US786654A - Valve mechanism for hydraulic elevators. - Google Patents

Description

No 786.654. PATENTED APR. 4, 1905. T. LARSSON. VALVE MECHANISM FOR HYDRAULIC ELEVATORS.

APPLICATION FILED JULY 29. 1904.

2 SHEETSSHEBT 1.

'WWTH (55555 5 5*: M mi 6 4.

PATENTED APR. 4, 190

T. LARSSON. VALVE MECHANISM FOR HYDRAULIC ELEVATORS.

APPLICATION FILED JULY 29, 190-1.

2 SHEETS-SHEET 2.

UNITED STATES THURE LARSSON,

Patented April 4, 1905.

PATENT OFFICE.

STANDARD PLUNGER ELEVATOR COMPANY, OF WORCESTER, MASSA- CHUSETTS, A CORPORATION OF NEW JERSEY.

VALVE WIECHANlSIVI FOR HYDRAULiC ELEVATORS.

SPECIFICATION forming part of Lette s la e o. 786,654, dated April 4, 1905.

Application filed July 29, 1904. Serial No. 218,659.

To all whom it may concern.-

Be it known that 1, THURE LARSSON, a subect of the Klng of Sweden and Norway, residing at Worcester, in the county of Worcester and State of Massachusetts, have invented a new and useful Valve Mechanism for Hydraulic Elevators, of which the following is a specification.

The object of this invention is to improve 10 the valve mechanism used .to control hydraulic and other elevators.

In the drawings, Figure 1 is a perspective view of a plunger hydraulic elevator equipped with the improvements. Fig. 2 is a sectional elevation through the valves; and Fig. 3 is a view, on an enlarged scale, of one of the bushings used in the pilot-valve.

In detail, A designates the plunger; B, the cylinder, and O the car, which may have the usual counterweights 1V attached thereto by ropes trained over sheaves 9.

1O designates a double standing controllingrope, the ends of which are trained over sheaves 11 at the top of the well and connected to weight 12. The two strands of the rope pass downward, are crossed between the pulleys 13, arranged on a lever 14, carried by the car, and then pass down around sheaves 15 at the bottom of the well. One strand of said rope is connected to the operating-lever 16.

. A shaft is carried forward on the bottom of the car from the lever let and has a handle 17 extending into the car. This forms a means of ordinary construction for controlling the operating-lever from the car.

The valve mechanism consists of a main valve M and a pilot-valve P. A double automatic or shut-off valve S is also used. A pressure-pipe 18 and an exhaust-pipe 19 are connectcd to the main valve M, which latter connects to the shut-ofi' valve by two connectingpipes 20 and 21. The shut-off valves connect by pipe 22 to cylinder B. On the main-valve stem are arranged a piston 23, a valve 2t, controlling the supply, an intermediate piston 25,

a valve 26, controlling the exhaust, and a piston 27, so that when the main valve is moved to the left pressure will flow in through pipe 18, connection 20, and pipe 22 to the elevator-cylinder and so that when the valve is moved to 5 the right cylinder B will exhaust through pipe 22, connection 21, and pipe 19. The piston 23 is larger than the other pistons and valves.

The left-hand end of the main valve is connected by a to-and-fro pipe 28 to the pilotvalve at two points. The pressure-pipe 18 is connected to the pilot-valve by a pipe 29 and the exhaust-pipe 19 is connected to the pilotvalve by a pipe 30.

The pilot-valve is made up of valves 31 and 32, an intermediate piston 33, and valves 3% and 35, valves 32 and 34 being used as an additional means to prevent leakage when the pilot-'valveis in central position. These parts are arranged so that when the pilot-valve is lowered valves 3% and 35 are opened to connect the lower branch of the to-and-t'ro pipe 28 to the exhaust-pipe 30, and hence to relieve the pressure at the left of the piston 23 to cause the main valve to move to the left and so that when the pilot-valve is raised valves 31 and 32 are opened to allow'connection between the upper branch of the to-andfro pipe 28 and the pressure-pipe 29 to admit pressure on said piston 23 and to cause the main valve to move to the right. The pilotvalves' 31 and 35 work in bushings 200, which have holes 201 bored through the same, so that the flow is graduated corresponding to the opening movement of the pilot-valve in either direction and so that as the pilot-valve returns to central position the flow to or from pipe 28 is gradually cut oil, which will easily stop the movement of the main valve either in opening or closing. The operating-lever 5 16 is connected to a nut 36, which engages screw 37 on the end of a rod 38, fitted to slide and turn in the casing. The end of the rod 38 is connected by an arm 39 to the stem of the pilot-valve. Said rod also carries a widec faced pinion 40, engaging which is a rack &1, extending from the main-valve stem. These parts are arranged so that when the pilot-valve is moved down to cause the mam valve to move to the left said rack 41. will turn said pinion 40 and will cause the screw 37 to run into the nut 36, and thus to move and restore the pilot-valve to its central or normal position, and so that when the pilotwalve is moved up to cause movement of the main valve to the right said screw will be unscrewed from the nut 36 and the pilot-valverestored to normal or central position. The screw 37 and the pinion a0 can move axially to allow the pilot-valve to be moved from the operatinglever 16, the pinion ell) being made wide-faced for this purpose. lt will also be noted that by means of this arrangementwhatever move ment is given to the pilotvalvc will be proportionatel y given to the main valve and that this movement of the main valve restores the pilot-valve to central position. This forms a compact and eilicient pilot-valve mechanism.

The rod 38 extends out through a part rigidly secured to the casing, which has on its inner side a screw cam or helix 4:2 and on its outer face another screw am or helix 43. Rigidly secured to the rod 38 is a helix :4, arranged to face the helix 42, and also a helix 4:5, arranged to face the helix 43. These helices are formed to have the same pitch as the screw 3'? and are set as shown in the drawings. It thus will be seen that the rotating cams .4 and 45 are arranged to face each other and that the stationary cams 42 and 43 are disposed between the same. In practice the high points of the cams are eased oil to correspond to the lap of the valves 24 and 26. This arrangement is usedv so as to prevent a careless operator on the car violently reversing the motion of the car.

As shown in the drawings the parts are in normal position and the operator can move the pilot-valve either up or down from the central position any distance up to its extreme of travel, which lStllQ pitch of said screw 37 or the distance said screw 37 will move when making one revolution in nut 36. Suppose the operator should move the lever 16 hal way down to the position shown at 4:6. This will move the pilot-valve halt-way down and will cause the main valve to move half-way to the left. This movement of the main valve will turn the pinion 40 a half-tufinwhich will restore the pilot-valve to normal position, thelever 16 remaining at position 4.6. This will bring the cams 4st and 4C5 to the vertical position, shown in the drawings; but they have turned halt-way around the distance that the cam is can now be moved into caiii $2 or the distance the cam 45) can be moved into the cam as will only be one-half of a pitch. The operator can now at any time move the lever 16 still lower to increase the speed of tie can but from position as the operator can only move the lever 1b upward to the central position and cannot pass the central position until the high point of the cam 45 is turned back to clear the high point of the cam 43,

which only takes place when the main valve reaches its closed position in its travel to the right. Thus the operator cannot move the operating-lever 16 up past the central position until the main valve reaches its closed or central position. If the operating-lever 16 should be moved half-way up or to position -17, substantially the same action would take place, except that the cams l and 45 would be revolved a half-turn in the opposite direction when the main valve reaches its half-way position to the right to allow the cylinder B to exhaust, whereby the operating-lever 16 can only be moved back to the central position until the high point of the cam 44: is turned back past the high point of the cam as. The same action takes place no matter what degree the operating-lever is moved up or down, as the partial revolution of the cams 44' and 45 is proportional to the movement of the o )QIELidD -lBVGZ 16-that is to say if the lever 16 is moved down to any extent up to a full movement thereof it is locked from being moved back past its central position by cams 45 and 4:23 until the main valve comes back to its central position, or if said lever i6 is moved upward to any extent up to a full movement thereof it is locked from being moved back past -its central position by cams 4A and 42' until the main valve comes back to its central position. This prevents a careless operator from reversing the motion of the car violently or instantaneously, as the main valve must come back easily to its central position by reason of the graduated openings in the pilot-- valve, it being impossible to throw the pilotvalve across the center to alter the gradual centering of the main valve. Each centering movement of the main valve takes place at exactly the same rate of speed as the main valve comes to rest as it moves away from its central position to cause the car to go up and down.

While this construction is of use in any class of elevators employing a pilot-valve, it is of particular advantage in hydraulic plun ger-elevators, because if the motion of the car is violently reversed when going up the plunger is apt to bound in the cylinder or draw air into the cylinder by reason of the momentum of the parts, while if the car is violently reversed when descei'iding a water hammer or blow is caused, which is apt to injure or derange the mechanism. These accidents are avoided by the means described.

It will also be observed that the cams 'i" LU- nish a means for restoring the pilot-valve to normal position after it has been shifted to full limit of its travel. Fl/hen the pilot-valve is not thrown to its full limit of travel, the screw-threaded connection will serve to restore the pilot-valve to normal position; but when either set of cams is brought into engagement, which takes place when the lever 16 is moved to its extreme ,in either direction;

ion

the'cams will act to restore the pilot-valve to normal position. Further, if the screwthreaded connection should break or wear stop the car on its downward run and the" left-hand valve to check and stop the car on its upward run. The right-hand one of said valves is operated from a weighted arm 48, which carries a sheave 49. A running rope is attached to the top ofthe car at 51, passes up over a sheave 52, down around said sheave 49, over a sheave 58, and is secured to the car at Met practically the opposite side thereof relatively to 51. When the car is at the top of its run and starts downward, 51 will take up on the rope 50and 54 will pay out the rope 50 practically at the same speed; but as the car approaches the lower end of its run 54 will not pay out the rope 50 as fast as the same is'being taken up by 51,

owing to the accelerated increasing angular deflection of the rope 'betweensheavc 53 and v 54. Hence the arm48 will be lifted at an i accelerated speed,wl 1ereby the speed ofrthe' 1 car will be slowed down some time before it 1 reaches the bottom of its run, hence insuring a gradual and accurate stopping ofthe car i no matter what was its downward speed. The left-hand shut-off valve is actuated by a similar weighted arm 55, which carries sheave 56. Another running rope 57 is connected to the bottom of the car at 58, passes down around sheave 56, up over a sheave 59, and then is attached to the car at at pracitically the other side thereof relatively to 58. By this: arrangement as the 'car.moves up- ;ward 58 will take up on the running-rope "57 and 60 will pay out said rope; but as the car reaches the uppermost limits of its travel v ;the rope 57. will not be paid out between 60 and 59 as rapidly as it is taken up by 58, owing to the accelerated increasing angular Ideflection of the rope between 60 and 59, and hence the arm 55 will be raised with an accelierating movement and the car gradually and accurately brought to a state of rest at its :upper extreme of travel. These running controlling- ropes 50 and 57 are arranged so that they act only as the car reaches the points where it is desired to slow down and do not act to affect the intermediate full- ;speed movement in either direction.

Referring now to the detail of the shut-off valves, the right-hand one will be described: The arm48 is mounted onashaft which projects inside the casing and carries an arm 61, which connects by link 62 to the valve proper, which consists of a double valve 63 and a ring-valve 64,'m0unted upon a hollow stem 65, the end of which is closed by acheck-valve 66, through which are bored small hoies 67. When the valve is moved to the left, the double valve 63 will close the ports communicating with pipe 21, and this movement can take place as fast as the rope 5O pulls up on the sheave 49, as the check-valve 66 will open to permit the water to flow from the left-hand side of the valve 63 to the right-hand side. When the rope 50 slacks to permit the weighted arm 48 to descend, the movement of the valve to the right will beregulated by the size of the openings 67. In ordinary operation the ring-valve 64 performs no function; but if vthe rope 50 should break the weighted arm 48 will move the valve to an extreme position to the right,

'so that the ring-valve 64 will close the openings into pipe 21.

The small holes 67 make this movement an easy and gradual one and prevent an instantaneous shutoti' to cause a water-hammer. The left-hand shut-off valve is constructed the same as that just described and operates the same, except that it is arranged to operate when the car reaches the uppermost limits of its travel. It will be seen that when the'ri 'ht-hand shut-off valve moves to check and stop the exhaust from the elevator-cylinder, as shown in the drawings, the left-hand shut-off valve still leaves full communication between pipe 20 and pipe 22. Hence althoughthe car is gradually stopped as it-comes to its lowest extreme it is possible to start upward. from the lowest position at full speed. The sameaction takes place when the left-hand shut-off valve comes into operation as the'carl reaches the uppermost part of its travel-that is, the right-hand shut-off valve leaves full communication between pipes 22 and 21-so that it is possible to start down atlfull .speed. i The details of the automatic shut-offvalve are'not claimed in thiscase, as

they are claimed in an application filed of even dateherewith, Serial No 218,660; neither are the arrangements of running ropes which operate the shut-off valves claimed herein, as they are claimed in an application filed July 5-, 1904, Serial No. 215,266.

In this application. for patent I do not intend to clairn,.broadly, an elevator-valve in which a rack-tnd-pinion connection forms part of the connection for restoring the pilot valve and also permits a transverse movement of the pinion, as this subject-nutter is claimed in a prior application for patent on a pilot-valve. filed by me March 13, 1902, Serial No. 98,009; nor in this application for patent do I wish to claim, broadly, the combination of a pilot-valve with means for limiting the distance the pilot-valve may be moved at any one operation, as this subject-matter is claimed, broadly, in an application for patent filed by me June 29, 1903, Serial No. 163,477. 1 intend in this present application to claim IIC the improved details of the main valve and pilot-valve and the various mechanisi s arranged to control the operation of the same I am aware that changes may be made in the construction of an elevator plant without departing from the scope of this invention as expressed in the claims and that certain features covered by the claims may be used in (ii ti'erent constructions and in diiierent combinations. 1 do not wish, therefore, to be limited to the construction I have herein shown and described; but

Vthatl do claim, and desire to secure by Letters Patent of the United States, is 1 1.. .ln an elevator valve mechanism, the combination of a main valve, a transversely-movable pilot-valve, a nut connected to be shifted from the elevator-car, a rod threaded into the nut and movable with the pilotvalve, and a gear-and-rack connection between the rod and main valve, said gear-and rack connection permitting an end wise travel of the rod so that the rotation of the rod will close the pilotvalve when the main valve has been shifted to desired position.

2. in an elevator valve mechanism, the combination of a main valve, a pilot-valve, operating connections for the same, and means for limiting the throw of the operating connections, comprising two facing cams carried by a rotating part, and stationary cams interposed between the facing cams.

in an elevator valve mechanism, thecombination of a main valve, a pilot-valve, connections for operating the pilot-valve from the elevator-car, a threaded connection operated by the travel of the main valve for restoring the pilot-valve to central position, and means for limiting the throw oi the operating connections, comprising two facing cams carried by a rotating part, and two stationary cams interposed between the facing cams, said cams having the same pitch as the threaded connection.

4. in an elevator valve mechanism, the combination of a main valve, a pilot-valve, connections for operating the pilot-valve, means to restore the pilot-valve to central position, means for preventing a reverse of the operating connections except when the main valve is in central position, and graduated openings in the pilot-valve for regulating the movement of the main valve.

5. In an elevator valve mechanism, the combination of a main valve, and a pilot-valve and easing therefor, said pi lot-valve casing having a set of ports constructed to throttle as the recess pilot-valve comes back to its central closed position and another port or passage controlling the flow, the pilot-valve being constructed and arranged to close said passage when the same is in central position and said passage being arranged not to interfere with the-action of the set of ports when the pilot-valve is moved away from its central closed position.

6. In an elevator valve mechanism, a main valve, a pilot-valve, connections for operating the pilotvalve, connections from the main valve for restoring the pilot-valve to central position, openings in the pilot-val ve whereby the main valve will come easily back to central position, and means arranged to prevent areverse until the main valve comes back to its central position.

7. In an elevator valve mechanism, a main valve, a pilot-valve, connections from themain valve for restoring the pilot-valve to central position, openings in the pilot-valve for slowing the movement of the main valve as it come back to central position from a travel in either direction, and means arranged to prevent a reverse until the main valve comes back to its central position.

8. A pilot-valve casing having two inlets, one connected to the pressure and the other to ope "ate the main valve and two outlets one connected to the exhaust and the other to operate the main valve, a port or passage between each inlet and outlet, valves 31 and 35 for controlling the inlets and valves 32 and 34 for closing the ports between the inlets and outlets to prevent leakage when the pilot-valve is in central position.

9. A pilot-valve casing having two inlets, one connected to the pressure and the other to operate the main valve, bushings having ports through which the inlets pass, two outlets from said casing one connected to the exhaust and the other to operate the main valve, port or passage between each bushing and outlet, valves 31 and 35 working in said bushings, and valves 32 and 3 for closing the ports between the bushings and outlets to prevent leakage when the pilot-valve is in central position .ln testimony whereof I have hereunto set my hand in the presenceoif two subscribing. 3

witnesses.

THU'RE .LARSSOIT.

VJ itnesses:

LoUIs W. Son'rrnencrn, ANGIE M. Gopnsan.

Images