Pumps and painting installations

Claim 2

A high pressure airless paint spraying installation including a suction and delivery pump comprising a pump piston member and a pump cylinder member within which the pump piston member defines at least one pumping chamber having inlet and outlet passages, said pump piston and pump cylinder members being relatively movable with respect to each other in alternating strokes along a predetermined axis to provide pumping pressures in the pumping chamber within a desired high pressure range, one of said pump members having a driving connection for engagement and movement of that member in opposite directions along said axis by an alternating driving element for the pump, a supporting element for normally holding the other of said pump members at a fixed position along said axis, and a resilient attachment between the supporting element and the other of said pump members, said resilient attachment being prestressed to resist relative movement of the other of said members along said axis with respect to the supporting element when the pumping pressures within the pumping chamber are within the desired range, but permitting such relative movement of the other of said members along said axis with respect to the supporting element and thereby reducing the relative axial alternating movement of the pump piston with respect to the pump cylinder when the pressures in the pumping chamber exceed the desired range, said resilient attachment including a pressure control chamber separate from said pumping chamber and a pressure control system connected to said pressure control chamber and maintaining a predetermined control pressure therein.

Claim 3

A suction and delivery pump particularly useful for high pressure spray installations which do not require additional air, said pump comprising a pump piston member and a pump cylinder member within which the pump piston member defines at least one pumping chamber having inlet and outlet passages, said pump piston and pump cylinder members being relatively movable with respect to each other in alternating strokes along a predetermined axis to provide pumping pressures in the pumping chamber within a desired high pressure range, one of said pump members having a driving connection for engagement and movement of that member in opposite directions along said axis by an alternating driving element for the pump, a supporting element for normally holding the other of saId pump members at a fixed position along said axis, and a resilient attachment between the supporting element and the other of said pump members, said resilient attachment being prestressed to resist relative movement of the other of said members in each direction along said aixs with respect to the supporting element when the pumping pressures within the pumping chamber are within the desired range, but permitting such relative movement of the other of said members in each opposite direction along said axis with respect to the supporting element and thereby reducing the relative axial alternating movement of the pump piston with respect to the pump cylinder when the pressures in the pumping chamber exceed the desired range.

Claim 4

A suction and delivery pump particularly useful for high pressure spray installations which do not require additional air, said pump comprising a pump piston member and a pump cylinder member within which the pump piston member defines at least one pumping chamber having inlet and outlet passages, said pump piston and pump cylinder members being relatively movable with respect to each other in alternating strokes along a predetermined axis to provide pumping pressures in the pumping chamber within a desired high pressure range, one of said pump members having a driving connection for engagement and movement of that member in opposite directions along said axis by an alternating driving element for the pump, a supporting element for normally holding the other of saId pump members at a fixed position along said axis, and a resilient attachment between the supporting element and the other of said pump members, said resilient attachment being prestressed to resist relative movement of the other of said members in each direction along said aixs with respect to the supporting element when the pumping pressures within the pumping chamber are within the desired range, but permitting such relative movement of the other of said members in each opposite direction along said axis with respect to the supporting element and thereby reducing the relative axial alternating movement of the pump piston with respect to the pump cylinder when the pressures in the pumping chamber exceed the desired range.

Claim 5

A suction and delivery pump particularly useful for high pressure spray installations which do not require additional air, said pump comprising a pump piston member and a pump cylinder member within which the pump piston member defines at least one pumping chamber having inlet and outlet passages, said pump piston and pump cylinder members being relatively movable with respect to each other in alternating strokes along a predetermined axis to provide pumping pressures in the pumping chamber within a desired high pressure range, one of said pump members having a driving connection for engagement and movement of that member in opposite directions along said axis by an alternating driving element for the pump, a supporting element for normally holding the other of said pump members at a fixed position along said axis, and a resilient attachment between the supporting element and the other of said pump members, said resilient attachment being prestressed to resist relative movement of the other of said members along said axis with respect to the supporting element when the pumping pressures within the pumping chamber are within the desired range, but permitting such relative movement of the other of said members along said axis with respect to the supporting element and thereby reducing the relative axial alternating movement of the pump piston with respect to the pump cylinder when the pressures in the pumping chamber exceed the desired range, the resilient attachment including two annular pistons supported to slide axially in close engagement between two cylindrical co-axial surfaces, one of which is associated as part of the supporting element and the other of which is associated as part of that pump member which is connected to the supporting element, limiting stops with each cylindrical surface to limit the relative axial movement of the annular pistons, the annular pistons and cylindrical surfaces defining an annular pressure control chamber separate from said pumping chamber, and a pressure control system connected to said pressure control chamber and maintaining a predetermined control pressure therein.

Claim 6

A suction and delivery pump particularly useful for high pressure spray installations which do not require additional air, said pump comprising a pump piston member and a pump cylinder member within which the pump piston member defines at least one pumping chamber having inlet and outlet passages, said pump piston and pump cylinder members being relatively movable with respect to each other in alternating strokes along a predetermined axis to provide pumping pressures in the pumping chamber within a desired high pressure range, one of said pump members having a driving connection for engagement and movement of that member in opposite directions along said axis by an alternating driving element for the pump, a supporting element for normally holding the other of said pump members at a fixed position along said axis, and a resilient attachment between the supporting element and the other of said pump members, said resilient attachment being prestressed to resist relative movement of the other of said members along said axis with respect to the supporting element when the pumping pressures within the pumping chamber are within the desired range, but permitting such relative movement of the other of said members along said axis with respect to the supporting element and thereby reducing the relative axial alternating movement of the pump piston with respect to the pump cylinder when the pressures in the pumping chamber exceed the desired range, the resilient attachment including two annular pistons supported to slide axially in close engagement between two cylindrical co-axial surfaces, one of which is associated as part of the supporting element and the other of which is associated as part of that pump member which is connected to the supporting element, limiting stops with each cylindrical surface to limit the relative axial movement of the annular pistons, the annular pistons and cylindrical surfaces defining an annular pressure control chamber separate from said pumping chamber, and a pressure control system connected to said pressure control chamber and maintaining a predetermined control pressure therein.

Claim 7

A pump according to claim 2 in which one of the two coaxial cylindrical surfaces is an external cylindrical surface of the pump cylinder member, and the other coaxial cylindrical surface is an internal cylindrical surface of the supporting element, which thereby provides at least part of a housing for the control chamber.

Claim 8

A pump according to claim 4 having a main frame, a motor-driven rotary driving shaft with an eccentric thereon, the piston member having a rod connected to the eccentric, and the supporting element being pivotally supported on the main frame for swivelling movement on an axis parallel to the rotary driving shaft.

Claim 9

A pump according to claim 3 in which the pressurized fluid is a liquid, and the pressure control system includes a pressure accumulator having a movable partition dividing the accumulator into a pressurized gas compartment and a pressurized liquid compartment, and a connecting fluid conduit between the control chamber and pressurized liquid compartment.

Claim 10

A pump according to claim 6 in which the connecting conduit between the control chamber and pressure accumulator includes a flow controlling device haVing a one-way valve portion to permit free liquid flow from the control chamber to the accumulator and having a restricted return passage shunted around the valve for limiting the liquid flow in the opposite direction.

Claim 11

A pump according to claim 7, which also includes a pressure vairation damping device having a damping chamber connected to the control chamber, and a spring-loaded damping piston movable in the damping chamber against its spring-loading in response to pressure increases in the control chamber.

Claim 12

A pump according to claim 8 in which the damping device includes an auxiliary pump chamber, a pumping piston portion moving integrally with the damping piston, a conduit having a discharge valve between the auxiliary pump chamber and damping chamber, an inlet suction valve in the auxiliary pump chamber, a reservoir for hydraulic liquid, and a connecting conduit between the auxiliary pump chamber inlet valve and the reservoir.

Claim 13

A pump according to claim 9 in which the pressurized liquid compartment of the pressure accumulator has an adjustably calibrated relief valve with an outlet orifice connected to the reservoir.

Claim 14

A pump according to claim 9 in which the connecting conduit between the auxiliary pump chamber inlet valve and the reservoir includes a three-way valve member for selective connection of the auxiliary pump chamber to a supply of liquid under pressure.