US1996627A - Support for machines - Google Patents

Description

April 1935- E. SCHMIERER SUPPORT FOR MACHINES N SK guarantor EUGENE SCHMIERER Filed Sept. so, 1953 RN @N Sum 94 Patented Apr. 2, 1935 UNlTD STAT i a. 'E'

SUPPORT FOR MACHINES Application September 30, 1933, Serial No. 691,626 7' 3 Claims.

My invention relates to supports for machines, such as mixing machines and is more particularly adapted to mixers of the type in which the receptacle for the material to be stirred, mixed, or plasticized is rotated while an upright stirring element is rotated therein in a circle, the relative movement of the receptacle and stirrer being similar to that of a pinion within an internal gear.

My improvements are embodied in a mechanism of such character, in which the hinge means and its associated devices for lowering the mixing element into its working position and for raising it up clear of the receptacle shall be strong and mechanically efficient, simple to operate, free from jar or backlash, permitting the whole ma chine to be compact in construction.

These advantages I attain by a novel arrangement of the lifting gearing, of the housing that surrounds the gears and supplies the bearings for the worm gear shaft, and of the motor-supporting bracket, as well as by a novel balancing and cushioning device for assuring smoothness of operation during the raising and lowering of the mixing elements and associated parts, all being hereinafter described in detail, the essential elements being more particularly pointed out in the appended claims defining my invention.

It is to be understood, however, that the claims are not intended to be limited to the form of the parts illustrated and described further than a limitation to the described form is necessary to distinguish them from the prior art.

Like reference characters indicate like parts in both figures of the drawing. v

Fig. l is a part sectional side elevation of a mixing machine embodying my invention.

Fig. 2 is a part sectional rear view, the section being taken on vertical planes designated by the lines 22 of Fig. 1.

A container l for the material to be mixed is removably seated on a turn table 2, and one or more revolvable mixing elements 3 project downwardly into the receptacle and travel around a circular path in the container during the rotation of the latter, so as to stir, mix or plasticize the material.

The turn table and container are rotated by means of a motor 4 and suitable transmission mechanism contained in the frame 5. This mechanism comprises a drive sprocket 6 on the motor spindle, a, driven sprocket l on the hub 8 of the turn table 2, a drive chain 9 and an idler wheel I i! mounted on a pivoted arm H. The pivot l2 of arm II has aclamping nut [3 for keeping the wheel Iii in any suitably adjusted position. The hub 8 turns on bearings M.

Mixing element 3 is fixed to a disk crank 30. on the spindle of a motor I5. The motor iscarried on a bracket !6 which is fixed to a horizontal rock 5 shaft I! by keys iii. The 'rock shaft is mounted for oscillatory movement in bearings E9 on frame 5. A worm gear is fixed to the middle of shaft ll between the bearings 19, and the bracket l6, which is secured to the shaft by broadly spaced l0 lugs, spans the bearings and the worm gear and the housing in which the latter is contained, as is shown in the left hand half of Fig. 2.

A worm 2i meshes with the worm gear and is fixed on a shaft 22 that can be turned by a hand 15 Wheel 23 or equivalent means. Shaft 22 is supported at one end by a stationary bearing 24, and at the other end by bearings 25 in a bushing 26 carried by frame 5. Thrust bearings 21 on shaft 2 between the ends of worm 2! and the ends 20 of bearings 2% and 25, respectively, keep the worm 2! from moving endwise. The bushing 26 can be withdrawn from the frame along with shaft 22 and Worm 2i for inspection.

A housing encloses the worm andworm gear 25 to permit their thorough lubrication without soiling the machine. The bottom of the housing is a horizontal oil tray or partition 23 and the top 2%; may be a removable cap that fits on the upper half'of worm gear 29.

Turning the hand wheel in one direction rotates the worm and the gear to raise the bracket I5 and motor l5 through the arc of a circle in a vertical plane at right angles to the Worm gear shaft I1. When these parts have thus been raised until their center of gravity passes the vertical, above shaft I'i, they normally tend to drop of their own weight and thereby change the facial engagement of the teeth on the worm and gear from their front faces to their back faces, or 40 vice versa.

I provide a simple and effective means for avoiding the jarring action and the wear that such change of stress would cause by incorporating the following features:

An upright member, such as a rod, or preferably a tube 30, is trunnioned at its lower end to a fixed support, as frame 5. There is a plunger iii in the tube 30 fastened to a plunger rod 32. The rod slides up and down through an abutment member 33 at the top of member 35. Beneath the plunger 3| is a compression spring M and above the plunger is a second compression spring 35. The upper end of rod 32 is pivoted at 36 to a boss 36a that projects from bracket [6 at an appropriate radial distance R from the axis of shaft l1 and between shaft I! and motor l5, so that while the motor is and agitator 3 are being raised from their working position the spring 34 helps the action of the hand wheel 23, by pressing upwardly on plunger 3 i. When the combined center of gravity of the parts being raised is at the top of its arc of travel, which position is indicated by dotted lines, Fig. 1, spring 36 is near its full extension and the upper spring 35 has moved up with plunger 3! through a clearancedistance D and has come into engagement with part 33 and is being put into compression.

Longitudinal movement of bracket [5 and motor i5 rearwardly and downwardly after passing top center causes compression of the top spring 35, thereby maintaining the original relationship of the teeth on gear 2!] and worm 2i, avoiding back-lash.

The springs 3d and 35 can be adjusted by means of thethreaded plunger 3! so as to produce the desired results of balancing the weight of parts IE, IS and 3 during their rise along the arc and while they are descending along it after having passed top center. Pref rably the upper spring 35 is lighter than the lower one 34, and is shorter, as shown in Fig. 2.

When the mixing element 3 is being lowered into the container I by reversed rotation of wheel 23, after the center of gravity has passed the top center, then spring 3 3 prevents the motor l 5 and bracket it from dropping, and the continued pressure of spring 35 keeps the faces of the teeth always in the desired manner just indicated, and avoids all chattering movement of the unit which would otherwise occur if spring 34 were present and spring 35 were absent. The worm and gear are thus kept in proper tooth engagement to produce smoothness and ease of operation of wheel 23.

It is apparent that spring 3 1 normally tends to lift the bracket and motor and that spring 35 tends to sustain the same in their raised position after the center of gravity of the bracket and motor has passed thevertical above shaft H.

The arrangement of shaft 11, and the widely separated bosses on bracket l6 which are keyed at l8 to the shaft prevents side play of motor l5, and the mixing elements 3, when operating on tough sticky materials, and the central location of worm wheel 28 on shaft Il, relatively to bearings 49, all co-operate to keep the worm wheel'accurately in line with worm 26 regardless of all ordinary wear on the working parts.

In the ordinary use of the machine the operation is as follows:

Container l with its charge of material to be worked having been, placed on turn table 2, the

mixing element or elements 3 are lowered into shaft H, but the conjoint action of springs 34 and 35, plunger 3| and pivotal connection 36 on bracket It keeps the teeth of worm gear 20 in substantially uniform engagement with the threads of worm 2|, and always in the same sense, so that notwithstanding the normal tendency for the pressure engagement to change from, say, the front faces of their teeth to the back faces, or vice versa, there is in the device no such change, and no back-lash or gear jar is produced.

After mixing is finished, the hand wheel 23 is turned in the opposite direction and the motor i5 is raised, as indicated by the dotted line position, until shoulder Hib comes to rest on abutment 5b. This movement also is without any jar or back lash.

While mixing, there is no sidewise play in the main joint, because its construction, already described, presents widely spaced supports for housing it on shaft ll, widely separated bearings 9 for the shaft itself, and central location of worm gear 28- on the shaft ll. Ample gear lubrication is provided by the chamber defined by partition 23 and the gear housing 29. The mixers 3 can be raised or lowered while they are in rotation, if desired.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In a machine support comprising a frame and a liftable machine-supportingbracket hinged thereto, in combination, a worm gear fixed to said bracket co-axially with the hinge, a worm mounted on said frame so as to operably engage the worm gear, means for rotating the worm, a rod pivoted to the bracket at a place intermediate the hinge and the motor and carrying a plunger, an abutment member, a spring member adapted to press against the plunger and normally tending to lift the bracket and the motor, and a second spring member adapted to be compressed between the plunger and said abutment member after the center of gravity of the bracket and the parts carried thereby has passed the vertical above said hinge during a lifting movement of said bracket.

-2. A structure as set forth in claim 1 wherein the plunger is movably mounted lengthwise of the rod and adapted for effecting changes in the relative working tensions of said springs.

3. In a machine support comprising a frame, a liftable machine-supporting bracket and a hinge member connecting the frame and bracket, said hinge member including a rock shaft supported in broadly spaced bearings on the frame, the bracket being fixed to the shaft at points outside of said bearings, a closed housing carried by the frame, a worm gear fixed to said shaft inside the housing, a worm operably engaging the gear, a shaft carrying the worm and means for rotating the same, a bushing removably secured inthe housing and having bearings for said shaft, and means for controlling the direction of tooth engagement between the worm and gear during,

their operation, said means comprising a rod pivoted to said bracket intermediate the motor and the rock shaft, a plunger member on the rod, a spring adapted to normally urge the plunger in a direction tending to'lift the bracket and motor, and a second spring tending to sustain the same in their raised position after the center of gravity of the bracket and motor has passed the vertical above said hinge.

' EUGENE SCHMIERER.

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