US2070956A - Vibrator - Google Patents

Description

Feb. 16, 1937.

J. 'c. PELTON V-I BRAT OR Filed June 25, 193e z sheets-sheet 1 INVENTOR.

J.,. PELToN Feb.-1 6, 1937.

VIBRATOR Filed June 23, 1936 2 Sheets-Sheet 2 INVENTOR.l

ATTOR NEY` 'Patented Feb. 16, 1937 UNITED STATES PATENT AOFFICE 2,070,956 vniaa'ron John C. Pelton, North Hollywood, Calif.-

Application June 23, 1936, Serial No. 86,799

17 Claims.

rI'his invention relates to a method-and means for producing vibrations whereby materials and/or objects may be shaken or vibrated at a. high frequency in a ready, facile and economical manner. The means of Athis invention are applicable to various uses; they may be employed in vibrating cementitious compositions for the purpose of rendering themniore compact, for the purpose of vibrating or shaking tables, classiers, or the like, and for numerous other uses.

Whenever concrete or other cementitious composition is employed, diculties are experienced in producing `homogeneous castings or objects. It is known that whenever hydraulic cement comlfpositions are being employed, excessive quantities of water should not be used since excessive quantities of water reduce the strength of the finished object. When but a small proportion of water is used, however, the composition is relatively stiff and non-plastic, making it difficult to cast and completely fill all of the voids or spaces between reinforcing members, crevices, small openings, and the like which may exist in the object being made. Furthermore, air pockets often form in the composition, producing a finished object having highly undesirable voids.

The production of dense, strong objects is greatly facilitated by vibrating the mold or the composition itself. In many instancesA where concrete is employed, the concrete is rammed or spaded in an attempt to force the concrete into all corners of the molds or forms. Spading is time-consuming and entails a high labor cost. Vibrators for use on concrete have been made heretofore but prior vibrating devices necessitated the use of extremely high speed motors and diiculties with bearings have rendered the use of these devices somewhat unsatisfactory.

The present invention relates to a vibrating means which does not require the use of high speed motors. Moreover, it does not employ unbalanced members rotating at high speed as a source of vibration. As a result, the device of this invention is simple to operate and has an extremely long life.

The method of the invention contemplates si-v multaneous vibration and exhaustion of cementitious compositions and the like whereby the constituents of the cementitious composition are ompacted and any airv present therein is extracted preventing the formation of air pockets, pin holes, or the like. Y

It is an object of the invention, therefore, to disclose and provide means for creating and-distributing mechanical vibrations.

the invention will be described primarily in those 15` embodiments which adapt the invention to the treatment of massive concrete, although it is to be understood that the invention is not limited thereto but instead is capable of many other uses and adaptations. 20

In the drawings:

Fig. 1 is a side elevation of a portable vibrator, particularly adapted for use in the treatment of wet concrete.

Fig. 2 is an enlarged vertical section taken 25 through the device of Fig. 1.

Fig. 3 is a side elevation. partly in section, of a modified form of device.

Fig. 4 is a side elevation, partly broken away,

showing the adaptation of the device to a shaker 30 I table.

As has been stated hereinbefore.,when concrete is used in construction work as, for example, in the construction of buildings, walls, dams, etc., it is highly desirable that a relatively small 35 quantity of water be employed and that the concrete be rammed or spaded into place. The device shown in Figs. 1 to 3 inclusive is particularly adapted to such work. As therein shown, the device includes a motor I which may be of the 4o normal 1400-2000 R. P. M. type. The drive shaft 2 of the motor I preferably carries vanes or paddles 3 adapted to rotate within a housing I provided with a tangential discharge port 5. The drive shaft 2 carries a rotor which, in the 45 particular embodiment shown, comprises a cuplike member 6 carried by the end of the drive shaft. The rotor-6 is slightly spaced from the vanes 3. Removably positioned within the cuplike member 6 is sleeve 1 adapted to be threaded- 50 ly inserted within the member 6. The sleeve 1 carries a liner 8 of a suitable composition, said liner 8 being provided with a conical, axially positioned cavity. The liner 8 may be made from substantially any material, although in ac 55 tual practice it has been found that some of the synthetic resin compositions such as bakelite, particularly when impregnated in fabric. are very satisfactory.

Attached to the housing 4 (which may be integral with the motor housing) is a tubular housing I0. This tubular housing I0 may be removably connected to a iiange II extending from the housing 4. A rod-like member I2 extends through the tubular housing I0 and means are provided. for retaining the rod-like member I2 in axially related position to the rotor 6. Such means may include, for example, a centrally perforated, exteriorly threaded bulkhead I3 which is in threaded engagement with the lower end of the housing I0. Means such as the rings I4 and I5 may be provided whereby the bulkhead I3 may be adjustably positioned within the housing I0. The rod I2 extends through the central port of the bulkhead I3 in a fairly loose it. The bulkhead I3 may be provided with a packing gland I6 whereby packing may be held around the rod I2, thereby sealing the interior of the housing I0. In order to further prevent entrance of grit and dust into the device, a removable cover I'I may be slipped around the tube I2 and attached to the end of the housing IIl as by means of machine screws I8.

The rod I2 may comprise a tube of appropriate length. The upper end of the tube may be provided with a conical head 20 rmly attached to the end of the tube I2. Ports 2| may be formed in the walls of the tube I2 near the upper end thereof. The lower .part of the rod I2 may be provided with a conical perforated head 22.

'Ihe mode of operation of the device above described is as follows:

When it is desired to use the device on concrete being poured into a wall section, for example, the operator holds the device by means of the handles supplied thereon and introduces the lower portion of the rod I2 into the concrete. 'Ihe motor I is energized, causing rotation of the rotor 6. 'I'he member 20 carried by the upper end of the rod I2 will come in contact with the rotor but such contact will be very light and I only by reason of a slight displacement of the axis of the upper end of tube I2 from the axis of the rotor. Such displacement is made possible in view of the length of the tube I2 and the fact that it is not firmly or rigidly held in the bulkhead I3. Momentary contact with the rotor 6 lwill cause the end of tube I2 to rebound. The cone 20 will in this manner repeatedly and lightly contact with the rotating rotor 6. The entire l tubev I2 iscaused to vibrate at a very high frequency and obviously such vibration is transmitted to the concrete into which the lower portion of the tube I2 has been introduced. At the same time, suction is applied to the center of the tube I2, such suction being generated by the vanes 3 and transmitted to the interior of rthe housing I0 and then through ports 2I to the .head 22 of the rod-like member I2. In this manner, concrete Ais energetically vibrated and at the same time any entrapped air is withdrawn through the member I2. As"a result, a dense,

homogeneous concrete is assured.

As has been mentioned hereinbefore, the speed of the driven shaft 2 need not be extremely high, an R. P. M. of 1400-2000 being found very satisfactory. The frequency of vibrations imparted to the lower portion of tube I2, however, is variable, depending somewhat upon torsional stresses imposed upon the tube I2 and the ratio of length annoso of tube between the bulkhead I3 and the rotor 3 and that between the bulkhead and the head 22. In a portable vibrator for use'in concrete work, the distance between the rotor l and the bulkhead I3 may be from about 18 inches to 28 inches whereas the total length of the tube I2 may vary from 4 feet to 10 feet. The .frequency of the vibrations imparted to the tube I2 may also be somewhat controlled by regulating the maximum degree of pressure which can be transmitted longitudinally of the-tube against the rotor 3. This may be controlled by adjusting the position of the bulkhead I3. Attention is called to the fact that a boss or ring 24 is carried by the tube I2 and bears against the bulkhead I3, limiting the upward movement of the tube I2. Downward movement of the tube I2 may be restrained by means of a anged member 25 removably attached to the rotor 6, the flanged member 25 extending beneath the lower and outer edges of the cone 20 carried by the upper end of the tube I2.

Attention is called to the fact that the contact between the head 20 and the rotor B is due to a very minor pivoting action in the bulkhead I3 and when the rotor is actually rotating, the contact between the head 20 and the rotor is sporadic and at no specified or constant frequency. 'I'he only members which rotate at fairly high speed are the vanes 3 and the rotor 6. The tube I2 may rotate but such rotation is very slow and incidental.

It is to be understood that instead of using a rotor which receives the head of the tube I2, the rotor itself may be in the form of a cone and the head of the tube may be concave and adapted to encircle the rotor.

Occasionally when very tall and relatively narrow forms have to be formed with concrete. a form of device illustrated in Fig. 3 may be used to advantage. As there shown, the housing I 0 is provided with an enlarged bell-shaped lower portion. 'I'he entire device is lowered by means of a suitable derrick into the form so that the rod-like member I2 penetrates into the concrete but the device is prevented from entirely submerging in the concrete by reasonof the large surface area presented by the bell 29. As a result, during lor after a pouring operation the device may be lowered into the form so that the bell 29 floats the device on the surface of the still plastic concrete and the concrete then vibrated.

'Ihe device may also be employed in vibrating tables, screens, classiers and other forms of equipment. As shown in Fig. 4, for example, a motor 30 carrying a rotor 3I may be firmly bolted to the frame 32 of a table. A rod-like member 33 restrained from excessive longitudinal or lat-v eral motion by means of a ring 34 also attached to the frame 32 holds the rod-like member in position with respect to the rotor 3|. The free end of the member 33 may then be attached to the table 35, said table 35 being mounted on suitable flexible or resilient supports such as the springs 36. Vibration is thus imparted to the tablel 35 in a very economical manner. Tables of this sort may be used to great advantage in molding tiles or in compacting cementitious compositions in small forms or molds.

Prolonged use of the device will, of course, necessitate replacement of. rotors and cooperating members carried by the rods but since the contact between the rotor and the rod is but momentary, and very irregular, and the relative positions of rotor and rods may be changed, such replacement need be had only after prolonged use of the device.

Although a rather specic form of device has been described in detail, it is to be understood that the invention is not limited thereto and that all changes, modications and constructional details coming within the scope of the appended claims are embraced thereby.

I claim:

l. In a vibrator, the combination of: a balanced rotor,'a rod-like member in axial alignment with said rotor, and means for restraining lateral motion of said rod-like member, said means being spaced from the end of the rod-like member, said rod-like member being adapted to loosely contact the rotor.

2. In a vibrating machine, the combination of a balanced rotor, means for driving said rotor, a housing for said rotor, a rod-like member ex'- tending through said housing, said rod-like member being in axial alignment with said rotor adapted to loosely contact the rotor, and means carried by said housing for restraining lateral motion of said rod-like member at a point spaced from the end of said rod-like member.

3. In a vibrator, the combination of a rotor, motor means for driving said rotor, an exhausting fan driven by said motor, a housing for said rotor, said housing extending in a direction parallel with the axis of said rotor, a hollow rod extending through said housing into loose contact with said rotor, means for restraining lateral motion f said rod carried by said housing, means connecting the interior of said housing with the intake of said fan, and port means in said hollow rod communicating with the interior of said housing.

4. In a, vibrator, the combination of: a rotor, means for driving said rotor, a rod-like member in virtually axial alignment with said rotor, said rod-like member being provided with a head adapted to loosely contact with said rotor upon slight displacement of said member, and means for restraining lateral motion of said member without preventing minor displacement thereof, said restraining means being spaced from said head and from the opposite end of said member.

5. In a vibrator, the combination of: a rotor, means for driving said rotor, a rod-like member in virtually axial alignment with said rotor, said rod-like member being provided with a head adapted to loosely contact with said rotor upon slight displacement of said member, and means, relatively xed with respect to said rotor, for restraining lateral motion of said member without preventing minor displacement thereof, said restraining means being spaced from said head and from the opposite end of said member.

6. In a Vibrator, the combination of: a rotor, means for driving said rotor, a rod-like member in virtually axial alignment with said rotor, said rod-like member being provided with a head adapted to loosely contact with said rotor upon slight displacement of said member, and means, relatively iixed with respect to said rotor, for restraining lateral motion of said member without preventing minor displacement thereof, said restraining means being at a point between 10% and 50% of the length of the member from the head end.

7. In a vibrator o f the character described in claim 4, the provision of means for limiting longitudinal movement of said rod-like member.

8. In a vibrator of the character described in claim 5, the provision of means4 for limiting longitudinal movement of said rod-like member.

9. In a vibrator, the combination of: a rotor, means for driving said rotor, a rod-like member in virtually axial alignment with said rotor, said rod-like member being provided with a head adapted to make circumferentially disposed con-v tact with said rotor upon minor displacement of said rod-like member, and means, relatively xed with respect to said rotor, for restraining lateral motionof said member without preventing minor displacement thereof, said restraining means being spaced from said head and from the opposite end of said member.

10. A portable vibrator comprising: a housing. a motor mounted on one end of lsaid housing, a rotor within said housing, said rotor being operatively connected to said motor, a rod member extending from said housing in substantially axial alignment with said rotor, a head carried by said rod member, said head being adapted to make circumferentially disposed contact with said rotor upon a minor displacement of said member, and means carried by said housing for restraining lateral motion of said rod member without preventing minor displacement thereof.

l1. A portable vibrator comprising: a housing, a motor and exhausting fan driven thereby carried by one end of said housing, a port connecting the intake side of said fan with the interior of said housing, a rotor connected to said motor and positioned within said housing, a hollow rod member extending from said housing in substantially axial alignment with said rotor, openings in said rod member and in communication with the interior of said housing, said hollow member being provided with a head adapted to loosely contact with said rotor upon slight displacement of said member, and means carried by the opposite end of said housing for restraining lateral motion of said hollow member without preventing minor displacement 12. A portable vibrator comprising: a housing, a motor and exhausting fan driven thereby carried by one end of said housing, a port connecting the intake side of said fan with the interior of said housing, a rotor connected to said motor and positioned within said housing, a hollow rod member extending from said housing in substantially axial alignment with said rotor, openings in said rod member and in communication with the interior of said housing, a head carried by said hollow rod, said head being adapted to make circumferentially disposed contact with said rotor upon minor displacement of said rod, and means carried by the other end of said housing for restraining lateral motion of said hollow rod without preventing minor displacement thereof, said means for restraining lateral motion being at a point between 10% and 50% of the length of said rod member from the head end.

13.A portable vibrator comprising: a housing, amotor and exhausting fan driven thereby carried by one end of said housing, a port connecting the intake side of said fan with the interior of said housing, a rotor connected to said motor and positioned within said housing, a hollow rod member extending from said housing in substantially axial 'alignment with said rotor, said hollow member being provided with a head adapted to loosely contact with said rotor upon slight displacement of said member,

openings in 'said rod member and in communication with the interior of said housing, means carried by the opposite end of said housing for restraining lateral motion of said hollow member without preventing minor displacement thereof, and means for limiting longitudinal movement of said rod member.

14. A portable vibrator comprising: a housing, a motor and exhausting fan driven thereby carried by one end of said housing, a port connecting the intake side of said fan with the interior of said housing, a rotor connected to said motor and positioned within said housing, a hollow rod member extending from said housing in substantially axial alignment with said rotor, said hollow member being provided with a head adapted to loosely contact with said rotor upon slight displacement of said member, openings in said rod member and in communication with the interior of said housing, means carried by the opposite end of said housing for restraining lateral motion of said hollow member without preventing minor displacement thereof, said means for restraining lateral motion being at a point between and 50% of the length of said rod member from the head end thereof, means for limiting longitudinal movement of said rod member, and a removable member provided with a face in a plane substantially at right angles to the axis of the rod member, carried by the other end of said housing, whereby the vibrator may be caused to maintain itself on the surface of a body of cementitious material. l

15. A portable vibrator comprising: a-housing, a motor mounted on one end of said housing, a rotor Within said housing, said rotor being operatively connected to said motor, a rod member extending from said housing in substantially axial alignment with said rotor, a head carried by said rod member, said head being adapted to make circumferentially disposed contact with said rotor upon a minor displacement of said member, and means carried by said housing for restraining lateral motion of said rod member without preventing minor displacement thereof, said means for restraining lateral motion being at a point between 10% and 50% of the length of said rod member from the head end thereof.

16. In a vibrator of the character described in claim l5, means for limiting longitudinal movement of said rod member.

17. In a Vibrator of the character described in claim l5, means for limiting longitudinal movement of said rod member, and a removable member provided with a face in a plane substantially at right angles to the axis of the rod member and carried by the other end of said housing, whereby the Vibrator may be caused to maintain itself on the surface of a body of cementitious material.

JOHN C. PELTON.

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