Means for maintaining spacing in a continuous press

Claim 2

In a press having two press platens, each of which is supported on an external support construction wherein the force from one press platen is transmitted to its corresponding support construction through a pressure fluid within a pressure element positioned between the platen and its corresponding support construction, apparatus for maintaining constant spacing between the two press platens comprising: a. means rigidly coupliNg the support constructions associated with each of said two press platens; b. means for sensing deviations of one press platen from a predetermined position and for regulating the pressure elements so as to maintain said one press platen at said predetermined position during a pressing operation so as to maintain said predetermined position throughout the pressing operation.

Claim 3

Apparatus according to claim 1 in which said means for sensing and maintaining comprises a guide valve comprising: a. a first element coupled to said one press platen; b. a second element movable with respect to said first element and coupled to the support construction associated with said one press platen; c. an inlet port in said valve; d. a first outlet port in said valve coupled to said pressure element and in communication with said inlet port; e. a second outlet port in said valve coupled to a reservoir; and f. means responsive to relative movement of said two elements corresponding to movement from said predetermined position to couple said inlet with said second outlet.

Claim 4

Apparatus according to claim 2 wherein said guide valve is a longitudinal sliding valve which operates parallel to the direction of motion of said one pressure platen, said valve comprising: a a valve housing; b a slide having a sealing surface on its leading edge slidably mounted within said valve housing; c a counter surface within said valve housing which cooperates with said sealing surface to form a seal when said slide and said counter surface are abutting; d an inlet formed in said valve housing; e a first outlet formed in said valve housing in communication with said inlet; f a second outlet in said valve housing; g a channel formed in said valve housing, said channel being in communication with said inlet and said counter surface, whereby said inlet will be sealed from said second outlet as long as the seal between said sealing surface and said counter surface is maintained.

Claim 5

Apparatus according to claim 3 wherein said counter surface is contained on the end of a counter slide slidably mounted within said housing and further including a threaded spindle engaging threads in said housing and in contact with said counter slide whereby the axial position of said counter slide may be adjusted.

Claim 6

Apparatus according to claim 4 wherein a plurality of guide valves are provided and further including means to jointly drive the spindles of each of said plurality of guide valves.