US1655003A - Apparatus for supplying air under pressure - Google Patents

Description

Jan. 3, 1928.

J. C. .WOODFORD APPARATUS FOR SUPPLYING AIR UNDER PRESSURE Filed Jan. I925 Patented Jan. 3, 19 28.

UNITED STATES OSKAIDOSA, IOWA, ABBIGNOB Oil ONE-HAL! Tb VIBGII: D.

cos c. woonronn, or

BARKER, 01 OAK PARK, ILLINOIS.

APPARATUS FOR BUPPLYING AIR UNDER rnzssm My invention relates to apparatus for cupplying air under pressure from sources which contain air under higher ressure than that which is tov be receive in the I spaces to be supplied. My invention 18 of particular service in connection w th apparatus that is employed for supplying pneumatic wheel tires with air. By means of my invention the apparatus may be set to supply the requisite amount of air, and after havm g supplied the requisite amount of air the source of air under higher pressure w1ll be automatically disconnected. With prlor equipment it is necessary to frequently test 5 the ressure of the air that has been supplie a proceeding which is rendered unnecessary by means of my inventlon.

In practicing my invent on piping 1s employed through which air 1s conveyed from 20 its source. there being a valve between the source and the piping, this valve being constrained to move in a closing dlrection. Mechanism is employed that enables or permits the valve to close, this mechanism bein so connected with the piping and of suc construction as to be controlled by the pressure of the air conveyed by the piping, the the air upon.

mechanism being operable by attaining sufiicient pressure, to enable the closure of the valve. Thus, when the apparatus is used for filling pneumatlc tires, the valve which was opened by suitable means for the purpose of supplymg air to such a tire; is enabled to close when the pressure of the air flowing in the piping has reach a predetermined amount. The mechanism that enables the closure of the valve also desirably takes part in opening the valve, this mechanism being preferably constrained to operate reversely upon sufficient reduction of the air pressure to effect, or take part n effecting, the opening ad ustment of the valve.

In the preferred embodlment of the 1nvention said valve is provided with a spring which is enabled to close the valve when the pressure of the air passed to the piping has reached a redetermined value, a result which arlses w th the 8.l d of the valve controlling mechanism described. In the preferred embodiment of the invention the valve controlling mechan sm 13 located in a chamber into which air s discharged from the piping, there being n th s chamber an operating element which 1s Application fled January 21, 1985. Serial 80. S

by the valve REISSU ED moved in one direction by the air admitted to the chamber when the air attains suflicient pressure, and which is constrained to move in the reverse direction when the air pressure has been sufliciently reduced. The aforesaid operating element is in controlling relation to, or is enabled to take partin controlling the mechanism that is adapted to open the valve, and performs this function when the pressure of the air-is sufliciently reduced to permit the operating element of this mechanism to act of itself to secure this result. When the pressure of the air being supplied has reached a predetermined value the operatin element is reversely operated to relieve t e valve of its opening influence and permit it to be closed by its spring. In the preferred embodiment of the invention a ma et is employed in direct opening relatlon to the valve, the circuit of this magnet ,bein gov-' erned by a relay, the circuit of the re ay, in turn, being governed by a switch which includes a movable contactarm which is the preferred form of the aforesaid operating member located within the aforesaid chamber. This switch arm is constrained to engage its contact, when the pressure within the chamber is sufiiciently reduced, to energize the relay, the circuit of the valve opening magnet being closed by the armature switch of the relay each time the relay is energized. When the pressure of the air within the chamber reaches a predetermined value it operates upon a diaphragm which then moves to place the aforesaid switch arm in an open circuit adjustment to de-energize the relay and the magnet controlled by the relay, whereupon the valve is permitted to close. The point at which the diaphragm may thus respond to the pressure of the air received in the chamber may be regulated by a handle or; knob controlled spring, so 4 that the-apparatus will not cease to function until air under the particular pressure dc slred is supplied to the tire or other space that is to be furnished therewith.

-In the. preferred embodiment of the invention the piping is provided with a second valve which is an outlet valve, this second valve being manually opened each time air is to be supplied and being manually closed when air under the desired pressure has been supplied in order that the air may be trapped within this chamber, at this pressure, to maintain the valve controlling mempiping 2, this valve 19 is normally closed to her in the chamber in the adjustment wherein the first valve may remain closed. However, the outlet valve may be omitted to permit an adjustment of the member within the chamber that would cause the, other valve to open were it not for a device that is then employed for rendering this member ino erative. In the case of the electro-magwho control of thesup ly valve in a systemlacking the outlet va e, a manually controlled sw1tch may be employed in the circuit of the relay for the purpose stated.

The invention will beinore fully explained in connection with the accompanying drawing which is a diagrammatic illustration of the preferred embodiment thereof as constructed and arranged for filling pneumatic tires.

The tank 1 contains air under pressure that is much higher than that which is to be supplied to pneumatic tires. Air may be supplied from this tank by way of piping 2. The air passes from the tank into the valve chamber 3 which is connected at its inlet end to the tank and at its outlet end with said piping. A valve 4 is located within the valve chamber and is pressed upon by a spring 5 in a closing direction, said valve bein constrained by the spring to adjust itsel in closed position when no air is to be supplied. The valve chamber is inclusive of an enlargement 6 thereof into which the valve stem 7 projects. This-valve stem is square or polygonal'in contour while the passage in the wall 8 that separates the two parts of the valve chamber and through which the valve stem operates, is circular, so that when the valve is unseated air may flow to the piping. An electro-magnet 9 is provided for opening the valve, the armature of the magnet carrying an operating arm 10 which is fixed upon the armature shaft 11 that passes into the valve chamber portion 6 through air tight bearings. When the magnet is energized the arm 10 is turned to move the valve stem 7 and the valve 4 inwardly against the force of the spring 5 to permit air to flow through the piping. The circuit of the magnet includes the armature switch 12 of a relay 13. The relay circuit includes a controlling switch that is inclusive of an operating switch contact arm 14 and a contact member 15, complemental to this arm. The switch members 14 and 15 are located within an air chamber 16, there being suitable air tight circuit connections 17, 18, extending through the chamber and including the switch members in circuit with the relay winding. When the valve 4 is to be opened the relay 13 is energized to energize the mag net 9 whose armature thereupon opens the valve. If the piping is supplied with an outlet valve, such as that indicated at 19 in connection with the pipe 20 branching from the trap air under pressure within the chamber 16 to hold the switch arm 14 away from the contact 15 when the apparatus is not in use, a result which is secured with the aid of a diaphragm 21 which is subject to the pressure of the air in said chamber and which then moves the switch arm 14 from. its contact 15 through the intermediation of the abutment screw 22 that presses upon the switch arm .14 for this purpose, this abutnicnt screw being carried upon a bracket 22' that is provided upon the diaphragm. When air is to be supplied to the tire, indicated at 23, the branch pipe 20 is first connected with the tire nipple whereafter the valve 19 is opened. When this valve is opened the pressure in the chamber 16 is reduced to permit the spring 24 to move the diaphragm 21 in a direction to move the abutment 22 out of actuating engagement with the switch arm 14. W'hen the abutment 22 is thus withdrawn from the switch arm 14 this switch arm engages its contact 15, the switch arm being constrained to move in a switch closing direction by reason of its own resilience. When the switch 14. 15 is closed, the circuit of the relay 13 is closed. When the relay is energized its armature switch 12 is closed to close circuit through the valve opening magnet 9. The relay winding is shown as being in bridge of the supply mains 25 extending from. the generator 26, the switch 14, 15 being in series with the relay winding and in the same bridge therewith. The armature switch 12 of the relay is serially included with the winding of the magnet 9 and in another bridge therewith between the mains 25. The magnet portion of the relay is in the form of a solenoid having an iron core 27 which is thrust outwardly by a spring 28 when the relay is de-energized and against the force of which spring said core is moved when the relav is energized. The iron core of the relay carries a brass rod 29 that is in electrical connection therewith. This brass rod carries metallic flanges or e11- largements 30, 31, that are in electrical connection therewith. and also carries two collars of insulation 32. 33, between which the portion 30 is disposed. The brass rod 29 and the parts 30, 31, 32, and 33, carried thereon, are disposed between the brushes 3.4 of one pair, and the brushes of another lthi which the core 27 has sliding electrical contact, the metallic ring 13 the switch arm 12 then in electric connection with the ring, the winding of the magnet 9, the lower main 25 to the lower brush of the generator 26. When the relay is energized it opens the valve 4 as previously described, whereupon air finds passage through the piping 2, the branch pipe 20, to the tire 23 by way of the opened outlet valve 19, the switch arm 14 having engaged its contact 15 when the valve 19 was initially opened, to enable the magnet 9 to open the valve, as described. When the air fiows through the pipe 2 it is not only received in the tire 23 but is also supplied to the chamber 16 to cause the movement of the diaphragm 21 to the left, whereupon the abutment 22 is pushed against the switch arm 14 to separate this switch arm from the contact 15 to open the relay circuit. The spring 28 is then effective to depress the core 27. When this core is fully depressed the metallic enlargement 31 is disengaged from the brushes 35 to open circuit of the magnet 9 which includes the left hand one of these brushes. As the relay 13 is instantly deenergized upon opening of the valve 4, I provide means for retarding the release of the solenoid core 27 to delay opening of the circuit of the magnet. As illustrated, this retarding means includes an apertured plate 36, a valve disk 37 pressed against this plate by a spring 38 to close the apertures therein, an abutment 39 upon the rod 29 against which the bottom end of the spring 38 is engaged, and a chamber 40 surrounding the rod 29 and its enlargement 31 and enclosing the parts 36, 37, 38 and 39. This chamber 40 contains oil 41 which seeps slowly around the plate 36 when the spring 28 lowers the solenoid core. The delay effected in the movement of the metallic element 31 out of engagement with the left hand brush 35 is sufficient to permit an appreciable amount of air to be passed to the tire. When the enlargement 31 becomes separated from the left hand brush 35 the magnet 9 is de-ener'gized to permit the spring 5 to close the valve 4. If sufiicient air has not been supplied to the tire the pressure of the air within the chamber 16 again becomes reduced to permit the spring 24 to move the abutment 22 away from the switch arm 14, whereupon this switch arm again engages its contact 15 to again energize relay'13 with the results before described. These operations are repeated until suflicient air is accumulated within the tire whereupon the diaphragm. 21 is again and finally pressed to the left by the air that is then under suflicient pressure to maintain the diaphragm in this position when the outlet valve 19 is closed, an adjustment which is effected before the branch-pipe 20 is disconnected from the tire. The switch 14, 15, remains opened to permit the spring 5 to maintain the valve 4 closed until the branch pipe 20 is connected with another tire requiring rcfilling, whereupon the pressure of the air in the chamber 16 is again reduced by opening the outlet valve 19 to permit the spring 24 to move the diaphragm 21 to the left to release the switch arm 14 and permit it to engage the contact 15 as and with the results hitherto set forth. The pressure at which the diaphragm is to be operated by the air in a manner to maintain the switch 14, 15, opened, is regulable by the knob or handle 42 whose hub 43 is screwed into the tubular extension 44 of the chamber 16. This handle isprovided with an index 45 that may be placed in registry with scale marks provided upon the index bracket 45' and which marks indicate the various pressures to which the apparatus may be adjusted.

The lamp 46 is in bridge with the mains 25, both brushes 35 being in the same bridge with the lamp. When the relay is energized the brushes 35 are connected by the element 31 to light the lamp, and when the relay is de-energized and its core 27 is fully depressed the lamp 46 is extinguished. The lamp will thus intermittently glow during the tire filling process and will cease to glow when the tire is filled. An audible signal such as the bell 47 may also be employed, this bell including an operating electromagnet which is in circuit with the brushes 34 that are connected by the element 30 when the relay is energized to cause the bell to sound when air is being supplied, the bell ceasing to operate when the valve 4 is closed, the bell thus accomplishing audibly what the lamp 46 accomplishes visually. If the generator 26 furnishes alternating current a step-down transformer 48 is desirably interposed between the mains 25 and the bell 47.

If the outlet valve 19 for the piping 2 or the branch pipe 20 is omitted. the pressure in the chamber 16 is not maintained when the valve 4 is closed, the switch 14, 15 being closed when the valve 4 is closed. To prevent the switch, when normally or idly closed, from energizing the relay 13, I employ a switch 49 in series with the switch 14, '15, this switch 49 being opened when the switch'14. 15 is idly closed and being closed when the apparatus is being employed for its purpose. Either of the elements 19, 49 serves to start the apparatus into operation, the element 19 functioning when it is opened to permit the passage of air from the piping, and the element 49 functioning when it is closed to connect the relay in circuit.

I claim In a device for charging a receiver with compr ssed air, the combination of a source of com ressed air, adjustable means for limitin the ultimate pressure to which said receiver is to be charged, a conduit connecting the source of compressed air with the receiver, a valve in said conduit, means tending to close said valve, means opening said valve when the pressure in the conduit falls to that at which the device is adjusted, and

means timin the open interval of said valve, 10 whereby In witness whereof, I hereunto subscribe 15 my name.

JOE C. WOODFORD.

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