US1879923A - Drive mechanism - Google Patents

Description

86131227, 1932. Dag- 1,879,923

I DRIVE MECHANISM 7 Filed Feb. 24, 1931- 2 Sheets-Sheet 1 Sept. 27, 1932. E, DE|$TER I 1,879,923

DRIVE MECHANISM Filed Feb. 24. 19:51 2 Sheets- Sheet 2 I Patented 27, 1932 "PATENT OFFICE UNITED STATES- mnn'n. mnsrna, or roar wanm', nmrnm, assrenon 'ro narsrna momma co, or

' roar WAYNE, nmmna Application am: February 24,1981. Serial No. 517,730.

This invention relates generally to a drive mechanism, and more particular y to a belt or chain drive, wherein there is relative movebnent between the driving and driven memers.

Obviously, where a belt-or chain drive connection is employed between two, members having relative-movement, the belt or chain alternately loosens and tightens, resulting in considerable slipping, which causes excessive stretch or wear, this being arti'cularly true on short center drives, as or instance in vibratory screens, wherein the driving member is stationary and the driven member is mounted upon the vibratory element.

While the invention may be applied to numerous types of machines, the same has been designed particularly for use in connection with vibratory screens; Therefore, for the purpose of ex lanation only, the invention is shown and escribed in connection with a machine of this type.

The invention has primarily for its object to provide means, in a chain or belt drive,

to com ensate for relative movement between the driving and driven elements, and thus maintain substantially uniform tension upon the driving connection, thereby eliminating flapping with resulting stretch or wear upon the connection. Incidentall a fnore specific ob'ect resides 'Zin eccentrics. y mounting one o the drive elements so that as relative movement occurs, the same is automatically compensated for and substantially uniform tension maintained on the driving connection.

More particularly in connection with drives for vibratory screens, a specific object of the invention resides in the culiar setting of the eccentric drive mem er with relation to the means for imparting vibratory action to the screen.

With the above and other objects in view, which will appear as the description Iproceeds, the invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and moreparticularly defined by the appended claims, it being understood that such changes in the precise-embodiment of the herein disclosed invention may be made as come within the scope of the claims.

In the accompanying drawings is illustrated one complete example'of the physical embodiment of the present invention constructed according ,to the'best mode so far devised for the practical application of the princi les thereof;

In t e drawings, Figure 1 is an elevation of a vibratory screen with the invention applied thereto; 7

Figure 2 is an enlarged longitudinal section through the driven vibrating mechanism, taken on the line 22 of Figure 1;-

Figures 3 to 5 are transverse sections, as indigated by the corresponding lines on Figure Referring now more particularly to the accompanying drawings, wherein the invention is illustratedin connection with 9. vibrating screen, the numeral 1 designates a base adapted to be supported upon any suitable. foundation at approximately the angle illustrated. Mounted on the .base are the spaced spring seats 2 for reception of the coil springs 3, which in turn support the spring seats 4 secured to the side frames 5' of the vibratin screen section, the screen 6 being indicate by dotted lines.

The structure thus far described is conventional and therefore forms no specific part of the present invention, other than as set forth in the combination hereinafter claimed, and as set forth in the preceding objects the in vention has "numerous applications, and therefore the same is not to be limited to the specific combination shown;'

. Secured on the shaft 12, preferably adja cent the bearings 11, are a pair of overbalanced weighted wheels 13, each formed in two sectional i and 15 for the purpose of'regulat.

ing the vibratory action, as will be hereinafter explained; I

As best shown in Figures 2 and 3, the section 14 comprises a rimmed wheel having its hub 16 kc ed upon the shaft 12 and locked in assemblsd position by the locking screw 17. The wheel 14 is overbalancedby the weighted portion 18 confined to a limited circumference of the wheel.

Asbest shown in Figure 2, the key which splines the wheel 14 to the shaft 12 projects s 'ghtly beyond the hub 16 for engagement with t e hub 19 of the section 15, it bein noted inFigure 4 that the hub 19 is provider with a plurality of keyways 19, which allow relative adjustment between the sections 14 and 15, for the purpose of regulating vibratory action'of the screen.

The wheel is also provided with I an overbalanced weighted portion 20 and is locked against longitudinal movement on the shaft 12 by means of the set screw 21.

Naturally, when the weighted portions 18 and 20 are aligned, maximum vibration Wlll be imparted to the screen as the wheels are rotated, the overbalanced weight of the wheels being greatest in this position. Should it be desired to reduce the amount of vibratory movement, the wheel 15 may be shlfted to the desired position wherein the effect of the weighted portion 20 will offset that of the weighted portion 18 in the wheel 14.

In the operation of vibrating screens of the type heretofore describedfiit is necessary to rotate the overbalanced w eels at a high rate-of speed, and due to the free resilientmounting of the-screen, haturall vibratory movement will be imparted to t e same.

In the resent instance, the screen section will have both a longitudinal oscillatm and rocking movement. Centrally of its en s, the

screen frame will naturally follow a sub-.

stantiall circular path as the result of the action 0 the overbalanced wheels 14 and 15. However, inasmuch as the ends of the screen frame are opposed by the springs 3, a rock1 n movement-1s im arted to the screen, whic results in the ends being vibrated'through an elliptical path, as dia ammatlcally' illustrated in Figure 1 by t e arrows appearing thereon.

'In order to impart rotative movement to the shaft 12, at pulley 22 is secured thereon intermediate the overbalanced wheels by means of the set screws 23 which provide for ready adjustment ofthe pulley on the shaft.

In the present form 0 the invention, the pulley is provided with a plurality of V- shaped grooves 24 for reception of the belts 25 connected with the motor pulley 26. However, it is to be understood that the invention is eqpally applicable to any type of chain or be t drive.

i V i 7 As best shown in Figures 2 and 5, the'pulley 22 is eccentrically mountedupon the shaft 12,

the eccentric portion being so' disposed with relation to the vibratory action of the screen as to compensate for relative movement between the shaft 12 and the motor pulley 25, thus providing substantially uniform tension upon the belts 25, which eliminates slippage all? also resultant stretch and wear upon the One would naturally assume that the high spot of the eccentric pulley 22 should be oppositely positioned withrelation to the overbalanced portions of the wheels 14 and 15. However, it has been found in the operation of vibrating screens, such as illustrated, that there is a lag or delay in transmitting the inertia of the overbalanced portions of thewheels 14 and 15 to the vibrating screen section, this lag comprising substantially a half a revolution of the overbalanced wheels. Consequently, in order to compensate for the relative movement between the pulleys 22 and 26, the high spot of the eccentric pulley 22 is substantially aligned with the over-.

balanced portions of the wheels 14 and 15. Therefore, although the weighted portions of the overbalanced wheels may lead the move- -ment of the screen by approximately half a revolution, the pulley 22 is so set with relation to the true movement of the screen as to compensate for the relative movement between the pulley 22 and the pulley 26.

It will also be appreciated that while either the driving or driven pulley may be offset to accomplish the result sought, it is considered more desirable to offset the movable driven pulley, inasmuch as a high spot of the pulley can thenbe definitely set with relation to its true relative movement. This is particularly true in a belt drive where a slippage occurs, which would result in disalignment of the eccentric driving pulley with relation to the driven element.

' From the foregoing explanation taken in connection with the accompanying drawings, it will be quite apparent that exceedingly simple and eflicient means has been provided for insuring substantially uniform tension upon either a chain or belt drive, in which re ative movement occurs between the driving and driven pulleys or sprockets.

It will be further understood that in using the term pulley throughout the specification said screen for imparting vibratory move-' ment thereto, said mechanism comprising a transverse over-balanced shaft; an eccentric pulley mounted on said shaft for rotating the same, a transverse stationary drive shaft, a concentric pulley mounted'on said drive emme shaft in the same lane with said eccentiic pulley, and an en ess belt connecting hoth of said pulleys. 2.111 a driving mechanism for vihreting h screens including a, mechanism mounted on seid'screen for imparting vihretory movement thereto, said mechanism comprising 1e horizontal over-bala noed shaft; an eccentric pulley mounted on said shaft for rotating to the same, the high part of said eccentric puliey being substantially elined with the overhelenced side of said shaft, e horizontelstetionai-y drive shaft, a concentric pulley mounted on said drive shaft in the same verticei plane with said eccentric ulley, and anindless connection between hot of said puieys. {In testimony that I-claim the foregoing I e have hereunto set my hand at Fort Wayne,

00 in the county of-Allen and State of Indiana.

EMIL E. DEISTER.

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