Monitoring system for pneumatic cylinder

Claim 2

A pneumatic cylinder monitoring system comprising in combination: a pneumatic cylinder having a coaxial cushion bore at the forward end thereof and a piston movable therein from a retracted position to said forward end in a power stroke; said piston having a coaxial cushion plug thereon adapted to enter and cut off the cushion bore from the cylinder at the end of the piston stroke and thereby provide a cushioning area between the piston and said end of the cylinder; a plunger-type fluid pressure control valve connected at one end with the cushioning area of the cylinder and at the other end with the cushion bore to receive pressure therefrom at opposite ends and operate in response to a pressure differential therebetween at the end of the piston stroke to provide a fluid pressure pulse output through the valve as a monitoring signal for the cylinder operation; and control means connected with said valve for operation in response to said pulse output.

Claim 3

A pneumatic cylinder monitoring system as defined in claim 1, wherein said control valve comprises a valve casing and a longitudinally movable cylindrical valve plunger therein controlling an annular passageway between coaxial fluid-pressure inlet and outlet chambers in connection with said control means and being spring-biased at one end to move to the closed position and block said passageway, and wherein the pressure connections therefor with the cushioning area of the cylinder and the cushion bore are through a pilot or inlet chamber in the valve casing at each end of the valve plunger to apply pressure thereto, the connections being such that the pressure from the cushion bore is applied at said one end of the valve plunger tending to hold the passageway blocked and the valve closed in aiding relation to the spring bias, and that the pressure from the cushioning area is applied at the opposite end of the valve plunger tending to open the passageway and the valve in opposition to the spring bias and the cushion bore pressure.

Claim 4

A pneumatic cylinder monitoring system comprising in combination: a pneumatic cylinder in an elongated cylinder casing with a coaxial cushion bore at the forward end thereof and a forward operating port for the cylinder in the casing at the cushion bore; a piston movable in said cylinder from a retracted position to said forward end in a power stroke and having a coaxial cushion plug thereon adapted to enter and cut off the cushion bore from the cylinder at the end of said stroke, thereby to provide a compression or cushioning area between the piston and said end of the cylinder; means providing a pressure leadage path in the cylinder casing between the cUshioning area and the cushion bore; a pulse generating control valve comprising a valve casing and a longitudinally movable cylindrical valve plunger therein controlling an annular passageway between coaxial fluid pressure inlet and outlet chambers and being spring-biased at one end to move to the closed position and block said passageway; said valve being connected with the cushioning area and the cushion bore to receive pressure therefrom at opposite ends of the plunger and operate in response to a pressure differential therebetween at the end of the piston stroke and provide a fluid pressure pulse output through the valve as a monitoring signal for the cylinder operation, and said pressure connections being such that the pressure from the cushion bore is applied at said one end of the valve plunger tending to hold the passageway blocked and the valve closed in aiding relation to the spring bias, and the pressure from the cushioning area is applied at the opposite end of said plunger tending to open the passageway and the valve in opposition to the spring bias and the cushion bore pressure; and control means connected with one of said valve chambers for operation in response to said pulse output.

Claim 5

A pneumatic cylinder monitoring system comprising in combination: a pneumatic cylinder in an elongated cylinder casing with a coaxial cushion bore at the forward end thereof and a forward operating port for the cylinder in the casing at the cushion bore; a piston movable in said cylinder from a retracted position to said forward end in a power stroke and having a coaxial cushion plug thereon adapted to enter and cut off the cushion bore from the cylinder at the end of said stroke, thereby to provide a compression or cushioning area between the piston and said end of the cylinder; means providing a pressure leadage path in the cylinder casing between the cUshioning area and the cushion bore; a pulse generating control valve comprising a valve casing and a longitudinally movable cylindrical valve plunger therein controlling an annular passageway between coaxial fluid pressure inlet and outlet chambers and being spring-biased at one end to move to the closed position and block said passageway; said valve being connected with the cushioning area and the cushion bore to receive pressure therefrom at opposite ends of the plunger and operate in response to a pressure differential therebetween at the end of the piston stroke and provide a fluid pressure pulse output through the valve as a monitoring signal for the cylinder operation, and said pressure connections being such that the pressure from the cushion bore is applied at said one end of the valve plunger tending to hold the passageway blocked and the valve closed in aiding relation to the spring bias, and the pressure from the cushioning area is applied at the opposite end of said plunger tending to open the passageway and the valve in opposition to the spring bias and the cushion bore pressure; and control means connected with one of said valve chambers for operation in response to said pulse output.

Claim 6

A pneumatic cylinder monitoring system as defined in claim 3, wherein the operating pressure connection for the pulse valve to the cushion bore is through said forward operating port of the cylinder, and wherein the operating pressure connection from the pulse valve to the cushioning area is through a port provided at the forward end of the cylinder and an external connection therefor in the cylinder casing.

Claim 7

A pneumatic cylinder monitoring system as defined in claim 3, wherein means are provided for sealing off said pressure leakage path from the cushion bore and providing a pressure outlet for the cushioning area and connection to said pulse valve from said leakage path.

Claim 8

A pneumatic cylinder monitoring system as defined in claim 3, wherein the pressure leakage path includes a threaded cushion-adjusting screw cavity communicating with the cushioning area and an orifice opening therefrom into the cushion bore, and wherein the valve connection to the cushioning area is through a hollow adapter plug screw-threaded into said cushion-adjusting screw cavity and providing means for closing said orifice and a pressure outlet therethrough from the cushioning area for said connection with said pulse valve.

Claim 9

The combination with a pneumatic cylinder having a cushion bore at the forward end thereof and a movable piston therein having a cushion plug adapted to enter and cut off the cushion bore from the cylinder and provide a cushioning area for the piston at the end of its stroke; of means for deriving and utilizing the cushioning pressure from said area to generate a cylinder monitoring output signal of the pulse type; said means comprising a pressure-operated plunger-type pulse valve connected with the cushioning area and the cushion bore to receive operating pressures therefrom in opposition, and including a passageway between two valve chambers and a valve element responsive to said pressures and movable as a plunger to open and close said passageway and pulse fluid pressure therethrough between said chambers; said valve element being spring-biased to the closed position and movable momentarily to the open position in response to a momentary differential in the pressure from the cushioning area above the cushion bore pressure at the end of the piston stroke, thereby to provide said pulsed fluid pressure as an output monitoring signal and indicate completion of the cylinder operation; and control means connected with one of said valve chambers for operation in response to said pulsed fluid pressure.

Claim 10

The combination with a pneumatic cylinder having a cushion bore at the forward end thereof and a movable piston therein having a cushion plug adapted to enter and cut off the cushion bore from the cylinder and provide a cushioning area for the piston at the end of its stroke; of means for deriving and utilizing the cushioning pressure from said area to generate a cylinder monitoring output signal of the pulse type; said means comprising a pressure-operated plunger-type pulse valve connected with the cushioning area and the cushion bore to receive operating pressures therefrom in opposition, and including a passageway between two valve chambers and a valve element responsive to said pressures and movable as a plunger to open and close said passageway and pulse fluid pressure therethrough between said chambers; said valve element being spring-biased to the closed position and movable momentarily to the open position in response to a momentary differential in the pressure from the cushioning area above the cushion bore pressure at the end of the piston stroke, thereby to provide said pulsed fluid pressure as an output monitoring signal and indicate completion of the cylinder operation; and control means connected with one of said valve chambers for operation in response to said pulsed fluid pressure.

Claim 11

The combination as defined in claim 7, wherein the cylinder is provided with a forward operating port at the cushion bore and the operating pressure connection for the pulse valve with the cushion bore is provided throUgh said operating port, and wherein the operating pressure connection for the pulse valve with the cushioning area is provided through an outlet port and an outlet connection therewith at the forward end of the cylinder.

Claim 12

The combination as defined in claim 7, wherein a pressure leakage path is provided between the cushioning area and the cushion bore comprising a threaded cushion adjusting screw cavity, a passageway therefrom into the cushioning area of the cylinder and an orifice opening therefrom into the cushion bore, and the pulse valve connection with the cushioning area is through a hollow adapter plug screw-threaded into said cavity and having a ball closure element for said orifice and providing a pressure outlet through a tubular core therein from the said cavity and the cushioning area for said pulse valve connection, and wherein a bypass pressure line connection with throttling valve means therein is provided between the cushioning area and the cushion bore.

Claim 13

A pneumatic cylinder monitoring system comprising in combination: a pneumatic cylinder in an elongated cylinder casing with a coaxial cushion bore at the forward end thereof, a piston movable in said cylinder from a retracted position through its travel or stroke to the forward end and having a coaxial cushion plug thereon adapted to enter and cut off said cushion bore from the cylinder at the end of said stroke, thereby to provide a cushioning area between the piston and said end of the cylinder; a piston rod extending forwardly from said piston and cushion plug coaxially therewith through the cushion bore and externally of the casing for connection with a work load movable by the piston; means providing two operating pressure connections with the cylinder, one directly into the cylinder through a port in the casing at the rear end and the other indirectly into the cylinder through a forward port in the casing at the cushion bore; an operating valve for the cylinder for applying pneumatic operating pressure through said connections to either end of the cylinder selectively to move the piston through its travel or stroke or to retract it; control valve means in said cylinder connections for limiting the outflow therethrough from the cylinder while permitting full inflow therethrough to the cylinder, thereby to control the operating movement of the piston; means providing a pressure leakage path in the cylinder casing between the cushioning area and the cushion bore including a threaded cushion-adjusting screw cavity, a passageway therefrom into the cushioning area of the cylinder and an orifice opening therefrom into the cushion bore; a pulse generating valve comprising a valve casing and a longitudinally movable cylindrical valve plunger therein having an intermediate section of reduced cross-section controlling an annular passageway between coaxial fluid pressure inlet and outlet chambers and being spring-biased at one end to move to the closed position and block said passageway; said valve being connected with the cushioning area and the cushion bore to receive operating pressure therefrom through pressure inlet chambers in the valve casing at opposite ends of the plunger and operate in response to a pressure differential in the cushioning-area pressure above the cushion-bore pressure at the end of the piston stroke and provide a fluid pressure pulse output through the valve as a monitoring signal for the cylinder operation; and control means connected with one of said valve chambers for operation in response to said pulse output.

Claim 14

A pneumatic cylinder monitoring system comprising in combination: a pneumatic cylinder in an elongated cylinder casing with a coaxial cushion bore at the forward end thereof, a piston movable in said cylinder from a retracted position through its travel or stroke to the forward end and having a coaxial cushion plug thereon adapted to enter and cut off said cushion bore from the cylinder at the end of said stroke, thereby to provide a cushioning area between the piston and said end of the cylinder; a piston rod extending forwardly from said piston and cushion plug coaxially therewith through the cushion bore and externally of the casing for connection with a work load movable by the piston; means providing two operating pressure connections with the cylinder, one directly into the cylinder through a port in the casing at the rear end and the other indirectly into the cylinder through a forward port in the casing at the cushion bore; an operating valve for the cylinder for applying pneumatic operating pressure through said connections to either end of the cylinder selectively to move the piston through its travel or stroke or to retract it; control valve means in said cylinder connections for limiting the outflow therethrough from the cylinder while permitting full inflow therethrough to the cylinder, thereby to control the operating movement of the piston; means providing a pressure leakage path in the cylinder casing between the cushioning area and the cushion bore including a threaded cushion-adjusting screw cavity, a passageway therefrom into the cushioning area of the cylinder and an orifice opening therefrom into the cushion bore; a pulse generating valve comprising a valve casing and a longitudinally movable cylindrical valve plunger therein having an intermediate section of reduced cross-section controlling an annular passageway between coaxial fluid pressure inlet and outlet chambers and being spring-biased at one end to move to the closed position and block said passageway; said valve being connected with the cushioning area and the cushion bore to receive operating pressure therefrom through pressure inlet chambers in the valve casing at opposite ends of the plunger and operate in response to a pressure differential in the cushioning-area pressure above the cushion-bore pressure at the end of the piston stroke and provide a fluid pressure pulse output through the valve as a monitoring signal for the cylinder operation; and control means connected with one of said valve chambers for operation in response to said pulse output.

Claim 15

A pneumatic cylinder monitoring system as defined in claim 10, wherein the operating pressure connection for the pulse valve with cushion bore is through the forward port in the cylinder casing, and wherein the operating pressure connection for the pulse valve with the cushioning area of the cylinder is through a hollow adapter plug screw-threaded into the cushion adjusting screw cavity and providing ball closuRe means for the orifice and a pressure outlet therethrough from the cushioning area and said cavity for said connection with said pulse valve.