US772115A - Adjustable retarding device for reciprocating valves. - Google Patents

Description

PATBNTED 00T. 11, *1904.`

l H. P. THOMPSON. ADJUSTABLE RETARDING DEVICE POR RECIPROCATINGrl VALVES.'

APPLIOATION FILED NOV. `19, 1903.

3 SHEETS-SHEET 12 N0 MODEL.

PATENTED 00T. 11, 1904.

l H fP. THOMPSON. ADJUSTABLE EETAEDING DEVICE E oE-EEQI-PROGATING VALVES.

APPLICATION FILED NOV. 19, 1903.

3 SHEETS-SHEET 2.

N0 MODEL.

PATENTED OCT. 1l, 1904-..

E. E. THOMPSON. i ADJUSTABLE EETAEDING DEVISE EOE EEGIEEUGATING VALVES.

APPLICATION FILED NOV.19, 1903.

3 SHEETS-SHEET 3.

.N0 MODEL.

,WW @SNN 1 ww UNITED STATES Patented october 11, 1904.

HUGH PERRONET THOMPSON, OF CHICAGO, ILLINOIS.

ADJUSTABLE RETARDING DEVICE FOR RECIPROCATING VALVES.

SPECIFICATION forming part of Letters Patent No. 772,115, dated October 11, 1904. Application filed November 19,1903. Serial No. 181,761. (No model.)

[o @ZZ whom t may concern:

Be it known that I, HUGH PERRONET THOMP- SON, of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Adjustable Retarding Devices for Reciprocating Valves; and I hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, which form part of this specification.

My invention relates to adjustable retarding devices for reciprocating valves.

In the use of mechanism such as pneumatic sewage-ejectors and the like wherein is employed a valve which acts as a combined pressure and exhaust valve, serving to control the pressure within the working chamber, disadvantageous results are found to follow from unduly-rapid movements of the reciprocating controlling-valves, such results-for example, the slamming of the ejector checkvalves in the case of a sewage-ejector-being occasioned by the sudden reversal of pressure conditions within the cylinder due to such rapid alteration of the position of the controlling-valve.

The primary object of my invention is to provide a retarding device for reciprocating valves-such, for instance, as that above described-which shall -prevent unduly-rapid movement of the valves in reversing the pressure conditions in the devices controlled thereby and which shall be efficient and advantageous in use.

More particularly, an object of my invention is to provide such ya retarding device which will be capable of ready adjustment to vary'the degree of resistance interposed by it to the movement of the controlling-valve in either direction.

A further object of my invention is to provide a retarding device of the character described the resistance of which to the movement of the controlling-valve in opposite directions may be independently varied.

A still further object of my invention is to provide a retarding device of the character described which shall offer different resistances during different portions of its excursion and shall effect its maximum retarding action only while the valve is traveling within the critical limits of its throw-that is to say, within that portion of its excursion during which it initially effects the reversal of the pressure conditions in the associated devices.

A yet further object of my invention is to provide a practical, simple, and efficient dashpot mechanism adapted for this and other uses.

In the drawings I have illustrated my invention as embodied in a structure associated with a valve such as that employed as a pressure-controlling' valve in conjunction with pneumatic sewage-ejectors in the well-known Shone system of sewage disposition.

In said drawings, Figure 1 is a top plan view, partly broken away, of a pressure-controlling valve equipped with retarding devices embodying my invention. Fig. 2 is al longitudinal vertical section therethrough, illustrating the mechanism in the position assumed when the exhaust-ports of the controllingvalve are opened to the devices controlled thereby. Fig. 3 is a similar view illustrating the position assumed by the parts when the controlling-valve is in transit to open the pressure-ports to the devices controlled by the valve. Fig. 4 is a similar view illustrating the position of the parts when the controlling-valve has completed its transit and the pressure-ports are opened. Fig. 5 is an enlarged view, in longitudinal vertical section, of the retarding devices. Fig. 6 is a transverse vertical section on line 6 6 of Fig. 5.

Throughout the drawings like numerals of reference refer to like parts.

10 indicates generally the casing of a controlling-valve suitably constructed and comprising generally a cylindrical chamber A11, two annular separated chambers 12 and 13, associated with the respective ends of the cylinder 11, and a chamber 14 for, a D-valve, to be described. y

15 and 16 indicate, respectively, pressure and exhaust pipe connections communicating, respectively, with the annular chambers 12 and 13.

17 and 18, respectively, indicate series of ports connecting the annular chambers 12 and 13, respectively, with the corresponding ends of the valve-chamber 11.

19 indicates a piping-orifice designed for connection with the devices whose pressuresupply is to be controlled.

2O indicates a constantly-open port connecting the annular chamber 12 to the D-valvecontaining chamber 14.

21 indicates a port extending from the chamber 13 to the surface of the chamber 14.

22 andr23, respectively, indicate conduits establishing communication between the extreme ends of the main valve-chamber 11 and the surface of the chamber 14.

24 indicates a D -valve mounted in the chamber 14 and provided with a passage 25, extending therethrough. One'exterior orilice 25 of said passage is extended, so that it constantly covers the port 21 and is capable, as indicated in Fig. 2, of also covering the oriiic'e of conduit 23. The opposite end of the passage 25 isso disposed that when the valve is in the position illustrated in Fig. 3 it registers with the orifice of conduit 22.

26 indicates a valve-lever arm for controlling the movement of the D-valve 24, carried by a rock-shaft 27, to be operated by suitable mechanism not necessary herein to describe.

28 indicates generally the reciprocating member of the main or controlling valve, which comprises, essentially, two heads 29 and 30, mounted upon a common shaft, as shown. These heads 29 and 30 are-spaced apart a less distance than that separating' the ports 17 and 18, so that said ports may be simultaneously covered by the valve-heads, as indicated in Fig. 3, and the heads are so proportioned that when either head reaches such position as to uncover the corresponding ports 17 or 18 the other head closes its corresponding ports, as illustrated inFigs. 2 and 4.

The operation of the parts thus described will be as follows: Assuming that the parts are in the position shown in Fig. 2, it will be obvious that air under pressure in the pipe 15 can find no ingress into the pipe 19, as the ports' 17 are closed by the valve-head 29. On the'other hand, however, the pipe 19 is in open communication through ports 18 and annular chamber 13 with the exhaust-pipe 16, so that air may escape through pipe 19 from the devicesWith which it communicates. It isnoticed that in this position the D-valve 24 is at its' extreme limit of movement to the right, and under such conditions pressure within the pipe 15 is communicated through the annular chamber 12, port 20, chamber 14, and conduit 22 to the left face of the piston-head 29, tending to hold it in position. (Illustrated in Fig. 2.) On the other hand, the conduit 23, communicating' with the opposite end of the valvechamber 11, opens into the D-valve orifice 25', lwhich constantly communicates with the annular exhaust-chamber 13 through the port 21. If now by the operation of suitable exy traneous mechanisms the D valve 24 be thrown to the limit of its movement to the left, the conditions of pressure upon opposite ends of the member 28 will be reversed. Now the pressure constantlyr exerted in chamber 14 is communicated to the conduit 23 and acts upon the right end of the valve, while the left end, communicating through the conduit 22 and D-valve passage 25 with the exhaustchamber 13, is no longer under pressure. Consequently the valve is forced to the left until it reaches the position shown in Fig. 4, where it will remain until the return of the D-valve 24 to its original position to restore the pressure conditions first described. In its movement from right to left it will be noted that before the valveahead 29 uncovers the ports 17 the valve-head 30 covers its corresponding ports 18, thereby disconnecting the pipe 19 from both the pressure and exhaust sides of the exterior piping. Continued movement of the valve, however, subsequently opens the ports 17 to the chamber 11,while maintaining the ports 18 closed, thereby establishing connection between the pressure-pipe 15 and the pipe 19 through the intermediary of the annular chamber 12 and its ports 17 and the valve-chamber 11, as will be clearly apparent from an inspection of Fig. 4.

The parts thus far described constitute a valve construction well known in the art.

At one end of the valve-casing 10, in axial alinement with the chamber 11, I provide a casing 31 for my retarding device of suitable conliguration and construction to provide a reservoir-chamber 32 and a dash-pot cylinder 33.

34 indicates a closure of an opening in the top of the reservoir 32, and 35 indicates a suitable turn-cock at the bottom for draining the reservoir.

36 indicates a stem extending through the reservoir and axially into the dash-pot cylinder 33 at one end and at its other end suitably connected, as by a joint 37, with the valve-head 30. v

38 indicates a dash -pot piston arranged within the cylinder 33 and arranged to slide upon the end of stem 36 between two suitablyseparated stop-abutments 39 and 39, carried by said stem. At its opposite ends the'cylinder 33 is provided with circumferential 4recesses 40 and 40', with Which respectively communicate series of relatively-short longitudinally-extending grooves or channels 41 41,designed to constitute by-pass ways around the piston. Intermediate the recesses 41 and 41 of the cylinder 33 is left an'unbroken cylindrical portion 42, with which the dash-pot piston 38 is adapted to make a close fit. A by-pass is also provided between the ' circumferential recesses 40 and 40 by radial openings 43 and 43 from the recesses 40 and 40", respectively, and a longitudinal connecting- TOO duct 44. Such 'communication between the opposite ends ot' the cylinder 33 is, however, controlled by valves, which I will now describe. At the point of intersection of the duct 44 with each of the openings 43 and 43 is arranged an adjustable valve adapted to control the passage of liquid from the corresponding end of the cylinder 33 into the duct 44.

These two valves are exactly alike in their construction, and I will therefore describe only valve 45 controlling the opening 43, it being understood, however, that the valve 45', controlling the opening43, is of exactly similar construction.

46 indicates a plug overlying` the opening 43 and provided at its outer end With a beveled valve-seat 47.

48 indicates a constantly-open passage extending through the plug 46 radially of the cylinder 33. i

49 indicates an enlargement of the duct 44 surrounding the upper portion of the plug 46.

50 indicates a coacting valve element threaded Jfor adjustment into the casing 31 in registration with the plug 46 and provided in its lower face with a deep recess 51, having its lower annular edge beveled, as at 52, to coact with the seat 47 of the plug 46.

53 indicates a check-nutfor locking the valve member 50 in adjusted positions.

Obviously the adjustment oi' themovable member 50 toward and from the plug 46 varies the size of the opening between the valvesurfaces 47 and 52, and so regulates the flow oi' liquid from the recess 40 into the duct 44. I also provide in my valve means for permitting the i'low of liquid from the duct 44 into the recess 40 not controlled by the valve member 50. This'means comprises generally a passage around the adjustable member controlled by a check-valve opening to permit the iniiow of liquid practically without resistance.

In the specific construction shown, 54 indicates a transverse passage through the plug 46 from the duct enlargement 49 to the-center of the plug. 55 indicatesa central passage from said passage 54 to the outer face of the plug 46. The outlet of the passage 55 is shaped to afford a seat for a small check-valve, preferably a ball 56, caged in the recess 51 of the movable valve member 50. It will be apparent that inloWing liquids may pass from the duct 44 through its enlargement 49 and the passages 54 and 55, raising the ball-valve 56, and then flowing down through the passages 48 without passing through the adjusted opening between the coacting valve-faces 47 and 52, so that the valve 45, considered as a Whole, acts only to control the flow of liquid in one direction and constitutes practically a check-valve having an adjustable by-pass. It will also be clear that the iiow of the liquid of the dash-pot in the opposite direction is controlled by the valve 45/ and may be regulated to a rate entirely different from that of its iow from the left side of the piston to the right. This is of course because the inflow of the liquid to either side of the piston is practically unobstructed through the operation of the check-valves 56 56', while its outflow from each end is independently regulated by adjustment of the corresponding valve member 50 or 50. It will be apparent that the opposite ends of the dash-pot cylinder 33 might not be adapted to hold exactly the same quantity of oil by reason of the introduction of the stem 36 into the left end of the dashpot Without the provision of a corresponding part in the right end. To provide for this variation and also to maintain in available position a constant supply of the liquid to compensate for leakage or loss through other causes, the liquid-reservoir 32 is arranged in communication with the duct 44 by a suitable channel 57, as best illustrated in Fig. 5.

The use and operation of a device constructed as herein set forth will be as follows: Assuming that the D-valve yof the controllingvalve mechanism be operated to throw the controlling-valve 28 from the position illustrated in Fig. 2 to that illustrated in Fig. 4, as heretofore described, the rst part ofthe movement of the valve 28 meets with substantially no resistance from the retarding mechanism, as the lost-motion connection of the dash-pot piston 38 with its stem 36 permits an initial movement of the stem relative to the piston Without change of position of the latter. When, however, the abutment 39 comes into contact with the piston 38, the piston begins its travel to the left, at first interposing comparatively little resistance to the movement of the controlling-valve, as the liquid within the dash-pot passes around the piston through the by-pass ,ways 41. It will be noted that while this condition exists within the dash-pot the main valve-head 3() is traveling over ports 18 to cut them oli from pipe 19 while the valve-head 29 is yet entirelyclosing the ports 17. When now the parts reach the position illustrated in Fig. 3, the piston cuts oli' the by-pass ways 41 and exerts its IOO greatest resistance `to further movement, as

the only passage around the piston 'is now through the regulable valve 45, the passage 44, and back through the check-valve 56 of valve 45 to the right side of the piston. During this period it will be noted that both the pressure-ports 17 and the exhaust-ports 18 of the controlling-valve are closed and that the proportions of the dash-pot construction are such that the dash-pot piston will offer its greatest resistance until the head 29 of' the controlling-valve has partially opened the pressure-port 17 to pipe 19. Consequently the port 17, being opened as slowly as desired, the pressure is applied to the pipe 19 and the mechanism associated therewith gradually. When now the ports 17 are sufficiently opened and the dash-pot piston has traveled such discursion.

tance that its right edge passes the right ends of the by-pass grooves 41, the action of the dash-pot is accelerated by the increased rapidity of the iow of liquid escaping from the left side thereof to the right by the said bypass grooves 41,. The ultimate position of the mechanism is illustrated in Fig. 4, where the parts are shown ready for their return ex- 'Ihe operation of the mechanism upon its return excursion will be apparent from the foregoing description and need not be traced. p

Vhile I have herein set forth and shown in some detail a specific embodiment of my invention capable of accomplishing the results set forth and in its specific construction containing invention, I do not desire to be understood as limiting myself to such construction alone, as it will be apparent that numerous changes might be made in the particular embodiment of my invention without departing from the spirit and scope thereof.

Having described my invention, what I claim, and desire to secure by Letters Patent of the United States, is-

l. In combination with a valve having ports and a reciprocating member arranged to open said ports alternately at opposite ends of its stroke, a valve-retarding device associated with the reciprocating member comprising a casing providing a cylinder and a duct opening into the cylinder only at its ends, a piston arranged for reciprocation in the cylinder between the duct-openings and two Valves in said duct, each adapted to permit the free fiow of liquid therethrough in one direction and adjustable to retard its iiow in the other direction.

2. In a dash-pot structure, a stem, a piston having a lost-motion connection with the stem,

a casing surrounding said piston and a by'- pass way around said piston, arranged to be unaffected by the motion of the piston rela tive to its stem.

3. In a dash-pot structure, a stem, a piston carried by said stem, a casing surrounding said piston provided with a by-pass duct, and a valve Structure in said duct, having two passages therethrough, and comprising a check member for closing one passage, and a means extending to the exterior of the casing for adjusting the size of the other passage.

4. In a dash-pot structure., a stem, a piston having a lost motion connection with said stem, a casing surrounding said piston, and a plurality of by-pass ways around said piston, arranged to afford passages around said piston at different points in its range of movement.

5. In a dash-pot construction, a piston, a 60 casing wherein said piston travels, a by-pass around said piston, and a valve in said by-pass, said valve having two passages therethrough, and comprising an adjustable member for regulating the size of one of said passages, and a 65 check-valve member for closing the other passage in one direction only.

6. In a dash-pot structure, in combination',

a liquid-reservoir, a dash-pot cylinder, a stem extending longitudinally into said cylinder, a 70 piston carried by said stem, a by-pass around said piston, and a passage effecting communication between said by-pass and the reservoir.

In testimony that I claim the foregoing as my own I affix my signature in presence of two 75 witnesses.

HUGH PERRONET THOMPSON. In presence of- GEO. T. MAY, J r., MARY F. ALLEN.

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