US1741737A - Pivot and bearing - Google Patents

Description

Dec. 31, 1929. H. s. RING PIVOT AND BEARING Filed Nov. 20. 1925- my. a

Patented Dec. 31, 1929 UNITED STATES PATENT OFFICE HARRY S. RING, OI CHICAGO, ILLINOIS PIVOT AND BEARING Application filed November 20, 1925. Serial No. 70,295.

therewith of a curved knife edge, and fur their, in the configuration of the bearing itsel In the disclosure of the invention herein described, reference is made to the use of the invention in the manufacture of scales and weighing devices, butthe application of the principle of the invention and its utility are in no wise limited to these particular articles.

With this preliminary discussion, it is proper to state that the objects of the invention include, among others, the following:

The provision of a curved knife edge and of a curved bearing therefor;

The employment in a bearing for a knife edge or the like of a curved bearing surface, the plane of the curve of the bearing surface being longitudinal with respect to the knife edge of the pivot, if straight, or with respect to the plane of the curve of the knife edge of the pivot, if curved;

A curved pivot edge foruse in a scale or other device, the curvature of such pivot edge providing means for self centering a pivot bearing;

A curved bearing for use in a scale or other device, the curvature of such bearing p'oviding means for self centering a pivot e e- The combination with a curved bearing of a curved knife edge pivot having an inclination providing a self centering effect;

The combinationwith a curved knife edge pivot of a curved bearing therefor having an inclination providing a self centerng effect; and p 7 The combination in a scale bearing of a curved knife edge and a double truncated cone bearing therefor. e

These, and such other objects as may here inafter appear, are obtained by the novel construction, combination and arrangement of the several elements constituting the novel pivot and bearing hereinafter described.

A more or less schematic representation of one form of the invention is made in the accompanying single sheet of drawing, hereby made a part of this application.

In said drawing Figure 1 is an elevation or assembly drawing of a scale employing the invention. Figure 2 is an end elevation of a bracket in which a knife edge or pivot is formed.

Figure 3 is a vertical section on the line 33'of Figure 2. v Figure 4L is an elevation of a hearing which may be used with the pivot illustrated in Figure 2.

Figure 5 is an end view thereof;

Figure 6 is an elevation, schematic in nature, showing a pivot and bearing at an angle of ninety degrees from that shown in Figure 1; and

Figures 7 and 8, respectively, are fragmentary end and side views in elevation of a second form of the invention, the bearing being loose instead of rigid as in Figures 1 to 6 inclusive.

Similar reference characters are used to designate like parts in the drawing and in the description which follows.

For a complete understanding of the general principles of the invention, reference may be had to-all 0f the figures in the drawing. These figures are merely illustrative of forms which the invention may take, and there may be numerous other forms without departing from the spirit of the invention Reference should be had first to Figure 1. This figure is an elevation of a simple scale structure embodying bearings and pivots forming the subject matter of this application. In said scale is a base 10 having a central elevated section 11. Intermediate the elevated section or center support 11 upon which is disposed a beam 12 are bearings and upon these bearings are pivots, said bear.- ings and pivots comprising the subject matter just referred to and providing for the free oscillation of said beam or lever 12.

equally suitable shape.

At each end of the base 10 and mounted thereon for vertical reciprocal movement are two platforms 18. Intermediate the beam 12 and each platform 13 are pivots and bearings embodying the invention as are hereinafter described. Suitable aligning members 1 1 for platforms 13 may be disposed in base 10 as shown.

In the figure just referred to, the pivot part may comprise a metal plate 15, such as is shown in Figures 2 and 3, with suitable means provided whereby such plate may be attached to a lever or beam or other part-as -is-required by the construction employed. Such attachment may be made by screws as" indicated in Figure 2 or by other suitable affixing members. On one end of the plate 1. a circular hole 16 is formed and the edge ,or inner margin 17 of said aperture 16 is a knife edge as is indicated infFigure 3, a vertical section on the line 3-3 of Figure 2.

A pivot, as described, maybe obtained by boring through the plate 15, and by machining the edge of the aperture 16 to provide the knife edge 17 illustrated and described. Said circular knife edge 17 corresponds to and answers the samev purpose as the ordinary straight knife edge found in connection with the conventional straight steelpivots generally employed, but with numerous advantages thereover.

In Figures 4 and 5, a pivot bearing 18 is illustrated. This may be a cylindrical piece of metal turned to the shape shown, that of opposed truncated cones 19, or to any other In Figure 4, a screw end and nut 20 is shown for the, purpose of attaching the bearing 18 to the scale platform or center support as the casemay be.

The knife edge 17 rests upon the arc ofthe surface of said bearing 18 at its least diameter or intermediate, that is, between the two truncated cone sections 19thereof, or the arc of the surface of said bearing 18 at its least diameter or intermediate may rest on the knife edge ,of the pivot, depending on whether the member to which the pivot is affixed is supporting, or being supported by, the member to which the bearing is ailixed. Figure 5 illustrates the end of a bearing 18.

In Figures 1, 6, 7 and 8 the manner in which the improved pivots rest upon or support the unique bearingsjust described and illustrated, is disclosed. In these four figures it is clearly indicated just what the difference is betweenthe present invention and the pivotsand bearmgsheretofore employed in scale structures.

device a curved pivot edge support curved bearings, and

the said pivots and said bearings-have clifferent degrees of curvature. Conventional scale structures call for a straight edge fitted ,as in the case 'facture,

curved pivot or. pivot edges nd P r lel m f 1 upon a bearing straight with respect to the longitudinal aspect of the pivot edge.

It should be instantly apparent that the present invention could be operated with a pivot edge of convex curvature instead of concave curvature as illustrated in the figures in the drawing, and in such case, the bearing would be made concave upon a larger radius than the pivot. The principle of operation in such astructure would be identical with that of the illustrated form, and the results obtained for such structure would correspond with the-results which are obtainable in the illustrated type of the invention.

In order to comprehend the advantages which may be obtained by the scale construcselves, study. of the bearing contact should be had. The surface of the bearing contact is ninimized which, of itself, is an aid to greater accuracy.

fllhere is no end thrust friction on the present pivot as in the ordinary method of scale c struc o A fscale employing the forms of pivots and bearings herein disclosed suffers no loss of accuracy through increased end thrust friction on the pivots if the scale is not set level laterally with respect to the scale lever, utilizing straight edged pivots.

"The necessity for securing parallelism between the edge of the, pivot and its bearing, and parallelism of the pivotedges with re spect to one another, is obviated. This ordinarily necessary parallelism is a difficult object to. obtain in ordinary scale construction.

It is quite manifest thatattaching means different from that shown in Figures 2, and

4 may be employed, and that the bearing may greater latitude in partproportions and assembly is permitted in the course of manuis attained owing to the point of contact between pivot andbearing automatically adjusting itselfto the lowermost ,or uppermost points'of the pivots and bearings, as the case It is a well known matter of fact that after I v .1 mgs and pivots need renewal or replacement,

a scale has been in use for a while the ,bearand these may be easily'renewed in the illustrated device withoutsending the scale back to the'factory as is now'necessary under present methods of pivot and bearing manufacture, owing to the necessity for securing parallelism of ,pivot edges and their be'a in gs the various pivot edges with respect to'one another.

I11 the event ofwear, the piv it [be f 1 30 of ordinary .scale structure and a still greater degree of accuracy may be. For an example .of such a structure the form specifically shown in the drawing or of a like form, may be removed from its support and replaced in a reverse position in order to present a new point of contact to the bearing, if the pivot and bearing is of the form shown in Figures 1, 2, 3, 6, 7, and 8, or of a similar form. The bearing may be revolved a fraction of a turn to present a new point of contact to the pivot. By these adjustments, the necessity for renewing either of these members because of wear may be long deferred.

It is also a well known matter of fact that in the course of ordinary use, parts of a scale, such as the lever or the platforms supporting the weights, may become broken by being dropped or otherwise. In scales employing the pivots and bearings herein disclosed, such broken parts may be easily replaced -without returning the scale to the factory and without specialized skill and knowledge of scales, since there are no straight edgepivots and straight bearings which must be parallelized as in ordinary scale structures; in other words, my device makes interchangeability of parts possible and easy of attainment.

Summarized, the advantages of the present invention comprise, generally, the production of a pivot and bearing insuring greater accuracy, greater simplicity of manufacture, and a greater flexibility of replacement when pivots and bearings become worn, such replacements being readily made and cheaply, and without necessity for returning the scale to the factory.

In Figures 7 and 8, a plate is indicated 25, the aperture therein as 26, and the knife edge as 27. Against the knife edge 27 is a bearing 28 which comprises an inverted U-member, which may have eye ends 29. Projecting between such eye-ends 29 is a bolt 30 which is secured to a bracket or arm 31 forming a portion of the scale part to be supported by or forming a support for the bearing 28, as the case may be.

Such a bearing will center itself upon the pivot and provide a most accurate and sensitive scale. It also possesses all of the advantages hereinabove recited as belonging to the scale described as having a fixed bearing.

An examination of Figures 2 and 3 will make it manifest that the pivot member 15 is adjustable or reversible, to present to the bearing 18 a new contracting surface when the knife edge 17 at thecontacting portion becomes worn.

I'claim 1. The combination comprising a pivot having a circular knife edge projecting interiorly from a support therefor, and a similarly curved bearing disposed within said pivot.

2. The combination described in claim 1, and in which said bearing consists of a pair of cones integrally joined at their small ends to define a circular edge, the knife edge of said pivot engaging said circular edge which serves as a frictionless bearing therefor.

3. In a pivot connection for a scale, a member having an aperture therein, the sldes around the aperture being shaped to form an arcuate knife edge, and an edge curved in the plane of the arcuate knife edge having a greater curvature engaging said knife edge to constitute a bearing therefor.

4. A pivot connection as described in claim 8, and in which the means designed to be inserted through the aperture comprises a member having an arcuate groove therein, the direction of curvature of such groove corresponding with that of the knife edge.

5. In a pivot connection, a flat member having an aperture therein, the side walls of which are shaped to form a circular knife edge, and a bearing having a curved groove confronting said aperture so that said knife edge rests therein, said bearing being rotatable and said flat member being reversible so that the knife edge and bearing are relatively adjustable to each other to change the point of contact therebetween.

HARRY S. RING.

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