downwardly facing saddles on the bed member and the upwardly facing saddles on the crown member, a plurality of compression members interposed between the bed member and the crown member, and shim means between the plurality of compression members and at least one of said bed and crown members for maintaining tension in said plurality of tension members and compression in said plurality of compression members.

Claim 3

A prestressed press as defined in claim 1 wherein said shim means comprise wedge blocks which are driven into place.

Claim 4

A prestressed press as defined in claim 2 wherein said downwardly and upwardly facing saddles are substantially cylindrically convex and said offsets in the plurality of tension members which engage the saddles are substantially cylindrically concave, whereby stress concentrations are reduced to a minimum.

Claim 5

A prestressed press as defined in claim 1 wherein said downwardly and upwardly facing saddles are substantially cylindrically convex and said offsets in the plurality of tension members which engage the saddles are substantially cylindrically concave, whereby stress concentrations are reduced to a minimum.

Claim 6

A prestressed press as defined in claim 4 comprising means for clamping together the lower ends of the plurality of tension members adjacent the bed member and means for clamping together the upper ends of the plurality of tension members adjacent the crown member to counteract the moments of forces in the plurality of tension members about the offsets therein which engage the saddles.

Claim 7

A prestressed press as defined in claim 5 wherein said clamping means comprise tension rods extending respectively between the upper ends and the lower ends of the plurality of tension members.

Claim 8

A prestressed press as defined in claim 5 where said clamping means comprise outwardly facing shoulders on the ends of the plurality of tension members, plates overlying the upper ends of the plurality of tension members and having inwardly facing shoulders adjacent the outwardly facing shoulders on the tension members, and shim means interposed between thE shoulders on the tension members and on the plates.

Claim 9

A prestressed press as defined in claim 7 including bolts extending through the plates into the plurality of tension members outwardly beyond the shoulders thereon to secure the plates to the tension members.

Claim 10

A prestressed press as defined in claim 1 comprising means for clamping together the lower ends of the plurality of tension members adjacent the bed member and means for clamping together the upper ends of the plurality of tension members adjacent the crown member to counteract the moments of forces in the plurality of tension members about the offsets therein which engage the saddles.

Claim 11

A prestressed press as defined in claim 9 wherein said clamping means comprise tension rods extending respectively between the upper ends and the lower ends of the plurality of tension members.

Claim 12

A prestressed press as defined in claim 9 wherein said clamping means comprise outwardly facing shoulders on the ends of the plurality of tension members, plates overlying the upper ends of the plurality of tension members and having inwardly facing shoulders adjacent the outwardly facing shoulders on the tension members, and shim means interposed between the shoulders on the tension members and on the plates .

Claim 13

A prestressed press as defined in claim 11 including bolts extending through the plates into the plurality of tension members outwardly beyond the shoulders thereon to secure the plates to the tension members.

Claim 14

A prestressed press as defined in claim 1 wherein said ram is hydraulically operated, and wherein movement of said ram is blocked against said other of said members while hydraulic pressure above the rated capacity is applied to said ram for initially tensioning said plurality of tension members.

Claim 17

A prestressed press including a bed member, a crown member and a ram carried by one of said members for performing a work function between the ram and the other of said members, a plurality of downwardly facing saddles on the bed member, a plurality of upwardly facing saddles on the crown member, a plurality of tension members extending between and along the sides of the bed member and crown member beyond the saddles thereon and having offsets therein respectively engaging the downwardly facing saddles on the bed member and the upwardly facing saddles on the crown member, a plurality of compression members interposed between the bed member and the crown member, and shim means between the plurality of compression members and at least one of said bed and crown members for maintaining tension in said plurality of tension members and compression in said plurality of compression membErs, the tensioning of said tension members and the compressing of said compression members and, hence, the prestressing of the press resulting from blocking the ram against said other of said bed and crown members, applying pressure above the rated capacity of the press to stretch and initially tension the plurality of tension members, manipulating the shim means to take up for the stretched condition of the plurality of tension members, and removing said applied pressure and the blocking between the ram and said other of said members.

Claim 18

A prestressed press including a bed member, a crown member and a ram carried by one of said members for performing a work function between the ram and the other of said members, a plurality of downwardly facing saddles on the bed member, a plurality of upwardly facing saddles on the crown member, a plurality of tension members extending between and along the sides of the bed member and crown member beyond the saddles thereon and having offsets therein respectively engaging the downwardly facing saddles on the bed member and the upwardly facing saddles on the crown member, a plurality of compression members interposed between the bed member and the crown member, and shim means between the plurality of compression members and at least one of said bed and crown members for maintaining tension in said plurality of tension members and compression in said plurality of compression membErs, the tensioning of said tension members and the compressing of said compression members and, hence, the prestressing of the press resulting from blocking the ram against said other of said bed and crown members, applying pressure above the rated capacity of the press to stretch and initially tension the plurality of tension members, manipulating the shim means to take up for the stretched condition of the plurality of tension members, and removing said applied pressure and the blocking between the ram and said other of said members.