US2119285A - Vibrator - Google Patents

Description

May 31, 1938. T. H. MORGAN VIBRATOR Filed July 50, 1936 2 Sheet s- Sheet 1 77/0/1145 #055420 mean/v ATTORNEY y 31, 1938- T. H. MORGAN 2,119,285

VIBRATOR Filed July 50, 1936 2 Sheets-Sheet 2 E- 5 I H .56 if] 16.4 V

.' I: 5 l\ I MM I N VEN TOR.

ATTORNEY Z6 Mom's #058420 MaQGA/V' Patented May 31, 1938 UNITED STATES PATENT OFFICE VIBRA'I'OR Thomas Hubbard Morgan, Kittanning, Pa. Application July so, 1936, Serial No. 93,400

. 9 Claims.

This invention relates to improvements in vibrators of the reciprocating type, and more particularly to fluid-operated or pneumatic vibrators capable of operation at high frequencies.

Vibrators of the character stated are particularly advantageous in connection with the con- .veyance and classification of materials, the vibrations thereby produced setting the particles or constituents of the materials in motion, whereby said materials may be transferred in a conduit from place to place, or may be graded according to their specific gravities, sizes, etc. upon a suitable screen or table.

My invention contemplates a vibrator of the character stated having a high compression stroke, whereby the reciprocating piston is cushioned and retarded at the end of each alternate movement for rapid reversal of direction and resulting high frequency operation. I

A further object is to maintain a substantially constant flow of fluid through the vibrator for greater eiiiciency and economy.

I also contemplate the provision of means for selectively varying the stroke of the vibrator for unequal vibrations, to adjustably control and provide relatively high vibrations in one and the same direction.

Additional objects are to provide a device which is simple and inexpensive, and which will operate at relatively low pressures with a minimum consumption of operating fluid.

My invention may be more readily understood from the following description, taken in connection with the accompanying drawings, wherein:

Fig. 1 is an end elevational view of a high frequency vibrator embodying my invention;

Fig. 2, a longitudinal section thereof taken on the line II--II of Fig. 1;

Figs. 3, 4, 5 and 6, detail sections taken on the 40 respective lines III-J11, IVIV, V-V and VI--VI-of Fig. 2;

Fig. 7, a view similar to Fig. 2, showing amodifled form of my invention;

Fig. 8, a sectional view thereof, taken on the 45 line VIII-VIII of Fig. 7; and

Fig. 9, a detail sectional view taken on the line IXIX of Fig. 7.

Referring to thadrawings, and particularly to Figs. 1 to 6 inclusive, 2 designates a cylinder hav- 50 ing closure heads 3 and I secured thereto in any suitable manner, as by bolts 5. An intake manifold 6 extends longitudinally of the cylinder and i may comprise an integral part thereof, or as shown, may be separately formed and secured to 55 the cylinder walls as by bolts or screws I. This manifold has a central passage 8 in communication with a fluid inlet conduit 9 connecting with any suitable source of supply of fluid under pressure, as for example, compressed air. l0 designates a central inlet port extending from the passage 8 to the interior of the cylinder 2.

Extending longitudinally of the manifold 6 on either side of the central port 8, and out of direct communication therewith, are fluid chambers lla and llb, the exponents being employed to designate right and left hand relation with respect to the center of the vibrator. At their inner ends, the chambers lla and llb communicate with the interior of the cylinder 2 by ports l2a and I2!) respectively, said ports being spaced equidistant longitudinally on either side of the central inlet port Ill. The outer ends of the chambers respectively communicate with the interior of the cylinder adjacent the ends thereof by ports I30, and l3b.

A piston or plunger I4 is provided for reciprocation within the cylinder, said plunger having a central groove IS in the periphery thereof for coaction with the ports I0, I21; and lZb, the longitudinal dimension of the groove l5 being such as to provide enclosing communication between the central port l0 and either of the said inner ports l2a and l2b, depending upon the right or left hand location of the piston l4. Ilia and l6b designate exhaust ports in the cylinder 2 adjacent the ends thereof.

The ends of the piston l4 are provided with inclined passages "a and "b for establishing communication with the ports I31; and l3b and their respective ends of the cylinder. The said inclined passages are cut diagonally through the peripheral edges of the piston ends, opening through the end faces and peripheral surface of 'the piston, as clearly shown in Figs. 2 and 5.

One end of the piston I4 is drilled or formed with a longitudinal bore l8, disposed eccentrically of the longitudinal axis of said piston, for the purpose of receiving a guidestud l9 secured in the head 4 as by a threaded engagement 20. A spring 2l surrounds the inner end of the stud l9, and is seated in the bore. l8, and contacts an abutment 22 onthestud, said spring being operable in a manner hereinafter described. The function of the guide I!) is to insure proper alinement of the cooperating and registering ports in the piston and cylinder, by preventing relative rotation of the said parts without interference with the reciprocation of the piston. i

It willv be understood that vibrations are produced with my invention by a rapid reciprocation of the piston, whereby the change of directional movement of said piston causes alternating reactive forces to be imparted to the cylinder and to the device to which said cylinder may be attached or connected.

The operation of my invention is as follows. Withthe piston H in the left-hand end of the cylinder 2, as in Fig. 2, the exhaust port ISD is closed by the piston, and the said end of the cylinder is in open communication with the pressure supply line 9 through piston passage i'lb, port l3b, chamber Ill), and ports lZb, l and inlet chamber 8, the ports I!) and I2?) being connected by means of the groove IS in the piston. Hence, upon applying fluid from line 9,

. through any suitable valve, the applied pressure acts upon the left-hand head b of the piston, moving the same to the right. During this initial or impulse pressure or the beginning of the piston travel, the right-hand end of the piston is subjected to atmospheric pressure due to the open exhaust port lGa, whereby a rapid movement is imparted to the piston.

Upon traversing a distance equal to the longitudinal width of the exhaust ports, the port |6a is closed by the piston and the port I6!) is opened to the atmosphere. Likewise, this travel of the piston 14 closes the port l2b, cutting off the fluid supply to the left-hand end of the cylinder. Under these conditions, the piston continues its movement under the momentum of the applied impulse, until the body of fluid enclosed in the right-hand end of the cylinder 2 is compressed sufficiently to negative the force of momentum, whereby the piston is cushioned and stopped before striking the cylinder head 4.

During the momentum travel of the piston, the port l5 connects the ports I!) and [2a, whereby the right-hand end of the cylinder 2 is opened to the pressure in the supply line 9 through chamber H a, port Ba and passage I 1a of the piston. At the instant after the piston is cushioned as above stated, it is caused to move in a reverse direction under the pressure of the supply source acting upon the right-hand .piston head a, whereupon the operation is alternated from left to right with exceptional rapidity. In moving the piston I 4 from right to left, the other ports and fluid passages will be employed in a like manner, as will be readily understood.

Attention is directed to the free or floating piston M which is operated without striking or hammering against the cylinder ends in the manner of many present pneumatic devices. This actionis due to the provision of a relatively high compression stroke in my vibrator, whereby the piston is retarded and reversed against and by means of a pressure fluid cushion.

The measure or amplitude of vibrations to be produced by vibrators of the character stated is equal to the product of the reciprocating weight and the distance through which it moves. Hence, for a required amplitude, the weight and stroke of the piston may be suitably related by the designer.

However, I have found thatextxeedingly increased efficiency may be obtained by providing the piston of increased diameter, while maintaining its weight at the desired amount, whereby the increased area of the piston will provide suflicient compression pressure in advance of said piston to efiect the proper cushioning retardation above referred to.

It will be observed that the initial portion of the stroke of piston l4 takes place against fluid or air at atmospheric pressure, but upon providing suflicient piston area, I am enabled to provide a compression cushioning in advance of the limits of the cylinder which will effect a rapid deceleration and reversal of the piston.

Vibrator operation without striking or hammering eliminates the attendant noise, and also prevents upsetting of the metal of the piston and cylinder which may result from striking contact and cause injury to the parts. Likewise, it is evident that the striking contact of piston and cylinder must be accompanied by a low compression stroke, whereby the speed and frequency of the vibrations will be less than that obtained by my invention.

' A further important feature of my invention 'resides in the construction and relation of the l0, l2a, I2b, l3a, l3b, [6a and lGb of minimum width or dimension in a direction longitudinally of the cylinder 2 while maintaining their crosssectional or flow areas substantially equal to that of the supply line 9, by extending said ports transversely of the cylinder in the form of slots. The groove IS in the piston is also of minimum depth and has a transverse dimension equal to that of its coacting ports "I, l2a and [2b, and by making the flow area of the chambers Ila. and llb also substantially equal to that of the supply line 9, it will be seen that I maintain a constant and maximum pressure flow through the vibrator circulating passages. The maximum dimension of the said ports being transverse with respect to the direction of movement of the piston, it is evident that the ports are opened to capacity in the shortest possible time interval.

By means of the aforesaid construction, my improved vibrator utilizes the greatest amount of available energy of the operating fluid, by providing for capacity as well as uniform flow therein. Since the flow area through the ports and passages is substantially constant, there will be a constant flow without undesirable expanslon and accompanying pressure losses. By so utilizing the supplied fluid, I am enabled to operate my invention at minimum pressures and at an exceptionally low rate of consumption of fluid.

These factors, together with the cushioning retardation and reversal of the piston, provide for extremely high frequency operation at low cost. For example, I have successfully operated a vibrator of the character herein set forth having an 18-pound piston of 4% inches diameter, on compressed air supplied at 50-90 pounds per square inch gage. The measured speed of said vibrator was from '7000 to 10,000 strokes per minute, with a low consumption of air per minute. This vibrator was found capable of carrying considerably heavy loads when associated with a vibrating screen or a conveyor conduit.

The spring 2|, mounted on the stud 20, functions to insure the proper positioning of the piston [4 when inactive, by preventing said piston from coming to rest in mid-center position. Said spring further provides a means of unbalancing the stroke of the piston by increasing the tension thereof through adjustment of the screw stvd 20.

. of vibration. One or both of the chambers Ha and lib may be provided with a control valve 23 in the form of an apertured tapered plug having a projecting stem 24 threaded to receive a tightening nut 25. A spring 26 is disposed between the nut and the side wall of the manifold 6; whereby the proper tension maybe imparted to the taper flt of the valve or valves to maintain the same in fixed position without leakage.

Suitable handles or wrench faces may be pro vided on the valve stems for manual adjustment thereof as desired. It will be seen that the flow through the chambers I la and 1 lb may be varied while the vibrator is in operation, whereby the desired magnitude of unbalanced vibration may be accurately provided by varying the angular position of the valve apertures with respect to the said chambers.

It will also be noted that by varying the flow of fluid to one or both ends of the cylinder, a differential of speed may be obtained in the piston travel as desired, whereby said piston travels faster in one direction than in the other, and thus sets up vibratory impulses of greater magnitude in one direction than in the other.

Figs. 7 to 9 inclusive illustrate a modified form of my invention, wherein the cylinder 2a is provided with right and left hand inlet ports 21a and 21?) connected with the supply line 9a through adjustable control valves 23a and branch pipes or conduits 28. Exhaust ports Mia and lBb are provided as, before. 7

The piston Ma is formed with angular end ports 29a and 29b respectively coacting with the inlet ports 21a and 21b to alternately admit fluid from the supply line to opposite ends of the cylinder? Said ports are in the form of narrow transverse slots'as before to provide equal flow areas for undiminished passage of the fluid therethrough.

As in the form of Figs. land 2, the piston Ma is of enlarged diameter to provide for a high compression stroke in the manner set forth. The operating fluid will be alternately admitted to the left and right hand ends of the cylinder to reciprocate the piston and produce a vibrating action.

To insure proper registering alinement of the ports in the cylinder and piston, the latter may be provided with a longitudinal slot 30 to receive -a stud or key 3| mounted on the cylinder, whereby-the piston is prevented from rotation relative to its cylinder. See Fig. 9.

In place of the spring 2| of the form of Fig. 2,

a starting button 32 may be provided in one of the cylinder heads, as in Fig. 7, said button having a plunger 33 slidable in a mounting bushing 34 in said head. A spring 35 normally retracts the plunger 33 within its bushingout of engagement with the piston Ma. However, in the event the said piston comes to rest in dead center position, the operator may push the button 32, whereby its plunger 33 engages and moves the piston into registering position for admission 'of fluid through ports 2'") and 29b to start the vibrator in motion.

The vibrator of my invention may be employed for various purposes, said vibrator being connected with the device to be vibrated as by means of the bolts 5 or any other suitable connecting ormounting means whereby the vibrations may be properly related as to their direction with respect to the purpose to be served.

I claim:

1. A vibrator including a cylinder and a piston reciprocable therein, means for alternately admitting fluid to the ends of the cylinder including a pair of fluid supply ports, a pair of exhaust ports adjacent the ends of the cylinder, said ports being in the form of transversely disposed slots having minimum dimension in the direction of piston movement and coacting with the piston to provide a short stroke and high frequency piston movement.

- 2. A vibrator including a cylinder and a piston reciprocable therein, means for alternately admitting fluid to the ends of the cylinder including a pair of fluid supply ports, a pair of exhaust ports adjacent the ends of the cylinder, said ports being in the form of transversely disposed slots having minimum dimension in the direction of piston movement and coacting with the piston to provide a short stroke and high frequency piston movement, the fluid admission means having substantially equal flow areas throughout.

3. A vibrator including a cylinder and a piston reciprocable therein, means for alternately ad'- mitting fluid to the ends of the cylinder includ ing a central inlet port to the cylinder, a pair of fluid chambers on either side of said central port each having an inner port communicating with the interior of the cylinder adjacent said central port and an outer port communicating with an end of the cylinder, the piston having a central port for alternately connecting the central inlet port with said inner ports, said ports and chambers having substantially equal flow areas, a pair of exhaust ports adjacent the ends of the cylinder, the central port andinner and exhaust ports being in the form of transversely disposed slots having minimum dimension in the direction of piston movement and coacting with the piston to provide a short stroke and high frequency piston movement.

4. A vibrator including a cylinder and a piston reciprocable therein, means for alternately admitting fluid to the ends of the cylinder including an inlet port adjacent each end thereof, the piston having a port in each end thereof opening in its periphery and extending outward- 'ly in angular relation through the piston heads for direct communication with the ends of the cylinder, the piston and inlet. ports having substantially equal flow areas, a pair of exhaust ports adjacent the ends of the cylinder, all of said ports being in the formof transversely disposed slots having minimum dimension in the direction of piston movement and coacting with the piston to provide a short stroke and high frequency piston movement.

5. A vibrator including a cylinder and a. piston reciprocable therein, means for alternately admitting fluid to the ends of the cylinder including a pair of fluid ports controlled by the piston, said ports being in the form of transversely disposed slots having minimum dimension in the direction of movement of and in relation to the stroke of the piston, the fluid admission means having substantially equal flow areas throughout, an exhaust port adjacent each end of the cylinder in the form of transverse slots having minimum dimension in the direction of piston movement and controlled by the latter to permit compression of fluid in advance of the piston, thus providing a pressure cushion efiective to retard and reverse the piston movement without striking the ends of the cylinder, and providing a short stroke and high frequency piston movement.

6. A vibrator including a cylinder, a free nonrotatable piston reciprocable therein, said cylinder having a fluid inlet port adjacent each end thereof, the piston having end ports opening in the periphery thereof to register with the inlet ports and extending outwardly in angular relation through the piston heads for direct communication with the end portions of the cylinder, the cylinder inlet ports and piston end ports having substantially equal flow areas preventing pressure drop during communicating flow therethrough, said cylinder also having exhaust ports adjacent the ends thereof in direct communication with theinterior of the cylinder and the atmosphere, means supplying fluid to the inlet ports, the passage of said fluid to the piston and cylinder being controlled by the movements of the piston to alternately stroke the latter.

'7. A vibrator including a cylinder, a free nonrotatable piston reciprocable therein, means providing a'central fluid supply inlet port to the cylinder and longitudinally extending fluid chambers on either side of said inlet port, each chamber having an inner port communicating with the interior of the cylinder adjacent the inlet port and having an outer port communicating with an end of said cylinder, the piston having an arcuate central groove extending within a portion only of its periphery for alternately connecting the inlet port, with the said inner ports, said inlet ports, fluid chambers, inner ports, and central piston groove having equal flow areas preventing pressure drop during communicating flow therethrough, said cylinder also having exhaust ports adjacent the ends thereof controlled by the piston for direct communication with the atmosphere.

8. A vibrator including a cylinder and a piston reciprocable therein, means for alternately admitting fluid to the ends of the cylinder including a pair of fluid supply ports, a pair of exhaust ports adjacent the ends of the cylinder, said ports being in the form of transversely disposed slots having minimum dimension in the direction of piston movement and coacting with the piston to provide a short stroke and high frequency piston movement, and adjustable means for varying the flow of fluid to the ends of the cylinder to vary the frequency of piston movement in opposite directions.

9. A vibrator including a cylinder and a piston reciprocable therein, means for alternately admitting fluid to the ends of the cylinder including a central inlet port to the cylinder, a pair of fluid chambers on either side of said central port each having an inner port communicating with the interior of the cylinder adjacent said central port and an outer port communicating with an end of the cylinder, the piston having a central port for alternately connecting the central inlet port with said inner ports, said ports and chambers having substantially equal flow areas, a

pair of exhaust ports adjacent the ends of the cylinder, the central port and inner and exhaust ports being in the form of transversely disposed slots having minimum dimension in the direction of piston movement and coacting with'the piston to provide a short stroke and high frequency piston movement, and adjustable means for varying the flow of fluid to the ends of the cylinder to vary the frequency of piston movement in opposite directions.

THOMAS HUBBARD MORGAN.

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