US2483318A

US2483318A - Oscillator

Info

Publication number: US2483318A
Application number: US604781A
Authority: US
Inventors: Benjamin J Lazan
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-07-13
Filing date: 1945-07-13
Publication date: 1949-09-27
Anticipated expiration: 1966-09-27

Description

B. J. LAZAN Sept. 2'], 1949.

OSCILLATOR 4 Sheets-Sheet 1 Filed July 13, 1945 INVENTOR Filed July 13, 19 45 B. J. LAZAN OSCILLATOR 4 Sheets-Sheet 2 INVENTOR flea 2w): (11.4240

N A z A L Im a Sept. 27, 149.

R o T A L L I c S 0 4 Sheets-Sheet 3 Filed July 13, 1945 IN V E NTO R fizzy bark 1/ 42m ATTORNEY N A Z A L l B Sept. 27,1949.

R O T A L L I C S 0 4 Sheets-Sheet 4 Filed July 13, 1945 Patented Sept. 27,1949

OFFlCE OSCILLATOR Benjamin J. Lazan, Greenwich, Conn. Application July 13, 1945, Serial No. 604,781

Claims.

This invention relates generally to materials testing apparatus and more particularly to oscillators for producing a vibrating force which is normally used for loading structures or specimens under test.

It is an object of my invention to provide an oscillator having improved means for adjusting the degree of eccentricity of rotatable weights which produce the vibrating force, the magnitude of the force being in proportion to the degree of eccentricity. Another object in this respect is to provide an improved mechanism for adjusting the eccentric weights in such a manner that the adjusting forces are so related to each other as to insure not only ease in varying the eccentricity, but also in reducing to a minimum any wear and tear on the moving parts during operation.

A further object is to provide an improved oscillator in which the rotating eccentric weights and driving mechanism together with the adjusting elements are so arranged in a cooperative relation as to produce a highly compact device and yet have'the parts easily assembled and accessible. In one particular aspect of my invention I accomplish the foregoing and certain other objects by mounting the major portion of the operating structure and adjusting mechanism about a common axis whereby the oscillator is of relatively small transverse dimensions and at the same time have the parts so related as to obtain a reasonable degree of accessibility without in any way sacrificing ease and precision of adjustment of the eccentric weights.

Other objects and advantages will be more apparent to those skilled in the art from the following description of the accompanying drawings in which:

Fig 1 is a longitudinal vertical section taken substantially on the line l-l of Fig. 2;

Fig. 2 is a section taken on line 22 of Fig. 1, parts being shown in elevation for clarity;

Fig. 3 is an enlarged perspective of an eccentric weight and mechanism for adjusting the eccentricity, parts of which are broken away to show details of construction and the weight being shown in its lower position for purposes of clarity whereas the weights are shown in their upper position in Fig. 1;

Fig. 4 is a perspective of one of the combined drive sleeves and guides for the eccentric weights;

Fig. 5 is an elevational view of the shaft racks for adjusting a plurality of eccentric weights;

2 for supporting the eccentric weights by the adj usting racks;

Fig. 7 is a bottom plan view looking upwardly at the underside of Fig. 6; and

Fig. 8 is'a transverse section taken-on line 8-8 of Fig. 1.

In the specific embodiment of the invention disclosed herein for purposes of illustration, I provide a box-like casing I whose bottom side 2 is open to allow assembling of the rotatable force producing mechanism while a base plate 3 normally supports the casing. The force producing mechanism comprises a plurality of coaxial eccentric weights specifically shown as three in number 4, 5 and 6, respectively supported on drive sleeves l, 8 and 9. These sleeves are journalled in ball bearings supported in the casing end wall Ill andalso in transverse bearing supports I l bolted to or otherwise formed as part of the casing. Suitable downwardly removable bearingcaps [2 are held on the bearing supports by bolts l3.

It will be understood that the weights 4 and 1 6 are driven together as a unit in one direction Fig. 6 is a side view of a modified arrangement and the weight 5 is simultaneously driven at the same angular speed as weights 4 and 6 but in the opposite direction. The horizontal force components of the three weights are arranged to cancel out each other while the vertical components of all weights are additive both upwardly and downwardly. This is accomplished in the well-known manner of having the two sets of weights so angularly driven that during rotation the weights 4 and Swill be on one horizontal side of the axis of rotation while the weight 5 is on the diametric opposite side. This leaves only vertical force components by reason of weights 4 and 8 moving toward a vertical plane from one sidev of the axis while weight 5 is moving toward the same point in the vertical plane from the opposite side of the axis, this movement taking place once at the lower side of the axis of rotation and again at the upper side thereof during each revolution thereby producing a vertical vibrating force.

p In my improved arrangement I adjust the radial position of all weights in order to change the centrifugal force produced by the weights and accordingly vary the vibrating force capacity of the apparatus. To do this I have provided a plurality of coaxial sleeves 1,3 and 9 of generally similar construction and hence'the description of one will sufi'ice for all except where otherwise noted. Foreonvenience, the sleeve 1 3 is shown partially isolated in Fig. 4 and. assembled in Fig. 1. It comprises cylindrical bearing portions M at each end with an. intermediate square portion I5 in which a pair of vertical guideway slots I 6 are formed of sufiicient depth so as to intersect a substantial portion of a bore H extending through the entire sleeve length. Disposed in said bore is an axially shiftable hollow rack shaft l8 having rack teeth I9 and cut on fiatted surfaces o each side of; the, shaft. The arrangement of Fig. 4a, in turn, supports the eccentric weight 4 in the manner shown in Fig. 3.

The lengths of the individual sleeves are determined in accordance with the width of the different weights.

The weights may be formed in various man-1 ners one of which as shown in Fig. 3 comprises.

two

main weight segments

23 and 24 held apart by a smaller central segment 25 all of which are bolted as by screws 26. The central segment 25 is; provided with a pair ofverticalslots one of which is shown at 21 for receiving: a pair of: transversely extending combined weight supporting and rack arms 28- and; 29. These arms are 9- and 20, Figs. 3. and, 4, of the axially shiftable rack shaft, [8. whereby it is seen that upon axial movement of, this shaft the inclined rack teeth will cause the rack arms. and weights to-be moved: radially outward or inward, as. the. case may be, and thereby adjust. the, centrifugal force. pro-. duced. by the eccentric weights.

To drive the sleeves I and 9 together in thesame direction while driving sleeve 8, in the opposite direction, I have provided as. shown in- Fig. 1 a, shaft 35. which is keyed as at 36. to. shaft, 18,. This shaft terminates at. its. right end in an enlarged cylindrical portion 31 having; opposite fiatted sides on which rack teeth 38. are formed to mesh with therach arms of weight 6. in iden-. tically the same manner as, that. shown in Figs. 3, and 4 exceptthat the-rack teeth 38 are formed; on a solid member. 5 1Gb as 31. instead oi a hollow rack shaft l8. The sleeves! and 8 are driven directly by bevel gears 33 and while a, bevel, pinion 4 sup o d n a. suit b y iournall d shaft 42 is driven from any suitable electric motor 43. or o her p w sour e. He ce. wei ht, 5 is mtatably driven in one direction and weight 4 rotatably driven in the opposite direction, the driving force being transmitted, Fig. 4, through guideway l6: of sleeve T and thence to rack shaft i8 and key 36, Fig. 1, to shaft 35 which causes rotation thereof with consequent rotation of weight 6 through racks. 38' and rack arms. 28 and 29'.

To radially adjust the weights, it will be'first understood that a rack sleeve 45, Fig. 1, corresponding broadly to rack sleeve, [8, is interposed between the latter sleeve and the left shoulder of enlarged shaft portion 31. Suitable thrust bearings 46 and 41 are disposed at each end ofsleeve 45. Axial shifting of shaft 35 in either of opposite directions will cause the racks 38, and; similar racks on sleeves l8 and 45' to. adjust simultaneouslythe. radial; nQ ition of a l weights.

To effect such axial adjustment of shaft 35 the enlarged portion 31 thereof is provided with a yoke 49 having a suitable thrust bearing 50. A plurality of symmetrically arranged screws 5| are threaded in yoke 49 and are journalled at their opposite ends in one of the journal supports I2 and in the end wall of casing I. To rotate the screws 5| and thereby move yoke 49 and. shaft 35 axially, each screw is provided with a wor-mwheel 52 commonly engaged by aworm 53. This worm may, if desired; be rotated in either of opposite directions by an electric motor 54 in accordance with the magnitude of vibrating force desired.

The weights may be additionally supported as shown in Fig; 6 by screws 56 extending from the

outer weight segments

23 and 24 to an overhanging type of cross member 51 which takes the place of member 30 in Fig. 3. Suitable dowels 58 may be employed between member 51 and the weight supporting rack arms.

From the foregoing disclosure, it is seen that I have provided an. oscillator having a high de gree of transverse compactnessflexibility of operation and control, together with rugg dness as well as many other qualities and characteristics de irabl n a device of t inath d v e be.- ing relatively narrow in its, transverse dimensions, by reason of having the oppositely rotating eccentric weights all mounted about a single common a s o rot i wh l other o th advanta es a s o a e i n and d.-- justing forces largely self-contained within cerain. as g eleme s thereby din t e v necessity of many complications heretofore present in oscillators of other types. It is to. be noted that the weights are of different sizes, proportioned in accordance with the axial distance between each other so as to eliminate any torsional moments about a transverse plane.

The difference, in axial spacing of the weights is caused by the bevel; gear drive interposed; between two of the weights. To obtain axial com;- pactness when the third weight is added but at the same time avoid torsional moments I arrange the masses as described.

It will of course be understood that various changes in details of construction and arrangement of parts may be made by those skilled in the art without departing from the spirit of the invention as set forth in the appended claims.

I claim:

1. An oscillator comprising, in combination, a pluralityof eccentric weights, means for rotating said weights opposite directions from each other about a common axis and in such angular relation to each other as to produce a resultantvibratory force in a predetermined direction, means for supporting said weights for movement radially of said common axis, and means movable axially alongsaid common axis for radially adjusting said weights so as to vary the magnitude of the resultant force. I

2. Anoscillatorcomprising, in combination, a plurality of eccentric weights, means for rotating said weights in opposite directions from each other about a common axis and in such angular relation to each other as to produce a resultant vibratory force in a predetermined direction, and means movable along said common axis for adjusting said weights so as to vary the magnitude of the resultant force, said weights comprising at leasttwo weights rotating together in one direction and spaced; axially along the axis of rotation and another we ght dis se be ween said xi l y spaced weights and rotating in the opposite direction, the axially spaced weights being of different sizes and each of such weights being individually smaller than the intermediate weight, and said intermediate weight being axially spaced from one of the smaller weights a greater distance than from the other smaller weight, and driving mechanism for said weights being disposed within the space that has the greatest distance between the larger weight and one of the smaller weights.

3. An oscillator comprising, in combination, a plurality of weights certain of which rotate in one direction and others in an opposite direction along a common axis and in such angular relation to each other as to produce a resultant vibratory force in a desired direction, means for supporting said weights for movement radially of said axis and means movable along said common axis for radially adjusting at least one of said weights to vary the magnitude of the resultant vibratory force.

4. An oscillator comprising, in combination, a plurality of eccentric weights rotatable in directions opposite to each other about a common axis, individual sleeves arranged coaXially of each other and having transverse guideways intersecting their interiors, journals for said sleeves, transverse rack arms connected to said weights for supporting the same and radially slidable in said guideways, and rack gears disposed within said sleeves for engagement with the rack arms and axially movable so as to efiect radial adjustment of the rack arms and weights attached thereto. 5. An oscillator comprising, in combination, a plurality of eccentric weights rotatable in directions opposite to each other about a common axis, individual sleeves arranged coaxially of each other and having transverse guideways intersecting their interiors, journals for said sleeves, transverse rack arms connected to said weights for supporting the same and radially slidable in said guideways, rack gears disposed within said sleeves for engagement with the rack arms and axially movable so as to effect radial adjustment of the rack arms weights attached thereto, and means for rotatably driving said axially movable racks whereby rotation is imparted from at least one of the axially movable racks through its cooperating rack to the weight attached thereto.

BENJAMIN J. LAZAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Dempsey et a1 Dec. 29, 1936 J ohnstone Dec. 26, 1944 Number