US 2243690 A
Description (OCR text may contain errors)
May 27, 1941.
B. S. WATLING WEIGHING SCALE Filed April 12, 1939 Patented May 27, 1941 WEIGHING SCALE Burns S. Watling, Chicago, 11]., assignor to Watling Scale Company, a corporation of Illinois Application April 12, 1939, Serial No. 267,461
This invention relates to upright weighing scales and has reference more particularly to scales of the general type disclosed in Letters Patent to T. W. B. Watling, No. 1,289,060, December 24, 1918; No 1,702,582, February 19, 1929; No. 1,785,849, December 23, 1930'; and No. 1,923,.- 287, August 22, 1933. In the scales shown in the above noted patents, the weight on the scale platform is counter-balanced through a mechanism comprising a system of levers underlying and actuated by the platform, an upwardly extending rod that is drawn downwardly by the weight, a yoke on the upper end of said rod framing and actuating a dash pot, a cross bar pivotally mounted on the upper end of the yoke, a pair of straps connected at their lower ends to the ends of the cross bar and at their upper ends connected to pivoted sector cams, from which cams two pendulum weights are suspended and swing outwardly when a weight is placed on the platform and inwardly when the weight is removed from the platform.
Some difficulty has heretofore been experienced in that part of the weight transmission mechanism from the platform to the pendulum weights which consists of the pivoted cross bar and the straps connecting the ends of the latter to the sector cams; and the general object of the present invention is to improve this part of the transmission with a view to greater sensitiveness, simplification of structure, durability, longevity and freedom from liability of breakage.
The invention resides in an improved structure of and mounting for the cross bar designed to aflord greater sensitiveness and reduce friction. prevent any lateral play of the cross bar on its bearing, and facilitate the engagement of the lower ends of the straps with the ends of the cross bar.
An illustrative embodiment of the invention is shown in the accompanying drawing, in which-- Fig. 1 is a front elevation of the scale.
Fig. 2 is a rear elevation of the weight-actuated parts in the upper portion of the scale.
Fig, 3 is a detail elevation, broken out between its ends, of one of the straps.
Fig. 4 is a longitudinal vertical section through the cross bar to which the lower ends of the straps are detachably connected.
Fig. 5 is a vertical section on the line 5-5 of Fig. 4.
The casing of the scale comprises a base I 0, an upright housing portion H, and an upper covering portion or cap l2. The scale platform I3 is connected through a system of levers (not shown) underlying the platform to a weight operated rod l4 having a yoke I5 attached to its upper end. A cross bar designated as a whole by I6 pivoted to the upper end of the yoke l5 engages the lower ends of a pair of ribbon-like metal straps such as ll which extend over and are detachably secured to sector cams l8 that are pivoted at IS on a cross frame 29 and carry pendulum weights 2! mounted on rods 22 secured in the hubs of the cams l8, which weights swing outwardly to counterbalance the weight placed upon the scale platform l3. Mounted on the bearing support of the cross bar i5 is a vertical rack bar 23 which operates a pinion 24 fast on the arbor of a weight-indicating scale disc 25 indicated by dotted lines in Fig. 1.
The parts above described are all broadly disclosed in the above noted T. W. B. Watling patents, and my present improvements have to do with novel and improved structural features of the cross bar l6 and its mounting.
The strap which I prefer to use for connecting the ends of the cross-bar It to the sector cams I8 consists of a single length of thin, flat, flexible metal ribbon H, the upper and lower end portions of which are folded over as shown at 26 and 21 and soldered or spot welded to the body of the strap. In folding the upper end portion a small round loop 28 is formed at the bend, and this receives a wire link connector member consisting of an eye 29 and integral opposed bent legs 3!], the lower horizontal portions of which enter and pivot in the loop 28 in the plane of the strap. A similar loop 3| is formed at the bend on the lower end of the strap, into which is entered one limb of a rectangular wire link connector 32, which pivots in the plane of the strap. A screw stud 33 (Fig. 2) passed through the eye 29 and into the periphery of the sector cam I8 secures the upper end of the strap I1 to the cam.
Describing now the structural details of the cross-bar I6 and its mounting, on the upper end of the yoke I5 is a forked lug 34. in and between V the limbs of which is a pivot stud 35 that, as
shown in Fig. 5, may consist of a machine screw passed through one limb of the lug and threaded into the other. Mounted on the stud 35 is the inner ring 36 of a ball bearing, and encircling the latter is the outer ring 31; the opposed surfaces of the rings being formed with the usual raceways for the ring of balls 38. Centrally of the outer surface of the outer bearing ring 31 is a circular circumferential rib 39 (Fig. 5). Overlying the upper half of the ring 31 is a semi-circular member 4!], continuous with the ends of which are oppositely extending radial arms 4! of equal lengths terminating in integral inverted U-shaped hooks 42. Underlying the lower half of the ring 37 is a semi-circular member :33, complemental to the member 45, continuous with the ends of which are short oppositely extending radial arms 44 that are secured to the arms ll by rivets 45. outwardly pressed hollow semi-circular ribs 40 and 43 on the members 46 and 43 interfi't with the rib 39 to look the central ring member of the cross-bar against any lateral shift on the bearing ring 3?. This central ring member, consisting of the connected semi-circular rings 40 and 4-3, forms in efiect a central ringshaped hub of the cross-bar.
In applying the straps to the improved crossbar, the eyes 29 are first engaged with the screw studs 33 on the peripheries of the sector cams, and the links 32 are then engaged with the hooks 42 of the cross-bar in the manner clearly evident from Fig. l; or this order of engagement may be reversed. In either case, the engagement of the straps with the sector cams and the cross-bar is very simply and easily effected, and manifestly no twisting or warping of the strap is involved in entering the links 32 on, or removing them from, the hooks 42, or during the operation of the counter-balancing mechanism. The pivoted links on the upper and lower ends of the strap reduce the degree of bending at the strap ends and thus increase the durability and longevity of the strap. The described structure and anti-friction mounting of the cross-arm prevents any edgewise play of the straps during operation, and affords a high degree of strength, durability and sensitiveness of balance in the cross-arm.
1. In a counter-balance actuating mechanism for weighing scales of the type described, a piv- J oted cross-bar for connectin a platform-actuated yoke to a pair of counter-balance weightaotuating straps consisting of a ring-shaped hub aaeaeeo made in a plurality of arcuate sections connected together, a bearing member on which said hub is mounted, a pivot stud on which said bearing member is mounted, arms of equal lengths continuous with one section of said hub extending radially from opposite sides of said hub, and inverted U-shaped hooks on the free ends of said arms for engagement with the lower ends of said straps.
2. In a counter-balance actuating mechanism for weighing scales of the type described, a pivoted cross-bar for connecting a platform-actuated yoke to a pair of counter--balance weightactuating straps consisting of a ring-shaped hub made in two complemental semi-circular sections connected together, an anti-friction bearin member on which said hub is mounted, a pivot stud on which said bearing member is mounted, means for preventing relative lateral shift of said hub and bearing member, arms continuous with one section of said hub extending radially from opposite sides of said hub, and inverted U- shaped hooks on the free ends of said arms for engagement with the lower ends of said straps.
3. In a counter-balance actuating mechanism for weighing scales 01 the type described, a pivoted cross-bar for connecting a platform-actuated yoke to a pair of counter-balance weightactuating straps consisting of a ringshaped hub made in two complemental semi-circular sections connected together, an anti-friction bearing member on which said hub is mounted, said hub and bearing member formed with interfitting parts locking them against relative lateral displacement, a pivot stud on which said bearing member is mounted, arms of equal lengths continuous with one section of said hub extending radially from opposite sides of said hub, and inverted U-shaped hooks on the free ends of said arms for engagement with the lower ends of said straps.
BURNS S. WATLING.