US1748351A - Scale - Google Patents

Description

L. JAENICHEN Feb. 25, 1930.

SCALE Filed May 19, 1926 INVENTOR.

ATTORNEY.

Patented Feb. 25, 1930 UNITED STATES PATENT OFFICE LOUIS JAENICHEN, OF SPRINGFIELD TOWNSHIP, OAKLAND COUNTY, MICHIGAN, AS-

SIGNOR TO THE STANDARD COMPUTING SCALE COMPANY, OF DETROIT, MICHIGAN,

A CORPORATION OF MICHIGAN SCALE Application filed May 19,

The present invention relates to scales and particularly to computing platform scales. Heretofore computing platform scales of the compound lever type have been more or less inaccurate due to the difliculty of so constructing the scale that the platform in its movement under the load would remain parallel to itself. This has been neutralized in one known type of scale by so constructing the levers, springs etc., that the platform has very little movement and the indicator pinion accordingly made very small. Such a construction is open to the objection that the parts must be very accurately made and some 'of the parts consequently more or less delicate.

The present invention has among its obj ects to overcome these objections and provide a scale-0f this type in which the platform may have a considerable movement and remain substantially parallel to itself throughout and consequently the indicator parts may be made sufiiciently large to stand rough usage and not require extremely accurate workmanship, yet the scale Will be accurate in its operation.

Other objects will readily appear to those skilled in the art upon reference to the following description and drawing in which Fig. 1 is a side elevation of the working parts of the scale.

Fig. 2 is an end el vation thereof from the right of Fig. 1.

Fig. 3 is a diagrammatic illustration of the action of certain parts of the mechanism. 5 In the drawings, the lever housing is shown at 10 with an upright casing 11 at one end thereof.

The platform 12 is provided with legs 13 and 14 extending down into the housing 10 and resting on the main levers 15 and secondary levers 16 respective. The main levers 15 are pivoted upon the arms 17 secured to housing 10 and extend to the rear of the latter to a point under casing 11 where their face ends are supported by springs 18. The latter extend upward into the casing 11 and are attached at their upper ends to an equalizing bar 19 supported pivotally upon an adjustable stud 20 carried in an arm 21 forming part of casing 11. Springs 18 are connected to mainv 1926. Serial No. 110,162.

levers 15 close to the ends of the latter through suitable knife edge pivots 22.

Secondary levers 16 are supported, by means of suitable knife edge pivots 25, at one end by the main levers 15 through links 26 and at their other ent s by links 27 which latter extend up through casing 11 to near the extreme upper end thereof where they are provi led with eyes 28 adapted to hook over the hooks 29 formed within the casing head.

The extreme end of one of the levers 15 has secured thereto a rod 35 provided at its upper end with a rack 36 adapted to. coact with a pinion 37 carried upon a rotatable shaft 38 to which is secured a pointer 39 in front of a dial lO provided with suitable indications.

In the operation of the scale, it should be noted that, as the legs 13 and 14 are fixed rigidly to the platform 12, and, as leg 13 on its pivot moves on the arc of a circle having its center at the pivot on arm 17, the lower end of leg 1 must move laterally a short distance with leg 13. Consequently, lever 16 must move longitudinally whenever the platform 12 moves vertically. For this reason, lever 16 must be supported on links permitting such movement.

However, in scales of this type as usually constructed, lever 16 is supported upon two links of about the length of link 26, the one at the rear end of the lever being swung from the housing. This arrangement, on account of the angular movement of the latter link and its short radius, say for example about two inches, causes an upward movement of its end of lever 16, thereby opposing the downward mov ment of the platform. This action therefore seriously interferes with the accuracy of the scale. It also tends to bind the pivot.

In the present construction, link 27 is constructed of such length that the are through which its lower end swings it so flat as to be to intents and purposes a horizontal line and the downward movement of platform 12 is not opposed to any noticeable degree by the relative upward movement of lever 16.

The arcs referred to are shown in comparison in Fig. 3. In this figure the are A represents the travel of the lower end of the known link and the arc B that of link 27. These arcs are somewhat longer than those actually travelled but it will be noted that while the vertical distance of the ends of arc B from a true horizontal line is hardly detectable, the vertical distance of the ends of are A from the horizontal is approximately an m eighth of an inch.

ow having described the invention and the preferred form of embodiment thereof it is to be noted that the said invention is not to be limited to the s cific details herein set forth but only by tle scope of the claims which follow.

I claim 1. In a compound lever platform scale having an upright casing at one end of the platform housing, a main lever, a secondary lever supported at one end upon said main lever and at its other end by a link extending up into and supported by said upright casing.

2. In a compound lever platform scale having an upright casing at one end of the platform housing, a main lever, and a secondary lever supporting the platform, said secondary lever being supported at one end by said main lever, and means for supporting the other end of said secondary lever said means being of suflicient length and so arranged as to ermit longitudinal movement of said sec? ary lever in a substantially horizontal pat 85 3. In a compound lever platform scale having an upright casing at one end of the platform housing, a main lever, and a secondary lever supporting the platform,. said secondary lever being supported at one end by said main lever, and means for supportin the other end of said secondary lever sai means being adapted to permit longitudinal movement of said secondary lever 1n a substantially horizontal path, said means consisting of a link pivotally connected to said secondary lever and supported from the top of said upright casing.

LOUIS JAENICHEN.

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