Apparatus for automatic pitch compensation in marine vessels

Claim 2

An automatic pitch compensator adapted for the use in a pneumatically operated control circuit in a marine vessel having an engine, rpm of the engine being selected by a speed setting of a governor, the governor having an output reflecting governor response coupled to an engine rpm control device to regulate engine rpm, the engine powering a controllable pitch propeller; the automatic pitch compensator including: a. a compensating air pressure regulating valve (CAPRV) with an inlet port, an outlet port and an exhaust port, the valve having a metering means adapted to meter air under pressure received in the inlet port to a pilot pressure at the output port, the metering means being operably by a metering activation means, b. a governor to regulating valve coupling (GRVC) connecting the metering activation means of the compensating air pressure regulating valve to the governor output so as to transmit governor response to the metering means, so that change in engine rpm from governor set rpm is reflected in governor output, which change is transmitted to the metering activation means of the compensating air pressure regulating valve, so that metering of air pressure fed into the input port of the compensating air pressure regulating valve is changed so as to change pilot pressure in an amount proportional to change in engine rpm from governor set rpm.

Claim 3

An automatic pitch compensator as defined in claim 1 adapted for use with a governor having a mechanical output, in which the governor to regulating valve coupling includes: c. a coupling means operatively connected to the governor output, d. a servo means responsive to governor output to transmit governor response to the metering activation means, to operate the compensating air pressure regulating valve.

Claim 4

An automatic pitch compensator as defined in claim 2, in which the servo means includes: e. a cylinder having inner and outer end walls, an oil inlet port adapted to receive oil under pressure, and an oil outlet port adapted to return oil to a sump, f. a control rod slidable within the cylinder, the control rod having an oUter end in engagement with the coupling means to receive governor response, an inner end having a plug, and a portion of reduced diameter, g. an actuating rod aligned with, and adapted to slide axially relative to, the control rod, the actuating rod having an inner end cooperating with the metering activation means of the compensating air pressure regulating valve so that axial sliding of the actuating rod relative to the cylinder changes output from the compensating air pressure regulating valve, the actuating rod having an outer end having a control bore accepting the plug at the inner the control rod, the actuating rod having an inner end cooperating with the metering activation means of the compensating air pressure regulating valve so that axial sliding of the actuating rod relative to the cylinder changes output from the compensating air pressure regulating valve, the actuating rod having an end of the control rod, and a control port communicating with the control bore, an annular passage being defined by the portion of reduced diameter and the control bore and extending between the control port and the outer end of the actuating rod, the actuating rod further including a bleed means to scavenge oil from the control bore to prevent a hydraulic lock forming within the control bore, h. a piston secured adjacent the outer end of the actuating rod on a side of the control port remote from the inner end of the actuating rod, the piston dividing the cylinder into inner and outer cylinder spaces, the inlet port communicating with the inner cylinder space and the outlet port communicating with the outer cylinder space, i. a first compression spring extending between the piston and the outer end wall of the cylinder so as to urge the piston away from the cylinder, j. a second compression spring extending between the piston and the control rod so as to urge the inner end of the control rod away from the control bore of the actuating rod, relative disposition of the plug and the control bore being such that the plug partially blocks the control port, so that oil leaving the inner cylinder space passes through the control port, is metered by restriction at the control port, and passes at a reduced pressure along the annular passage into the outer cylinder space to leave the outer cylinder space through the outlet port, the oil in the outer cylinder space producing a force on the piston to combine with the spring forces in opposition to force from oil pressure in the inner cylinder space, so that in an equilibrium position force on the piston from oil in the inner cylinder equals force on the piston from oil in the outer cylinder plus force from the springs so that the piston is stationary relative to the cylinder; and movement of the coupling means resulting from a change in engine load moves the control rod relative to the actuating rod thus changing the metering of the oil flow and producing a force difference on the piston thus disturbing the equilibrium and moving the piston in a direction to regain the equilibrium position, movement of the piston moving the actuating rod axially so as to change position of the metering activation means thus altering pilot pressure at the output port in an amount proportional to change in engine load.

Claim 5

An automatic pitch compensator as defined in claim 3 in which the coupling means includes: k. a lever having an upper arm adapted to be linked to the output of the governor, and a lower arm, the lever being hinged for rotation relative to the automatic pitch compensator, l. screw adjusting means provided at the outer end of the lower arm, the means contacting an outer end of the control rod so as to transmit governor response to the control rod and to provide adjustment of the coupling means.

Claim 6

An automatic pitch compensator as defined in claim 3 in which: m. the mid portion of reduced diameter is defined in part by a shoulder adjacent the inner end, the shoulder adapted to serve as a metering means whEn adjacent the control port.

Claim 7

An automatic pitch compensator as defined in claim 2 in which: n. inlet and outlet ports of the compensating air pressure regulating valve includes flow control needle valves to permit adjustment of response of the automatic pitch compensator.

Claim 8

A pneumatically operated control circuit adapted for use in a marine vessel powered by an engine, rpm of the engine being selected by a speed setting of a governor, the governor having an output reflecting governor response coupled to an engine rpm control device to regulate engine rpm, the engine powering a controllable pitch propeller, the pneumatic circuit including: a. a manual control (SLC) receiving air under pressure from a source, the control having valves communicating with a forward pitch line, a reverse pitch line and a throttle line, the valves being operable by an operator so as to selectively meter outputs to each line, b. a pitch control cylinder (PCC) having a forward pitch port and a reverse pitch port, output from the pitch control cylinder being operatively connected to a pitch changing mechanism of the controllable pitch propeller, the reverse pitch line communicating with the reverse pitch port, c. a throttle control (TC) having an inlet port connected to the throttle line, and an output connected so as to control the governor speed setting, d. a compensating relay valve (CRV) having an inlet port, an outlet port, and a pilot pressure input port, the compensating relay valve having a metering means provided between the inlet port and the outlet port, the metering means being activated by pilot pressure at the input port, the inlet port communicating with the forward pitch line and the outlet port communicating through a line with the forward pitch port of the pitch control cylinder, e. an automatic pitch compensator (APC) having an inlet port accepting air under pressure from the supply, an outlet port discharging air at pilot pressure to the pilot pressure input port of the compensating relay valve, and an exhaust pipe to exhaust excess air to waste, the automatic pitch compensator having i. a compensating air pressure regulating valve (CAPRV) having a metering means between the inlet and outlet ports, and a metering activation means actuating the metering means, ii. a governor to regulating valve coupling (GRVC) connecting the metering activation means to the governor output so as to transmit governor response to the compensating air pressure regulating valve so as to change output pilot pressure at the outlet port, the governor response being dependent on load in the engine, f. an accumulator tank in series with the outlet port of the automatic pitch compensator and the input port of the compensating relay valve, so that a pitch signal of a manually imparted signal at the manual control to attain a perdetermined rpm and pitch is modified by a demand from the governor output dependent on load experienced by the engine, the modification altering the manually selected pitch so as to tend to maintain constant rpm.

Claim 9

A pneumatically operated control circuit adapted for use in a marine vessel powered by an engine, rpm of the engine being selected by a speed setting of a governor, the governor having an output reflecting governor response coupled to an engine rpm control device to regulate engine rpm, the engine powering a controllable pitch propeller, the pneumatic circuit including: a. a manual control (SLC) receiving air under pressure from a source, the control having valves communicating with a forward pitch line, a reverse pitch line and a throttle line, the valves being operable by an operator so as to selectively meter outputs to each line, b. a pitch control cylinder (PCC) having a forward pitch port and a reverse pitch port, output from the pitch control cylinder being operatively connected to a pitch changing mechanism of the controllable pitch propeller, the reverse pitch line communicating with the reverse pitch port, c. a throttle control (TC) having an inlet port connected to the throttle line, and an output connected so as to control the governor speed setting, d. a compensating relay valve (CRV) having an inlet port, an outlet port, and a pilot pressure input port, the compensating relay valve having a metering means provided between the inlet port and the outlet port, the metering means being activated by pilot pressure at the input port, the inlet port communicating with the forward pitch line and the outlet port communicating through a line with the forward pitch port of the pitch control cylinder, e. an automatic pitch compensator (APC) having an inlet port accepting air under pressure from the supply, an outlet port discharging air at pilot pressure to the pilot pressure input port of the compensating relay valve, and an exhaust pipe to exhaust excess air to waste, the automatic pitch compensator having i. a compensating air pressure regulating valve (CAPRV) having a metering means between the inlet and outlet ports, and a metering activation means actuating the metering means, ii. a governor to regulating valve coupling (GRVC) connecting the metering activation means to the governor output so as to transmit governor response to the compensating air pressure regulating valve so as to change output pilot pressure at the outlet port, the governor response being dependent on load in the engine, f. an accumulator tank in series with the outlet port of the automatic pitch compensator and the input port of the compensating relay valve, so that a pitch signal of a manually imparted signal at the manual control to attain a perdetermined rpm and pitch is modified by a demand from the governor output dependent on load experienced by the engine, the modification altering the manually selected pitch so as to tend to maintain constant rpm.

Claim 10

A pneumatically operated control circuit as defined in claim 7, in which the governor has a mechanical output and the governor to regulating valve coupling includes: g. a coupling means cooperatively connected to the governor output, h. a servo responsive to governor output to transmit governor response to the metering activation means to operate the compensating air pressure regulating valve.

Claim 11

A pneumatically operated circuit as defined in claim 8 in which the servo means includes: i. a cylinder having inner and outer end walls, an oil inlet port adapted to receive oil under pressure, and an oil outlet port adapted to return oil to a sump, j. a control rod slidable within the cylinder, the control rod having an outer end in engagement with the coupling means to receive governor response, an inner end having a plug, and a portion of reduced diameter, k. an actuating Rod aligned with, and adapted to slide axially relative to, the control rod, the actuating rod having an inner end cooperating with the metering activation means of the compensating air pressure regulating valve so that axial sliding of the actuating rod relative to the cylinder changes output from the compensating air pressure regulating valve, the actuating rod having an outer end having a control bore accepting the plug at the inner end of the control rod, and a control port communicating with the control bore, an annular passage being defined by the portion of reduced diameter and the control bore and extending between the control port and the outer end of the actuating rod, the actuating rod further including a bleed means to scavenge oil from the control bore to prevent a hydraulic lock forming within the control bore, l. a piston secured adjacent the outer end of the actuating rod on a side of the control port remote from the inner end of the actuating rod, the piston dividing the cylinder into inner and outer cylinder spaces, the inlet port communicating with the inner cylinder space and the outlet port communicating with the outer cylinder space, m. a first compression spring extending between the piston and the outer end wall of the cylinder so as to urge the piston away from the cylinder, n. a second compression spring extending between the piston and the control rod so as to urge the inner end of the control rod away from the central bore of the actuating rod, relative disposition of the plug and the control bore being such that the plug partially blocks the control port, so that oil leaving the inner cylinder space passes through the control port, is metered by restriction at the control port, and passes at a reduced pressure along the annular passage into the outer cylinder space to leave the outer cylinder space through the outlet port, the oil in the outer cylinder space producing a force on the piston to combine with the spring forces in opposition to force from oil pressure in the inner cylinder space, so that in an equilibrium position force on the piston from oil in the inner cylinder equals force on the piston from oil in the outer cylinder plus force from the springs so that the piston is stationary relative to the cylinder; and movement of the coupling means resulting from a change in engine load moves the control rod relative to the actuating rod thus changing the metering of the oil flow and producing a force difference on the piston thus disturbing the equilibrium and moving the piston in a direction to regain the equilibrium position, movement of the piston moving the actuating rod axially so as to change position of the metering activation means thus altering pilot pressure at the output port in an amount proportional to change in engine load.

Claim 12

An automatic pitch compensator as defined in claim 1 in which the governor has a mechanical output and in which the governor to regulating valve coupling includes: o. a lever having an outer end adapted to be linked to the output of the governor and an inner end contacting and metering activation means of the compensating air pressure regulating valve, the lever being hinged for rotation relative to the automatic pitch compensator so that movement of the governor output is transmitted to the metering activation means.

Claim 13

An automatic pitch compensator as defined in claim 1 adapted for use with a governor having hydraulic output ports in which the governor to regulating valve coupling includes a hydraulic means responsive to difference in pressure in the governor outputs, the hydraulic means including: p. a cylinder having closed ends, a port being provided adjacent each end with each port communicating with a respective port of the governor outputs, q. an actuating rod having inner and outer ends, the rod being a sliding fit in a bore at one end of the cylinder, the inner end of the rod cooperating with the metering activation means of the compensating air pressure reguLating valve, r. a piston provided at the outer end of the actuating rod, the piston dividing the cylinder into cylinder spaced on either the side of the piston, a port communicating with each space, so that, in response to governor demand fluid flowing out of one governor output enters one port into one cylinder space and displaces the piston within the cylinder, fluid being scavenged from the other cylinder space through the other port, movement of the piston actuating the metering activation means of the compensating air pressure regulating valve so as to change pilot pressure in an amount proportional to governor response.