Slide valve for high-viscosity pumps

Claim 2

A slide valve for a conduit, comprising: a slidable valve element in said conduit displaceable into and out of a position blocking same; a rod connected to said element and passing out through a wall of said conduit; a piston on said rod external of said conduit; a seal in the wall of said conduit tightly surrounding said rod; a fluid cylinder exterNal of said conduit surrounding said rod and receiving said piston, said piston subdividing said cylinder into a flushing compartment between said piston and said seal and an actuating compartment on the other side of said piston; a reservoir containing a flushing fluid; and duct means connecting said reservoir to said flushing compartment for drawing said fluid into said flushing compartment upon displacement of said element in one direction and for expelling said fluid from said flushing compartment on displacement of said element in the other direction, said cylinder being of regular cross-sectional area, the crosssectional area of said piston being greater than that of said rod, said flushing compartment being annular and surrounding said rod, said rod comprising an inner rod member and an outer replaceable and removable sleeve member, said valve element being formed with at least one tube portion having a throughgoing bore fitting said inner rod member, said valve having one such cylinder at each end of said rod, said sleeve members extending fully between said tube portion and said pistons and being clamped in place by same.

Claim 3

The valve defined in claim 1 wherein said cylinder includes a blind tube having a closed end forming said actuating compartment and an open end directed toward said seal.

Claim 4

The valve defined in claim 2, further comprising a clamp nut threadedly engaging said conduit around said seal and having an internal flange, said conduit having an external flange entrained by said nut in the direction of said conduit.

Claim 5

The valve defined in claim 3, further comprising a thrust ring between said open end of said tube and said seal, whereby rotation of said nut compresses and tightens said seal.

Claim 6

The valve defined in claim 1, further comprising a pair of replaceable and removable guide members flanking and slidably receiving said valve element.

Claim 7

The valve defined in claim 1 wherein said reservoir is at least partially transparent.

Claim 8

A slide valve for a conduit comprising: a slidable valve element in said conduit displaceable into and out of a position blocking same; a rod connected to said element and passing out through a wall of said conduit; a piston on said rod external of said conduit; a seal in the wall of said conduit tightly surrounding said rod; a fluid cylinder external of said conduit surrounding said rod and receiving said piston, said piston subdividing said cylinder into a flushing compartment between said piston and said seal and an actuating compartment on the other side of said piston; a reservoir containing a flushing fluid; duct means connecting said reservoir to said flushing compartment for drawing said fluid into said flushing compartment upon displacement of said element in one direction and for expelling said fluid from said flushing compartment on displacement of said element in the other direction; said cylinder being of regular cross-sectional area, the cross-sectional area of said piston being greater than that of said rod, said flushing compartment being annular and surrounding said rod; a pair of replaceable and removable guide members flanking and slidably receiving said valve element; and at least two end-stop members engageable with said element at the limit of travel thereof, said guide members each being formed with matching substantially semicylindrical grooves and said stop members being formed with throughgoing holes, said grooves and said holes forming a throughgoing bore of regular diameter snugly slidably receiving said rod.

Claim 9

A slide valve for a conduit comprising: a slidable valve element in said conduit displaceable into and out of a position blocking same; a rod connected to said element and passing out through a wall of said conduit; a piston on said rod external of said conduit; a seal in the wall of said conduit tightly surrounding said rod; a fluid cylinder external of said conduit surrounding said rod and receiving said piston, said piston subdividing said cylinder into a flushing compartment between said piston and said seal and an actuating compartment on the other side of said piston; a reservoir containing a flushing fluid; duct means connecting said reservoir to said flushing compartment for drawing said fluid into said flushing compartment upon displacement of said element in one direction and for expelling said fluid from said flushing compartment on displacement of said element in the other direction; said cylinder being of regular cross-sectional area, the cross-sectional area of said piston being greater than that of said rod, said flushing compartment being annular and surrounding said rod; a pair of replaceable and removable guide members flanking and slidably receiving said valve element; and at least two end-stop members engageable with said element at the limit of travel thereof, said guide members each being formed with matching substantially semicylindrical grooves and said stop members being formed with throughgoing holes, said grooves and said holes forming a throughgoing bore of regular diameter snugly slidably receiving said rod.

Claim 10

The valve defined in claim 7 wherein said rod comprises an inner rod member and an outer replaceable and removable sleeve member.

Claim 11

The valve defined in claim 8 wherein said valve element is formed with at least one tube portion having a throughgoing bore fitting said inner rod member.

Claim 12

The valve defined in claim 7 wherein said valve element is connected to a pair of such rodS.

Claim 13

A slide valve for a conduit comprising: a slidable valve element in said conduit displaceable into and out of a position blocking same; a rod connected to said element and passing out through a wall of said conduit; a piston on said rod external of said conduit; a seal in the wall of said conduit tightly surrounding said rod; a fluid cylinder external of said conduit surrounding said rod and receiving said piston, said piston subdividing said cylinder into a flushing compartment between said piston and said seal and an actuating compartment on the other side of said piston; a reservoir containing a flushing fluid; duct means connecting said reservoir to said flushing compartment for drawing said fluid into said flushing compartment upon displacement of said element in one direction and for expelling said fluid from said flushing compartment on displacement of said element in the other direction; a pair of substantially flat replaceable and removable guide members flanking and slidably receiving said element, said guide members being formed with opposing substantially semicylindrical grooves; a pair of end-stop members engageable with said element at the extreme limit of travel thereof, said stop members being formed with throughgoing holes, said holes and said grooves defining an axially extending straight bore snugly fitting said rod, said rod having one such cylinder at each end and including an inner rod member carrying at each of its ends one such piston and a sleeve member extending between each of said pistons and said element, said element being formed with tube portion clamped between said sleeve members and having a bore receiving said rod member; a nut having an internal flange and threadedly engaging said conduit around said seal, said cylinder being a blind tube having a closed end forming said actuating compartment and an open end directed toward said seal and formed with an external flange and an internal shoulder, said internal flange bearing on said external flange; and a thrust sleeve between said internal shoulder and said seal whereby rotation of said nut tightens said seal, said reservoir being at least partially transparent, said guide and end-stop members forming a substantially circular opening corresponding to the internal diameter of said conduit and in line therewith, said flushing compartment being annular and surrounding said rod between said seal and said piston.

Claim 14

A slide valve for a conduit comprising: a slidable valve element in said conduit displaceable into and out of a position blocking same; a rod connected to said element and passing out through a wall of said conduit; a piston on said rod external of said conduit; a seal in the wall of said conduit tightly surrounding said rod; a fluid cylinder external of said conduit surrounding said rod and receiving said piston, said piston subdividing said cylinder into a flushing compartment between said piston and said seal and an actuating compartment on the other side of said piston; a reservoir containing a flushing fluid; duct means connecting said reservoir to said flushing compartment for drawing said fluid into said flushing compartment upon displacement of said element in one direction and for expelling said fluid from said flushing compartment on displacement of said element in the other direction; a pair of substantially flat replaceable and removable guide members flanking and slidably receiving said element, said guide members being formed with opposing substantially semicylindrical grooves; a pair of end-stop members engageable with said element at the extreme limit of travel thereof, said stop members being formed with throughgoing holes, said holes and said grooves defining an axially extending straight bore snugly fitting said rod, said rod having one such cylinder at each end and including an inner rod member carrying at each of its ends one such piston and a sleeve member extending between each of said pistons and said element, said element being formed with tube portion clamped between said sleeve members and having a bore receiving said rod member; a nut having an internal flange and threadedly engaging said conduit around said seal, said cylinder being a blind tube having a closed end forming said actuating compartment and an open end directed toward said seal and formed with an external flange and an internal shoulder, said internal flange bearing on said external flange; and a thrust sleeve between said internal shoulder and said seal whereby rotation of said nut tightens said seal, said reservoir being at least partially transparent, said guide and end-stop members forming a substantially circular opening corresponding to the internal diameter of said conduit and in line therewith, said flushing compartment being annular and surrounding said rod between said seal and said piston.

Claim 15

A slide valve for a conduit comprising: a slidable valve element in said conduit displaceable into and out of a position blocking same; a rod connected to said element and passing out through a wall of said conduit; a piston on said rod external of said conduit; a seal in the wall of said conduit tightly surrounding said rod and provided with means for tightening the seal upon wear thereof; a fluid cylinder external of said conduit surrounding said rod and receiving said piston, said piston subdividing said cylinder into a flushing compartment between said piston and said seal and an actuating compartment on the other side of said piston; a reservoir containing a flushing fluid; and a flushing duct connecting said reservoir to said flushing compartment for drawing said fluid into said flushing compartment upon displacement of said element in one direction and for expelling said fluid from said flushing compartment on displacement of said element in the other direction.

Claim 16

A slide valve for a conduit comprising: a slidable valve element in said conduit displaceable into and out of a position blocking same; a rod connected to said element and passing out through a wall of said conduit; a piston on said rod external of said conduit; a seal in the wall of said conduit tightly surrounding said rod and provided with means for tightening the seal upon wear thereof; a fluid cylinder external of said conduit surrounding said rod and receiving said piston, said piston subdividing said cylinder into a flushing compartment between said piston and said seal and an actuating compartment on the other side of said piston; a reservoir containing a flushing fluid; and a flushing duct connecting said reservoir to said flushing compartment for drawing said fluid into said flushing compartment upon displacement of said element in one direction and for expelling said fluid from said flushing compartment on displacement of said element in the other direction.

Claim 17

The slide valve defined in claim 12 wherein said valve element is provided with a respective rod on opposite sides thereof and extending in the direction of displacement of said valve element, each of said rods being provided with a respective piston, seal, fluid cylinder and flushing duct as defined.