US730121A

US730121A - Unloading means for air-compressors.

Info

Publication number: US730121A
Application number: US13095602A
Authority: US
Inventors: Ebenezer Hill
Original assignee: Individual
Current assignee: Individual
Priority date: 1902-11-12
Filing date: 1902-11-12
Publication date: 1903-06-02
Anticipated expiration: 1920-06-02

Description

No. 730,121. 7 PATENTED JUNE 2, 1903. E. HILL. x UNLOADING MEANS FOR AIR COMPRESSORS.

APPLICATION FILED NOV. 12, 1902.

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No. 730,121; PATENTED JUNE 2, 190a. E. HILL.

. UNLOADING MEANS FOR AIR GOMPRESSORS.

APPLIOATION FILED NOV; 12, 1902.

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'necting the escape-valve UNITED STATES Patented Tune 2,1903.

PATENT OFFICE.

EBENEZER HILL, OF NORWA'LK, CONNECTICUT.

UNLOADING MEANS FOR AIR-COMP RESSORS.

SPECIFICATION forming part of Letters Patent 1\To. 730,121, dated June 2, 1903.

Application filed November 12,1902. Serial No. 130,956.

(No model.)

T0 61/ whom it may concern.-

Be it known that I, EBENEZER zen of the United States, residing at Norwalk, in the county of Fairfield and State of Con necticut, have invented certain new and useful Improvements in Unloading Means for Air-Compressors, of which the following is a specification.

This invention relates to a means for auto matically stopping compression and relieving the pumping-pistons of a multiple-stage compressor from load when the pressure in the system exceeds the desired amount and continuing compression when the pressure in the system drops to normal.

The object is to provideavery simple,cheap, and quick-acting means for relieving all of the pumping-pistons of the compressor from work when the pressure in the system rises above the predetermined maximum. This object is accomplished by connecting an escape-valve with the duct between cylinders which operate at difierent pressures and conwith the system in such manner that the escape-valve will be opened'when the pressure in the system rises above normal and allow air to escape from the interduct and relieve the low-pressure piston of load. The suction-valves of the high-pressure cylinder are held open when the pressure in the interduct drops, so that the high-pressure piston will not force air forward to the receiver when the escape-valve is open and the low-pressure piston is relieved from work.

Figure 1 of the accompanying drawings is a side elevation with parts broken away of connected high-pressure and low-pressure cylinders of a compound air-compressor em bodying the invention. Fig. 2 is a central vertical section, on larger scale, of the escapevalve that is connected with the interduct of this compressor. Fig. 3 is a longitudinal section, on large scale, of a suction-valve of the high-pressure cylinder that is held open when the pressure in the interduct drops below normal.

The first or low-pressure cylinder 1 has ordinary suction-valves 2, discharge-valves 3, and piston 4. The second or high-pressure cylinder 5 has special suction-valves 6, ordinary discharge-valves HILL, a citidisk is guided in its 7, and piston 8. The two cylinders are joined in the usual manner and are connected by an intercooler 9, and the two pistons are connected by a rod 10 and are adapted to be connected with a steampiston. The discharge from the high-pressure cylinder is connected with the receiver 11, from which the air is supplied to the system at the desired pressure. Connected with the interductthat is, the ductthrough the intercooler from the loW to the high pressure cylinders-is an escape-valve 12. The upper end of the escape-valve casing is open to the atmosphere, and in the upper part of the casing and adapted to close the escape-port is a valve-disk 13. This valve-disk is connected by a rod 14 with a plunger 15. The valvemovement toward and from the seat around the port by a disk 16, that is attached to a post 17, fastened to a bar 18, that is secured across the opening at the top of the casing. The disk 16 fits loosely and lies in a chamber 19 in the valve-disk, the upper and lower ends of which chamber are connected by a passage 20., A ball 21 controls the opening from the lower part of the chamher to this passage. When the valve-disk moves away from its seat, the air in the lower part of the chamber beneath the disk escapes slowly past the edges of the disk and acts as a cushion and requires the valve-disk to open gently. When the valve-disk closes, the air travels freely from the upper to the lower portion of the chamber through the passage 20, so that the closing will be quick.

The plunger is connected by a rod 22 with a weight 23 outside of the casing. The weight normally holds the valve closed. On the weight-rod, which fits loosely in the opening through the lower end ofthe valve-cylinder, is a hand-nut 24, which may be turned on the threads cut on. the rod, so that by engagement with the bottom end of the casing it will limit the upward movement of the valvedisk or look it against movement.

Thereceiver is connected with the escape valve casing below the plunger by a pipe 25. In this pipe is an automatic pressure-valve 26 of ordinary construction. When the pressure in the receiver rises sired degree, the pressure-valve is opened higher than the deagainst its spring, so that the pressure in the receiver will be exerted on the plunger and cause it to lift and open the valve, so that air will discharge from the interduct to the atmosphere. This renders the first or low-pressure cylinder-ineffective without stopping the engine or the movements of the pistons. When the pressure in the system is reduced to normal, the pressure-valve is closed, and the piston, relieved from the system-pressure, is drawn down by the Weight as the air below it escapes through the opening about the rod 22 and the escape-valve is closed.

The suction-valve 27is fastened to a spindle 28, that is supported by a hub 29, held in the cylinder-head 30. A spring 31, thrusting between the flange 32 of the hub and the head 33 of the spindle, tends to keep the suctionvalve closed in the usual manner.

In the plug 34, that is'screwed into the cylinder-head, is a plunger 35, that closely fits the bore of the plug. The plunger is connected with a rod 36, that has a collar 37 movable in an opening in the end of the plug. A spring 38, thrusting between the end of the plug and the plunger, tends to force the plunger toward the head of the spindle. An opening 39 through the flange of the spindlehub allows the air-pressure in the inlet-port 40 in the cylinder-head to be exerted outwardly against the plunger. This pressure, when normal,overcomes theforceofthespring back of the plunger and holds the plunger away from the head of the spindle, allowing the suction-valve to operate freely in the usual manner. When the pressure in the inlet-port is reduced below normal, as when the iuterduct is relieved of pressure by the opening of the escape-valve and the lowpressure piston is put out of commission, the spring thrusts the plunger against the head of the spindle and holds the suction-valve open. With the suction-valve open the highpressure piston is put out of commission, for it merely draws air in and pushes air out through the open inlet-ports.

When the pressure of the airin the receiver exceeds the desired maximum, the pressurevalve in the connection between the receiver and the escape-valve is opened and the system-pressure is exerted on the under side of the plunger, so as to lift it and open the escape-valve and allow the air which has been pumped into the inter-duct by the low-pressure piston to escape to the atmosphere. This renders the 10 w-pressure piston inelfecti've and causes a drop of pressure in the interduct. This drop of pressure in the interduct relieves the pressure on the plunger back of the suction-valve, so that the spring will cause the plunger to hold the suction-Valve open and put the high-pressure piston out of commission. The parts remain in this relation until the pressure in the system falls to normal. Then the pressure-valve in the connection between the receiver and escape-valve closes and allows the weight to close the es- When the escape-valve is closed, the pressure in the interduct immediately rises, and as the pressure in the interduct reaches normal the suction-valve is freed, so that it can resume its natural function. By reason of this simple construction the high and low pressure pistons are rendered ineffective and the engine quickly relieved of load without being shutdown when the pressure is greater than desired and without waste of energy.

The invention has been illustrated and described as applied to a compound compressor; but it is equally applicable for compressors having more than two stages of compression, and while the term air-compressor has been used throughout the specification it is to be understood that the term air is intended to apply to any gas. The specification has described but one suction-valve. The high-pressure cylinder of compressors of this class is provided with more than one suction-valve, and any number of these suction-valves may be provided with the means for holding them open when the pressure in the interduct drops.

I claim as my invention- 1. In a multiple-stage compressor, the combination with cylinders operating at different pressures, of an escape-valve controlling an outlet from the duct between the cylinders, a communication between the system beyond the high-pressure cylinder and said escapevalve, whereby-the escape-valve is moved to open the outlet from the interduct when the pressure in the system beyond the highpressure cylinder exceeds the predetermined maximum, and a valve controlling an opening into the high-pressure cylinder and adapted to be rendered inoperative by the drop of pressure resulting from the opening of the escape-valve, substantially as specified.

2. In a multiple-stage compressor, the combination with cylinders operating at difierent pressures, of an escape-valve controlling an outlet from theduct between the cylinders, a communication between the system beyond the high-pressure cylinder and said escapevalve, Wherebythe escape-valve is moved to open the outlet from the interduct when the pressure in the system beyond the high-pres sure cylinder exceeds the predetermined maximum, a pressure-valve controlling the communication between the system beyond the high-pressure cylinder and the escapevalve, and a valve controlling an openinginto the high-pressure cylinder and adapted to be rendered inoperative by a reduction of the pressure between the cylinders, substantially as specified.

3. In a multiple-stage compressor, the combination with cylinders operating at different pressures, of an escape-valve controlling an outlet from the duct between the cylinders, means for keeping the escape-valve closed, a communication between the system beyond the high-pressure cylinder and said escapecape valve.

valve, a pressure-valve controlling the communication between the system beyond the high-pressure system and the escape-valve, and a suction-valve of the high-pressure cylinder adapted to be held open whenever the pressure is reduced in the duct between the cylinders, substantially as specified.

4:. In a multiple-stage compressor, the combination with cylinders operating at different pressures, of an escape-valve connected with the duct between the cylinders, means for keeping the escape-valve closed, a plunger connected with the escape-valve, and a communication between the system beyond the high-pressure cylinder and the escape-valve casing below the plunger whereby, when the pressure in the system exceeds the predetermined maximum, it will actuate the plunger sure drops below normal, substantially as 30 speci fied.

EBENEZER HILL.

Witnesses:

E. HILL, Jr., 1-1. H. MOSSMAN.