US3830474A

US3830474A - Reciprocatory shaker

Info

Publication number: US3830474A
Application number: US00328190A
Authority: US
Inventors: M Tannenbaum
Original assignee: New Brunswick Scientific Co Inc
Current assignee: New Brunswick Scientific Co Inc
Priority date: 1973-01-31
Filing date: 1973-01-31
Publication date: 1974-08-20
Anticipated expiration: 1991-08-20

Abstract

The shaker comprises a support frame having rods extending in spaced parallel relation longitudinally thereof. A shaker table and a separate bracket are supported, at respective longitudinally spaced points, on said rods for rectilinear reciprocation along the rods. The shaker table is arranged to have a carrier, for articles to be shaken, secured thereto, and a counterweight is secured to the bracket. A pair of timing belts extend around respective gears adjacent opposite ends of the support frame, and the shaker table is secured to the upper run of the belts, with the bracket and the counterweight being secured to the lower run of the timing belts. An adjustable stroke crank means, driven by a motor or the like, oscillates driving gears engaged with the timing belt so that the shaker table and the bracket with the counterweight are reciprocated longitudinally of the rods through equal amplitudes and in respective opposite directions. Thereby, during operation of the shaker, the counterweight substantially balances the shaker table.

Description

[ Aug. 20, 1974 United States Patent [1 1 Tannenbaum RECIPROCATORY SHAKER [57] ABSTRACT The shaker comprises a support frame having rods ex- [75] Inventor: Myron Tannenbaum, East Brunswick, NJ.

gitudinally a separate bracket are supported, at respective longitudinally spaced points, on said rods for rectilinear reciprocation along'the rods. The shaker table is arranged to have a carrier,

tending in spaced parallel relation lon thereof. A shaker table and [73] Assignee: New Brunswick Scientific Co., Inc.,

New Brunswick, NJ.

[22] Filed: Jan. 31, 1973 [21] App! for articles to be shaken, secured thereto, and a counterweight is secured to the bracket. A pair of timing belts extend around respective gears adjacent opposite [52] U.S. Cl. 259/59 [51] Int. B015 11/00 n of the support frame, and the shaker table is se- [58] Field of Search. 259/2, 17, 35, 59, 91, cured to the upper run of the belts, with the bracket 259/92, 93, 94, DIG. 42 and the counterweight being secured to the lower run of the timing belts. An adjustable stroke crank means,

[56] References Cited driven by a motor or the like, oscillates driving gears FOREIGN PATENTS 0R APPLICATIONS engaged with the timing belt so that the shaker table 1 409 780 and the bracket with the counterweight are reciprocated longitudinally of the rods through equal amplitudes and in respective opposite directions. Thereby,

i zx y f lfigf gfi gf during operation of the shaker, the counterweight sub- Attorney, Agent, or Firm-Blum, Moscovitz, Friedman Stantany balances the shaker table & Kaplan 10 Claims, 5 Drawing Figures PATENTED M1920 SHEUZNS all In.

RECIPROCATORY SHAKER BACKGROUND OF THE INVENTION This invention relates to shaker apparatus and, more particularly, to a new and improved shaker apparatus in the form of a reciprocatory shaker.

Shaker apparatus is used to shake a load so as to change the condition thereof in the desired manner. Thus, such apparatus can be used for shaking mixtures contained in suitable flasks or containers so as to provide homogeneous mixtures therein, the material contained in the flasks and which constitutestherewith the load which is acted upon by the shaker being either wholly or partly liquid, solid or any combination thereof.

Most known shaker apparatus have drawbacks resulting primarily from the fact that they experience, during operation, unavoidable unbalanced vibrations which set up undesirably large unbalanced forces. Because of these factors, it is difficult to attain, with conventional apparatus, results which can be reproduced precisely during successive operations of the apparatus. Additionally, it usually is necessary to bolt the apparatus to a massive stationary structure which will absorb the unbalanced forces. This not only creates inconvenience in and of itself, due to the operations required in connection with fixedly mounting the apparatus, but also the fixed mounting limits the apparatus to only one location, thus preventing the apparatus from being conveniently set up on any available support surface.

The above considerations apply particularly to shaker apparatus of the oscillatory type involving the rotation or oscillation of an eccentric weight to attain the necessary oscillation of the shaker apparatus. While attempts have been made to overcome the disadvantages of oscillatory or rotating type shaker apparatus, such attempts generally have not been completely successful. In order to afford reproducible results, precise uniformity of shaking and precise control thereof is absolutely necessary. Such uniformity and control, in a precision-like manner, is extremely difficult to attain in known shaking apparatus.

SUMMARY OF THE INVENTION In accordance with the invention, an improved shaking apparatus is provided in which a shaker table, for mounting a holder for containers to be shaken, is reciprocated linearly, and at the same time, a counterweight is also reciprocated linearly but in the opposite direction to the direction of movement of the shaker table, but through an equal amplitude of movement and in this way the shaker table and containers are reciprocated in a true flat reciprocating plane which has been found to be extremely advantageous over known shaking apparatus devoid of such true linear reciprocation.

The above construction is obtained in a simple and poste ends of the support, with the shaker table being I secured to the upper runs of the belts and the bracket carrying the counterweight being secured to the lower runs of the belts.

Suitable driving means are provided to oscillate at least one of the two sets of gears through a predetermined arc of oscillation. Preferably, such driving means comprises a motor and an adjustable throw crank mechanism connecting the motor to at least one set of gears. Thereby, as the driven gears are oscillated through the predetermined arc, the upper and lower runs of the timing belts are reciprocated in mutually opposite directions and through equal amplitudes of motion. As a result, the counterweight, carried by the brackets secured to the lower runs of the belts, balances the horizontal forces of the platform secured to the upper runs of the belts.

The invention apparatus is readily portable and may be mounted on any suitable support surface, such as a laboratory table or the like, as the forces are substantially completely balanced so that substantially no horizontal force is transmitted to the support surface. Thereby, anchoring of the support frame to a support surface is not necessary. Consequently, the disadvantages of known shaker apparatus are overcome by the reciprocatory shaker of the present invention.

An object of the present invention is to provide an improved shaker apparatus.

Another object of the invention is to provide such an improved shaker apparatus in the form of a reciprocatory shaker.

A further object of the invention is to provide such a reciprocatory shaker in which all horizontal forces are substantially balanced out by a counterweight movable horizontally with a shaker table but in the opposite direction and through amplitudes of movement equal to the amplitudes of movement of the shaker table.

Another object of the invention is to provide such a reciprocatory shaker which need not be anchored in position but may be disposed on any suitable support surface.

The invention accordingly comprises the features of construction, combinations of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of a reciprocatory shaker embodying the invention;

FIG. 2 is a perspective view, partly broken away and partly in section, of the driving mechanism of the reciprocatory shaker shown in FIG. 1;

FIG. 3 is a plan view, partly broken away and partly in section on the line 3-3 of FIG. 4, of the driving mechanism shown in FIG. 2;

FIG. 4 is a vertical sectional view taken on the line 4-4 of FIG. 3; and

FIG. 5 is a vertical sectional view taken on the line 5-5 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1, the shaker embodying the apparatus is generally indicated at as including a casing which encloses a support frame on which there is mounted, for linear reciprocation, a shaker table described more fully hereinafter. The shaker table, which is disposed above the casing 15, is arranged to have mounted thereon interchangeably shaker platforms 20, which are secured to the shaker table by bolts or screws 21 having operating heads 22 which are preferably knurled. Each shaker platform has, on its upper surface, a plurality of clip-type holders 23 in which there may be releasably secured flasks 25 containing the material or materials to be shaken. Casing 15 includes a front wall 16 on which there are mounted the controls andindicators for shaker 10. These controls include a speed indicator 11, a speed control knob 12, an on-off switch 13, and a pilot lamp 14. By virtue of control knob 12, the speed of a motor effecting the reciprocation of the shaker table can be adjusted while paying attention to the speed indicator 11, after the motor has been energized by closing switch 13, whose closed condition is indicated by the pilot lamp 14. As best seen in FIGS. 1 and 4, frame 15 includes a flanged bottom wall 17 which mounts feet 18 for support of the shaker 15 on a support surface.

Referring now to FIGS. 2, 3, 4 and 5, frame 15 has side walls from the upper end of which top wall portions 26 extend inwardly toward each other to define an opening 27. In a manner to be described, a shaker table 30 is supported so as to be normally centered with respect to opening 27. Shaker table 30includes a planar bottom 31 bounded by an upstanding flange 32, and nuts 24, secured to flange 32, are arranged to be engaged by the screws 21 having the heads 22. Thereby, shaker platforms 20 can be interchangeably secured to shaker table 30.

Casing 15 encloses a main frame which is supported on bottom wall 17 of casing 15 and which, in turn, supports the operating elements, including the drive motor, of shaker 10. Frame 35 includes a pair of upright side walls 33 having flanges 34 at the lower end secured to bottom wall 17 of casing 15. Adjacent their left ends, as viewed in FIGS. 3, 4 and 5, side walls 33 have upwardly opening slots 36 with bearing mounts 37 secured to each side wall and centered toward the lower ends of these slots. These bearing mounts 37 rotatably support a shaft 38 which extends outwardly of one end wall, and which, adjacent each bearing mount 37, has a drive gear 40 secured thereto for rotation therewith. The projecting end of shaft 38 has secured thereto a crank arm 41 whose free end is pivotally connected, by a pin 42, to one end of a link 43. The opposite end of link 43 is pivotally connected to a pin 44 on a crank plate 45 which is adjustably mounted, by means of slots 46 and bolts 47, on a relatively large diameter pulley 48. Large diameter pulley 48 is connected, by an endless belt 51, to a small diameter output pulley 52 of an electric motor 50. The throw of crank plate 45 can be adjusted by loosening bolts 47 and then moving the crank plate 45 radially inwardly or outwardly relaaligning another edge of rectangular plate 45 with the desired indicating mark.

Near its rightward edge, as viewed in FIG. 4, each frame side plate 33 is formed with a rightwardly opening notch 56, adjacent each side of which are elongated slots 57 receiving bolts 58 inserted into bearing retainer 61 supporting a shaft 62 carrying a pair of idler gears fixed thereto to'rotate therewith.

A pair of

timing belts

65,65 are trained around the drive gears 40 and the idler gears 60, these timing belts 65 having gear teeth on their inner surface. In a manner to be described, these timing belts form an essential feature of the invention in providing the balanced linear reciprocation of shaker table 30 and shaker platform 20. By virtue of the slots 57 and the bolts 58, bearing retainer 61 can be adjusted to take up the slack in timing belts 65.

Immediately inwardly of each of the pairs of gears 40 and 60, relatively heavy cross beams 63 interconnect the frame side walls 33, being bolted to each of the two side walls. Each of the beams 63 has a pair of apertures 64, with the apertures of the two beams being aligned with each other to receive guide rods 66 anchored to cross beams 63 by C-shape lock washers 67, there preferably being provided two of these washers at each end of each rod 66. Rods 66 are disposed symmetrically with respect to the centerline of the shaker, each somewhat inwardly from a timing belt 65. In addition, rods .66are disposed in a common horizontal plane substantially midway between the upper and lower runs of the timing chains 65.

A generally channel-shaped upper bracket 70 has a large area rectangular base 71 overlaying the upper runs of both timing belts 65, and depending narrower legs 72 which extend downwardly therefrom between the timing belts 65, and each leg has a pair of apertures receiving bushings 73 slidably engaging the rods 66.

tive to the axis of rotation of large diameter pulley 48, g

Thereby, upper bracket 70 is slidable along the rods 66. Adjacent each end of upper bracket 70, a clamping strip 74 extends beneath the upper runs of the timing belts 65 and is secured to base 71 by clamping screws 76. Thereby, upper bracket 70 is movable with the upper runs of timing belts 65. Immediately inwardly of each clamping strip 74, relatively large support beams 75 extend across base 71 of upper bracket 70, and screws 77 secure shaker plate 30 to cross members 75 and to bracket 70. Thereby, shaker plate 30 also is movable with the upper runs of belts 65.

A lower channel-shaped bracket 80, somewhat narrower than upper bracket 70, has a substantially flat base 81 and a pair of upstanding legs 82, each formed with a pair of apertures receiving bushings 83 engageable with guide rods 66, whereby lower bracket is slidably mounted on guide rods 66. Bracket 80 has a dimension, transversely of the shaker, such that its end edges terminate somewhat short of each of the two belts 65. Also, its longitudinal dimension between its legs is substantially less than the corresponding dimension of the upper bracket 70, thus providing clearance between the legs of the upper and lower brackets. A relatively massive counterweight 85, in the form of a substantially rectangular heavy plate, is bolted to base 81 of lower bracket 80 by bolts 87. Outwardly of lower bracket 80, a pair of clamping strips 84 overlie the lower runs of timing belts 65 and are secured to counterweight 85 by clamping screws 86. Thereby counterweight 85 is secured to move with the lower runs of timing belts 65. It will be noted that the clamping strips 74 and 84 are so located that upper bracket 70 and lower bracket 80 can be readily adjusted longitudinally of the respective runs of timing belts 65.

The arrangement operates in a manner which will now be described. Upon energization of motor 50, small diameter pulley 52 is rotated and, through belt 51, rotates large diameter pulley 48 at a somewhat slower speed. This in turn results in oscillation of link 43 by crank plate 45 through a stroke determined by the adjustment of screws 47 along slots 46. In turn, driving gears 40 are oscillated through a corresponding arc, resulting in oscillation of idler gears 60 through the same are and resulting further in a corresponding reciprocation of the upper and lower runs of timing belts 65 in respective opposite directions. Thereby, shaker table 30 and counterweight 85 are reciprocated in opposite directions and through the same amplitude, so that the horizontal forces are substantially completely balanced out. As a result, shaker can be arranged on any suitable support surface and need not be bolted thereto, as there are substantially no net horizontal forces acting to move the shaker. The speed of operation can be readily adjusted by speed control 12, observing speed indicator 11, and the amplitude of oscillation can be readily adjusted by loosening bolts 47 and sliding crank plate 45 radially inwardly or outwardly along pulley 48, taking note of the indicia 54 on the indicating plate 55 with relation to an edge of crank plate 45 perpendicular to the marked edge of indicator plate 55.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and since certain changes may be made in the above construction without departing from the sphere and scope of the inven-' tion, it is intended that all matter contained in the above description-or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. t

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

What is claimed is:

1. Shaker apparatus comprising, in combination, a support frame; rods carried by said support frame and extending in spaced parallel relation longitudinally of said support frame; a shaker table supported, at longitudinally spaced points, on said rods for rectilinear reciprocation along said rods; a counterweight supported, at longitudinally spaced points, on said rods beneath said shaker table for rectilinear reciprocation along said rods; and driving means interconnecting said shaker table and said counterweight and operable to reciprocate said table and said counterweight longitudinally along said rods in mutually opposite respective directions, whereby, during operation of said shaker apparatus, said counterweight substantially counterbalances the horizontal forces due to rectilinear reciprocation of said shaker table.

2. Shaker apparatus, as claimed in claim 1, in which said driving means comprises endless belt means extending longitudinally of said support frame; and means operable to oscillate said endless belt means through a predetermined amplitude of movement; said shaker table and said counterweight being secured to respective opposite runs of said endless belt means.

3. Shaker apparatus, as claimed in claim 2, in which said endless belt means comprises at least one timing belt trained over and meshing with gears adjacent respective opposite ends of said support frame; said driving means oscillating at least one of said gears through a predetermined arc of angular movement.

4. Shaker apparatus, as claimed in claim 2, in which said endless belt means comprises a pair of laterally spaced endless timing belts extending longitudinally of said frame; a pair of driving gears rotatably mounted adjacent one end of said support frame and meshing with said timing belts; and a pair of idler gears rotatably mounted adjacent the opposite end of said support frame and meshing with said pair of timing belts; said driving means oscillating said driving gears conjointly through a predetermined arc of angular movement.

5. Shaker apparatus, as claimed in claim 4, including means rotatably mounting said idler gears for adjustment toward and away from said driving gears to adjust the slack in said timing belts.

6. Shaker apparatus, as claimed in claim 4, in which said driving means comprises a crank arm secured to a shaft conjointly mounting said driving gears; a link pivotally connected at one end to the free end of said crank arm; a driving pulley; drive means operable to rotate said pulley; a crank plate secured to said pulley; and a pin on said crank plate eccentric to the axis of rotation of said pulley and connected to the opposite end of said link.

7. Shaker apparatus, as claimed in claim 6, including means'mounting said crank plate for adjustment radially of said pulley to adjust the stroke of said crank arm.

8. Shaker apparatus, as claimed in claim 7, including an indicator plate adjacent an edge of said crank plate and containing indicia cooperable with another edge of said crank plate to indicate the stroke of said crank arm.

9. Shaker apparatus, as claimed in claim 4, including an upper bracket having a substantially flat surface overlying the upper runs of said timing belt and a pair of legs depending between said timing belts and apertured to receive bushings engaging said rods; means securing said shaker table to the base of said upper bracket; a lower bracket having a substantially flat base and a pair of upwardly extending legs apertured to receive bushings engaging said rods; and means securing said counterweight to the base of said lower bracket and to the lower runs of said timing belts.

l0. Shaker apparatus, as claimed in claim 9, in which said frame includes a pair of spaced upwardly extending side walls supporting bearings mounting shafts for said driving and idler gears; a pair of cross members extending between said side walls and connected thereto in longitudinally spaced relation to each other; said rods extending through said cross members; and means anchoring each rod to both cross members.

Claims

7. Shaker apparatus, as claimed in claim 6, including means mounting said crank plate for adjustment raDially of said pulley to adjust the stroke of said crank arm.

10. Shaker apparatus, as claimed in claim 9, in which said frame includes a pair of spaced upwardly extending side walls supporting bearings mounting shafts for said driving and idler gears; a pair of cross members extending between said side walls and connected thereto in longitudinally spaced relation to each other; said rods extending through said cross members; and means anchoring each rod to both cross members.