US376042A - Hamlin paddock - Google Patents

Description

(No Modl.)

H. PADDOOK.

PLATFORM WEIGHING SCALE.

No. 376,042. Patented Jan. 3, 1888.

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UNITED STATES PATENT OFFICE.

HAMLIN PADDOCK, OF ST. J OHNSBURY, VERMONT, ASSIGNOR TO THE E. & T. FAIRBANKS 8?; COMPANY, OF SAME PLACE.

PLATFORM WEIGHlNG-SCALE.

SPECIFICATION forming part of Letters Patent No. 376,042, dated January 3, I888. Application filed January 26, 1886. Serial No. 189,805. (No model.)

. To all whom it may concern:

Be it known that I, HAMLIN PADDOOK, a citizen of the United States, residing at St. Johnsbury, Caledonia county, Vermont, (assignor to the E. & T. FAIRBANKS & COMPANY, of same place,) have invented certain new and useful Improvements in Platform-Scales, of which the following is a specification.

My improvement applies to the bearings or feet of the platform-frame, which rest upon the pivots of the underlying levers at the four points or corners; and the objects of my invention are, first, to make these feet or bearings self-adjusting, so that an equal, true, or

level bearing at the four points will be assured, and, second, to cushion the bearings so that the pivots will not be injured by the shock of my invention further consists in cushionsprings introduced between the said bearings and the platform-feet, as hereinafter fully set forth.

In the drawings annexed, Figure 1 presents a longitudinal sectionof a platform'scale provided with my improvements. Fig. 2 is an inverted plan view of the platform-frame with my improved bearings. Fig. 3 is an enlarged fragmentary longitudinal section of one of the feet of the platform fitted with my improved self adjustable and cushioned bearing, and Fig. 4 isa cross-section thereof. Fig. 5 is a view similar to Fig. 3, showing the platform forced down by a heavy weight and the cushion-springs compressed. Referring to Fig. 1, a indicates the platformcasingorfixed frame of the scales, and b indicates the frame of the platform.

' c 0 indicate the underlying levers,whicl1 are pivoted and hung in the fulcrum-loops d from the under side of the fixed frame, in the usual manner,which forms no part of my invention. The platform-frame I), as seen best in Fig. 2, is preferably made of cast-iron, and is formed as usual with four feet, 9, at the respective corners, which project therefrom on the under side over and opposite the usual pivots, ff, of the levers c 0. Now, the pivotsff of the levers are of course made very hard to resist wear and insure accuracy, and the feet of the platform,which rest thereon, must also be correspondingl y hard for the same reasons. It is usual to make the feet of chilled iron, or to fit them with a piece of hardened steel cast into the feet; and in either case, where the feet are made solid and non-self-adjusting, it is necessary that the faces or bearings of the four feet be nicely fitted and made true or parallel with one another, so that they may bear alike upon the four pivots of the levers.

A self-adjusting foot or bearing has sometimes been made of chilled cast-iron or of castiron, with a piece of hardened steel inserted, which foot is fastened to the platform by a pin and allowed to move freely thereon and thus adjust itself to the pivot. The chilled-iron bearing is, however, objectionable on account of its uneven structure and the presence of cracks and seams in its surface, which render it difficult to have them smooth and true. The objection to the steel bearing cast in the foot is that the pieces must be first fitted and then cast in and afterward hardened,which is difficult. Now, in my improvement I provide the feet with selfadjusting hardened-steel bearings in a very simple and efficient manner, as will nowappear-that is, referring to the drawings, I interpose between the foot y and the pivots f a rocking steel bearing, h, preferably made in half-round or semi-cylindrical form,with its round side bearing against the base of the foot and its fiat side resting on the pivot. The bearings h extend, of course, transversely to the pivots f, and are about the same length as the feet 9, and each end of the hearing is supported and held in small socksecu ed to the ends of the feet 9. These caps have ateral flanges l, which overlap and embrace\the ends of the feet g, and are secured ets (ilrecesses in recessed caps i 13, which are thereto by the bolts 70, and are thus firmly and simply attached to the feet and at the same time firmly support and retain the bearings and allow the same a free rocking or self-adjusting motion on the feet, as will be readily understood from Figs. 3, 4, and 5. Hence'each bearing will adapt itself accurately to its own pivot and thus insure a true and level hearing at each of the four pivots at each corner of the platform, so that the bearings will thus adjust themselves to any position the platform may take, whether tipped sidewise or lengthwise or moved forward or back within any of the limits of motion allowed to the platform,which is a most desirable result in the construction of scales. It will now be seen that my improved bearing is not only easily made, but is readily applied to or removed from the foot by simply removing the caps i, so that the bearings are easily put in place at first or may be easily removed and renewed afterward if repairs are required, which are important advantages. It will be further seen that the form of my bearing and the fact of its being made loose or distinct from the foot, allows the bearings to be made or cut in proper lengths from bar-steel of half-round section, which may be then hardened and finished, and quantities'of the bearings may be made in this way at once, any one of which will fit any platform, thus rendering the construction very simple and accurate, and enabling the bearings to be made uniform and interchangeable, so that all scales may be fitted alike, while any scale can be repaired with new bearings in a perfect and simple manner whenever required. The self adjusting or rocking bearings may abut directly against the metallic feet 9 of the platform-frame; but I generally prefer to interpose between the same some form of elastic cushion, preferably in the shape of two rubber spring-blocks or cushions, m m, which are let into recesses in the base of the platformfeet, and which normally project sufiicient to bear upon the round side of the hearing and project it a slight distance from the foot, as seen best in Figs. 3 and 4, so that normally the weight of the platform rests elastically on the springs m, and not rigidly and directly on the metallic bearings and their lever-pivots, as is usual. It will hence be seen that when the platform receives the shock of any suddenly-applied weight or strain, or even when any weight is placed gradually on the platform, the springs m at will be compressed, as seen in Fig. 5, allowing the weight or strain to bear gradually or elastically on the bearings h and thepivots f, and if the weight is very great the springs will be compressed sufficient to allow the feet to bear firmly on the bearings h h; but in no case will the weight, whether gradual or sudden, be borne suddenly or rigidly by the bearings and pivots, as heretofore, and hence the delicate knife-edges of the pivots, on which the accuracy of the scale depends, will be guarded effectually against the injury to which ordinary scales are so liable from heavy weights falling on the platform, and which frequently ruin new scales. It will be further seen that these springsm not only effectually guard the pivots from shock and injury, but enable the rocking bearings to better adjust themselves to the position of the pivots, and serve to hold the bearings in firm position free from shakiness, and yet free to elastically adapt themselves to true positions relatively to their respective pivots.

Heretofore, in order to guard the pivots of scales against shocks, it has been usual to make the platform in two layers, with a pack ing of rubber between the two, or a drop-lever is used to drop the levers down to allow the platform to rest upon the fixed frame while the load is being placed thereon, the levers and platform being afterward raised to weigh the load; but both of these methods have objections which are entirely overcome by the simple and effective means which I employ. The cushions m on may be made of any other suitable elastic material besides rubber, but preferably of solid rubber blocks or of metallic spiral springs. Again, the recessed caps t i may be made in one piece for each foot instead of being separate, or the bearings h-h may be socketed on the platform feet in any equivalent way, so as to be capable of a free rocking motion without departing from the principle of my invention.

What I claim as my invention is 1. Inaplatform-scale, the combination,with the platform and the underlying levers and lever-pivots, of a self-adjusting bearing between the platform aud lever-pivots made of hardened steel in the form of a semi-cylindrical bar, substantially as set forth.

2. In a platform-scale, the combination,with the platform and the underlying levers and lever-pivots, of half-round or semi-cylindrical hardened bearings introduced between the platform and thelever-pivots,arranged transverse to the pivot with their flat side resting on the pivots and their convex side toward the platform and free to rock and adapt themselves to the position of the pivots, substantially as herein shown and described.

8. In a platform-scale,the combination,with the main levers and lever pivots and the overlying platform provided with the feet 9, of the rocking self-adjusting bearings h h, interposed between the feet and the knife-edge pivots, and means for holding said bearings at each end on the feet so that the bearings are free to rock, substantially as and for the purpose set forth.

4. In a platform-scale, the combination of the main levers and the overlying platform having the feet 9 with the rocking bearings h h and the removable socket-caps t 2', substantially as shown and described.

5. The combination, with the main levers and the platform I), of the feet 9, having sockets in the base thereof, rocking bearings h,

"placed under said feet,and springs m, arranged bearings h h, arranged and operating snbstanin and protruding from said sockets against tially as shown and described. said bearings, substantially as shown and de- Scribei HAMLIN PADDOCK. 5 6. The combination, in a platform-scale, of Witnesses:

the platform b, having feet g, with the caps 73 P. D. BLODGETT,

t, the cushion-springs m m, and self-adjusting H. E. BLODGETT.

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