US1064204A - Fluid buffer device for elevators. - Google Patents

Description

I P. G. PURLOW. H4111) BUFFER DEVICE FOR ELEVATORS.

APPLICATION FILED FEB. 4, 1911.

' Patented June 10, 1913.-

( g mme Mo;

K 95x3 A) Sign 1e Unirn stains Parana rice.

FLOYD C. IFURLOW', OF MONTCLAIR, NEW JERSEY,

ASSIG-NOR '110 OTIS ELEVATOR. COM- PANY, F JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

., FL UID BUFFER DEVICE FOR ELEVATORS.

Specification of Letters Patent.

Patented June 10,1913;

Original application filed October 9, 1907, Serial No. 396,553, Divided and this application filed February Serial No. 606,468.

To all whom it may concern:

Be it known that I, Fnovn C. Funnow, a citizen of the United States, residing at Montclair, in the county of Essex and State of New Jersey, have invented a new and useful Improvement. in Fluid Butter Devices for Elevators, of which the following is a specification.

My invention relates to safety buffers for elevators, and this application is a. division of my co-pending application, Serial No. 896,553. filed October 9 1907, for fluid dashpot buffer device.

The invention consists of a device for gradually retarding an elevator car or other moving element independently of its operating apparatus, so as to bring the parts gradually to rest without shock or jar.

The invention also comprises means for resetting or returning the buffer device to its initial position, when the same is released by the moving part of the elevator which is arranged to engage the butter device.

The exactnature of the invention and the specific objects sought-to be attained will appear hereinafter in connection with the detailed description of the invention and the appended claims.

In the accompanying drawings, Figure 1 represents an elevator system illustrating an application of my invention: Fig. 2 is a vertical sectional elevation of my improved buffer device including the resetting means.

In general my invention comprises a butter device or shock absorber'adapted to overcome the inertia of a moving body in an elevator in gradually stopping the same.

In the drawings I have shown the butter device in position to be engaged by the elevator car as it approaches its lower limit oftravel, although obviously it might be placed in the path of the counterweight or other moving part which it is desired to stop gradually, where such part is in an ele-' vator system or other analogous apparatus.

In Fig. 1 two cushioning devices of the form shown in detail in Fig. 2 are shown at the bottom of the elevator well in position to be engaged by the elevator car as the same approaches'its lower limit of travel.

and by the combined retarding action of springs and a varying fluid pressure, bring the 'car to a complete stop gradually and inweight of the car and the 'car. near the dependently of manual controllers, although the car may be descending at a high rate'of speed. I

Fig. 1 illustrates a typical hydraulic elevator of the well known plunger type, the elevator car 1 traveling along the usual guide rails (not shown). To the bottom of the car is securely attached the plunger 2 uhich is arranged to move up and down freely in the main cylinder 18. The latter supplied with fluid under pressure through the to-and-from pipe 16 from the pressure supply pipe 14 through the change valve 17. 15 designates the discharge or exhaust pipe. The operation of the change valve 17 is controlled by means of a hand lever 10 in the car coiiperating with the standing ropes 9, the sheave 11, the pinion 12 and the rack bar 13 in the well known manner. The standing ropes 9 are fastened at 8 to the overhead beam 6. The cable 4 is attached to the upper side ofthe car and extends upwardly over the sheave 5, mounted on the overhead beam 6 to the counterbalance weight 7. The counterweight partially balances the combined weight of the car and plunger. The cylinder 18 is closed at its lower end by a head 19 and when the car operating lever 10 is moved in one direction or the other, the change valve 17 will be operated to open or closed position to allow the supply pressure to act on the plunger to lift the car or so as to cause the unbalanced plunger andload to force the fluid out of the cylinder through the exhaust pipe 15.

Although in some instances only one buffer device would be suflicient, it would be preferable in stopping an elevator car to employ a plurality of them. In this instance I have shown two buffer devices 20 in Fig. 1 at the lower limit of travel of the elevator car, and so placed in respect thereto that each will be engaged by the bottom of lower limit of the cars travel.

Referring now to Fig. 2 which shows the invention in detail, a heavy compression spring 21 is loosely mounted in a; short tube or inverted cap 22 secured to the top of a tubular piston rod 25. The spring 21 is surmounted by a rubber helps to deaden the blow cushion 23 whichof the elevator car or other moving part when it strikes the lltt butter. The lower end of the piston rod is screwthreaded to receive a collar 26 bol tgyd on to a piston 27. The piston rod is provided with a series of perforations 28 near its lower end. A tubular casing 29 is screwthreaded. into a support or standard 30 which is provided with holes 31 for bolts or other fastening means to securely hold the butter device in proper position.

The bottom of the casing '29 is provided with a recess 32 which is screwthreaded to receive the lower screwthreaded end of a tube 33. Within the tube 33 is a hollow rod 34 extending from the bottom of the tube 33 up through acentral opening in the piston 27 and into the piston rod 25. Surrounding the rod 234i. is a coil spring 35 which rests on the tube and terms a resilient stop for the piston 27 and parts carried thereby. The hollow rod 34 provided with a series oi. graduated openings 36 extending fromnear the top of the rod to a point a short distance above the top of the tube These openings are of gradually diminishing diameters from the top one which is large enough to oilr-cbut little or practically no resistance to the flow of oil therct-hrough. to the lowest openii'lg which will allow the oil to pass only very slowly. A coil spring; 37 yieldingly holds the piston 27 in its upper position and returns it to such position after the butter device has operated. Bolted to the upper end of the casingQt-l is a hollow cap 38 which storms a liquid receptacle. This cap surrounds thedlollow piston rod 25 and is provided with a stutfinp; box 39 to guide the tube 25 and prevent escape of the liquid. Openings 38' in the cap 38 permit the escape of air displaced by the piston rod 25 as it descends. and including the cylinder 29 and cap 38 is filled with oil or other liquid. The hollow rod 3'4 is therefore also filled. Any suitable'lirpiid such as wal'er'or oil may be used. lVhile itmay be possible to use water or other similarv liquid or even to have the cylinder contain only air, I prefer to employ oil since it prevents rusting" or corrosion, does not evaporate appreciably and at the same time lubricates all themoving parts. Furthermore. there is no possibility of the oil. freezing and thereby rendering the device inoperative.

The operation of the buffer device is substantially as follows: V Vhen the elevator car or other moving part which it is desired to bring to a gradual stop and which maybe traveling at a high rate of speed, strikes the butter, the spring 21 is compressed and the piston rod 25 and'piston 27 start gradually downward. The spring 21 acts as a cushion for the piston rod and piston and thus prevents them from receiving a sudden and violent blow and also permits them to-be started gradually. The rubber cushionQS The receptacle. taken as a whole also serves to further deaden the blow. the piston 27 commences its downward'move ment, the oil beneath it is forced into the hollow rod 34, the oil in the rod being forced oullvard through the top of the rod and the openings 36 which are above the piston, and through the openings 28 into the space above the piston.' As the area of the openings both above and below the piston is large;

very little resistance is offered to the flow of the oil during the initial movement of the piston, and the latter is enabled to accelerrate very rapidly. T hat is. it quickly takes up the running speed of the car. the back pressure due to the inertia of the piston and. piston rod in starting being absorbed by the spring 21. The: circulation of the oil as above noted continues as the piston d escends. the restriction to the flow oi. oil gradually becoming greater as the number and size of the openingswiG below the pistoii diminish. W hen the piston has covered the last opening 36, it will be brought to rest. owing to the incompressible nature of the oil. unless there is leakage between the piston 27 and the cylinder 29. or between the piston and the rod 34, in which case it may mo re far enough to compress the spring 35. and will then be brought to an absolute stop. The spring will act as a buli'er to stop the ca r without any in case it is not brought to a com plete stop by the retarding effect of the oil.

.Vhile I have described my invention in connection with an elevator system. there are doubtless other uses to which my inven tion could be put to great advantage with. outiuvention. Various changes in the details and arrangement of parts might also be made by those skilled in the art without departing from the spirit. and, scope oi the invention. I desire therefore not to be limited to the particular construction and an rangement of parts disclosed.

lVhat I claim as new and desire to secure by Letters Patent of the United States is 1. Tu an elevator buffer. the cmubination ot a cylinder. a piston movable therein. a hollow piston rod. and a hollow member stationanv with respect to the cylinder. extending through the piston and into the piston rod and formed to permit a gradually re stricted' passage of a fluid through said piston rod from one side of the piston to the other during the movement of the piston.

2. In an elevator buller. the combination of a cylinder. :1. piston movable therein and. provided with an opening. and a hollow member movable relative to the piston through said opening and provided with an opening oropenings in position to gradually restrict the passage of a liquid from one side of the piston to the other.

3. In an elevator buffer, the combination of a cylinder, a-piston therein provided with an. opening, and a hollow rod within the cyl- ALS inder and extending through the'sa-id opening, said rod being formed with a series of lateral openings arranged to successively oppose the piston.

4. In an elevator buffer, the combination of a cylindrical casing, a cylindrical hollow rod within the casing and formed with a series of graduated lateral openings, a piston formed with an opening through which the said hollow rod extends, and a pistonrod.

5. In an elevatorbutfer, the combination of a receptacle, a piston movable therein, a hollow piston rod connected to the piston, and a stationary hollow'rod in the'receptiacle and extending through the piston into the piston rod, said stationary rod being formed with a series of lateral openings.

6. The combination of a cylindrical receptacle, a piston movable therein and having a substantially liquid tight fit in the receptacle, and a hollow cylindrical rod within the receptacle and slidable through an opening in the piston which forms 'during such movement a substantially liquid tight joint with the rod, said hollow rod being provided with an opening or openings in' position to gradually restrict the flow of a liquid from one side of the piston to the other as itmoves in the receptacle.

7. In an elevator bufl'er, the combination of a cylindrical receptacle, a piston formed with an opening, a hollow piston rod, and

a hollow stationary member located in the receptacle and extending through said opening into the hollow piston rod, and a series pf lateral openings in the said hollow mem- J81.

8. In an elevator butter, the combination ofa vertical stationary receptacle, a liquid therein, a piston movable vertically in the receptacle and formed 'with an opening therethrough, a hollow stationary member extending through said opening and provided with a lateral opening or openings of position and size to effect a gradual throtgig tling of the liquid as the piston moves downward, and means carried by the piston to be engaged by a moving part of the elevator.

9. In an elevator buffer, the combination of a receptacle, a piston and hollow piston rod movable therein, a liquid within the receptacle, a cap or cover for the receptacle formed with an opening through which the piston rod extends; a hollow cylinder stationary within the receptacle and extending through the piston into the piston rod, said cylinder and piston rod being formed with lateral openings in position to permit a transfer of the liquid-from the lower side to the upper side of the piston and effect a gradual throttling of the liquid as the piston descends.

10. In a butler device, the combination of a cylinder, a piston movable therein, a liquid in the cylinder, means for gradually restricting the flow of liquid as the piston is moved, and resilient means for retarding the piston brought into operation after the operation of said restricting means.

11. In an elevator buifer, the combination of a receptacle liquid therein, a member movable through the liquid, means for gradually restricting the transfer of liquid from one side to the other of said member during such movement, and a resilient device to bring the said movable member to a ,full

stop after the operation of said means.

12. In an elevator bufier, the combination of a receptacle, a piston movable therein, a hollow member extending through an opening in the piston and formed with openings to variably retard the movement of the piston, and a spring or springs to reset the buffer.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses. Y

FLOYD C. FURLOW.

Witnesses:

ELEANOR W. CALLAIIAN, W. H. BRADY.

Images