US738336A - Automatic weighing apparatus. - Google Patents

Description

. 1 PATENTED SEPT. s, 1903. A. R. LEITGH & T. A. DRUMMOND. AUTOMATIC WEIGHING APPARATUS.

APPLIUATION FILED JUNE 30, 1902.

1 I'LV6/Lib/4S WilffttiljeS I UNITED STATES- Patented September 8, 1903.

PATENT OFFICE.

ALFRED RAVSON LEITCH AND THOMAS ALEXANDER DRUMMOND, OF \VINNIPEG, CANADA.

AUTOMATIC WEIGHING APPARATUS.

SPECIFICATION forming part of Letters Patent N 0. 738,336, dated September 8, 1903.

Application filed June so, 1902.

To all whom it may concern.

Be it known that we, ALFRED RAWSON LErroH and THOMAS ALEXANDER DRUM- MOND, of the city of Winnipeg, in the Province of Manitoba, Canada, have invented certain new and useful Improvements in Automatic Weighing Apparatus, of which the following is a specification.

The object of our invention is to devise means for accurately weighing grain as it comes from the thresher; and it consists, essentially, of a weighing-bucket carried by a counterbalanced lever pivoted on a stationary part at one side of the bucket and releasably supported at the other by one arm of a scale-beam, a supply-spout above the bucket, means for closing the said spout when the bucket drops with a charge of predetermined weight, a door in the bottom of the bucket, means for normally holding the door closed, means for releasing the door when the bucket drops, and means for closing the door of the bucket and opening the supply-spout when the bucket resumes its normal position.

Our invention further comprises certain details of construction, as hereinafter more specifically described and then definitely claimed.

The drawing is a side elevation, partly in section, of our apparatus, showing the weighbucket in its receiving position.

Our apparatus is intended especially for use in connection with threshing-machinesto indicate the quantity of grain threshed. Hence we show it in connection with a grainelevator A and a bagger B.

The elevator A is of ordinary construction,

and any form of bagger may be employed.

screwed upon a threaded spindle for this pur- $erial No- 113,792. (No model-J pose. Of course it will be understood that the lever F is forked or divided to pass on each side of the elevator-spout and the bucket. the counterbalancing-weight is bent downwardly to a point belowthe pivot b and is provided witha knife-edge dog H, which rests I. This knife-edge dog is pivoted on the le-' ver at d with a rule-joint and is normally held in the position shown by means of the bent spring 6. The scale-beam l is pivoted on the frame of the apparatus at f, and its long arm is provided with the weight J. This scale-beam is also provided with an adjusting-weight K of ordinary form.

The bottom of the bucket D is provided with a door L, hinged at g. The opposite or is otherwise adapted to engage the springactuated latches M, set one at each side of the bucket. Each latch has a tail 2' formed thereon, which is adapted when the bucket drops, as hereinafter described, to strike the trip N, secured to the frame of the machine, and thus cause the latch to release the door.

As we find that grain is discharged by the buckets of the elevator with such velocity that it would strike the top of the laterallyextending spout and thence fiy into the bucket with snificient force to destroy the accuracy of the weighing, we find it necessary to insert in the spout just above the opening a deflector 0. While this deflector might be fixed, we prefer to pivot it atj and to secure to the pivot the arm P, provided with a suitable clamping-nut, by means of which it may desired position.. This deflector may be so set that grain striking it is deflected to the lower side of the spout, from whence it rolls by gravity into the bucket with its velocity destroyed. The bottom edge of the deflector is preferably lipped, as shown at o, to prevent the grain sliding off it with too great Velocity. At this point it will be advisable to describe in part at least the operation of the invention. When the elevator is in operation,grain flows through the spout G into on the short arm of the Z-shaped scale-beam.

be clamped to the slotted quadrant 7c in any The opposite endof the lever to I edge of the door has a bar h secured thereto the bucket. As soon as a sufficient quantity of grain has entered the bucket to overcome the balancing power of the weight J the bucket falls slightly, and the knife-edge dog H slips off the short arm of the scale-beam. The bucket then falls freely until the lever F comes into contact with the frame of the apparatus or preferably with a stop -bar Q, adjustably secured to the frame by the setscrews Z. Before this has occurred the tails of the latches M have struck the trips N, releasing the door L, which is thrown open by the weight of the grain in the bucket. The bucket is returned to its normal position by the counterbalancing-weight G, the knifeedge dog H rocking in its pivot to permit it to assume its original position above the short arm of the scale-beam.

In order to return the door L to its normal position, we provide a coil-spring B, one end of which is secured to the door, as shown, theother to the bucket, preferably by an adjustable slot and clamping-nut connection m, as shown. This spring is so connected that when the door is closed the line of draft of the spring is on the inside of the hinge g and when the door is open on the outside, so that it tends to retain the door in the position in which it happens to be at any particular time either open or closed. It is necessary, therefore, to provide means for starting the door on its closing motion until such time as the draft of the spring comes within the hinge. We therefore provide the door with a curved spring-arm S, which when frame of the apparatus in such a position that when all the grain has escaped the pressure exerted on it by the spring-arm is sufficient to give the door the impetus desired. The door is then rapidly closed by the spring and locked by the latches M. It is necessary, however, to cut off the supply of grain while the bucket is falling and rising, and We therefore provide the opening of the spout C with the half-doors T, which are provided at each side with arms U, preferably pivoted on a common pivot o. On these arms we pivot the upper ends of the links V, their lower ends being pivoted together at p. The arms E, on which the bucket is pivoted, are extendedupwardly and slotted to embrace the pivots p, the position of the slots being such that each pivot lies normally close to but not quite in engagement-with the upper end of the slot.

A coil-spring W is secured to the arms U in sucha position that it will change its lines of draft in' a manner similar to the spring R. The result of the slotted connection between the pivots p and the arms E is that the bucket drops sufficiently to release the knife-edge dog H from the short arm of the scale-beam before the bucket exercises any pull on the links V, thus adding materially in securing accurate weighing. By the time the bucket has moved thus far it draws on the links and closes the doors sufficiently to bring the line of draft of the coil-spring W below the pivots 0, when its tension immediately causes the half-doors to snap shut in the position shown in Fig. 2. It will of course be understood that though this operation takes some time to describe its action in reality is very rapid, so that hardly any grain at all falls into the bucket after the weight of material has become sufficient to tip the scale-beam. When the bucket rises after discharging its contents, the slots in the arms E permit it to almost resume its normal position before pressure is brought on the pivots p to start the half-doors on their opening movement. As soon as the line of draft of the coil-spring R is brought above the pivots 0 it opens the half-doors as rapidly as they were previously closed, permitting the grain to once more flow into the bucket.

The features of our invention which are most important in securing accurate weighing are, first, the construction of the lever F, so that its point of engagementwith the scalebeam is considerably below the pivot c. This enables the knife-edge dog to rapidly clear the short end of the scale-arm as soon as it starts in motion. The second point is the shape of the scale-beam, so that the weight J is considerably above the pivot Z).

The third point is the arrangement of' the half-doors for rapidly closing and opening the opening of the supply-spout. The fourth point is the arrangement of the deflector O to prevent the impact of the grain from spoiling the accuracy of the weighing. In addition to these features, which, as we have said, are of importance in insuring accuracy, We consider the arrangement for opening and closing the door at the bottom of the bucket simple, effective, and reliable.

The apparatus shown is so proportioned that the counterbalancing-weight exerts an upward pressure of seven pounds on the bucket. This is found ample to secure the proper return of the bucket after its contents have been discharged. When wheat is be ing weighed,we use a forty-siX-ounce weight on the scale-beam, as with that weight a halfbushel of Wheat is weighed at every operation of the bucket. With oats or other grain the weight hung on the scale-beam would of course require to be changed. We find in practice that our apparatus is accurate, with a limit of error of only a half-ounce.

Although the apparatus is especially designed for use with threshing-machines, it may also be employed for weighing any other material of granular or substantially granu- This insures delicacy of action in thescale-beam.,

lar form such as tea, sugar, coffee, and fiourunder various conditions.

What we claim as our invention is 1. In automatic weighing apparatus the combination of a counterbalanced piv-oted lever having one end lower than the other; a pivoted scale-beam having one arm adapted close to one end to engage the low end of the lever to maintain it in its normal position; a weigh-bucket secured to the lever between its pivot and its supported end; a door in the bottom of the bucket; means for holding the door closed'when the bucket is in its receiving position; means for releasing the door when the bucket drops with a charge of predetermined weight suflicient to disengage the lever from the scale-beam; means for closing the door after the contents of the bucket are discharged; a supply-spout for the bucket; and means operated by the falling and rising of the bucket for closing the said spout when the bucket drops and for opening it when the bucket rises, substantially as described.

2. In automatic weighing apparatus the combination of a counterbalanced pivoted lever having one end lower than the other, a pivoted scale-beam having one arm adapted close to one end to engage the low end of the lever to maintain it in its normal position and its weightarm normally above the pivot; a weigh-bucket secured to the lever between its pivot and its supported end; a door in the bottom of the bucket; means for holding the door closed when the bucket is in its receiving position; means. for releasing the door when the bucket drops with a charge of predetermined weightsuflicient to disengage the lever from the scale-beam; means for closing the door after the contents of the bucket are discharged; a supply-spout for the bucket; and means operated by the falling and rising of the bucket for closing the said spout when the bucket drops and for opening it when the bucket rises, substantially as described.

3. In automatic weighing apparatus the combination of a counterbalanced pivoted lever having one end lower than the pivot; a pivoted scale-beam having one arm adapted close to one end to engage the low end of the lever to maintain it in its normal position; and a weigh-bucket secured to the lever between its pivot and the supported end, substantially as described.

4. In automatic weighing apparatus the combination of a counterbalanced pivoted lever having one end lower than the pivot; a pivoted scale-beam having one arm adapted close to one end to engage the low end of the lever to maintain it in its normal position, and its weight-arm normally above the pivot; and a weigh-bucket secured to the lever between its pivot and the supported end, substantially as described.

5. In automatic weighing apparatus the combination with the vertically movable weigh-bucket and weighing mechanism, of an elevator; a laterally-extending spout communicating with the upper part of the elevator and having an opening therein above the bucket; and a deflector adjustablyhinged at its upper edge located above the opening so as to deflect any material striking it against the bottom of the spout, a lip being formed at its lower edge, substantially as described.

6. In automatic weighing apparatus the combination with the vertically movable weigh-bucket and weighing mechanism, of an elevator; alaterally-extcnding spout communicating withthe upper part of the elevator and having an opening therein above the bucket; and an adjustable deflector located above the opening so as to deflect any material striking it against the lower side of the spout above the bottom, substantially as described.

7. In automatic weighing apparatus the combination with a vertically-movable weighbucket and weighing mechanism, of a supply-spout provided with an opening above the bucket; two half-doors provided with arms pivoted on a common center so that the doors may be swung back to leave the opening clear or brought together to close it; a coil tension-spring secured to the said arms so that it lies on one side of the pivot-point when the doors are open and on the other side when they are closed; and a loose connection between the arms and a part moving vertically with the bucket for starting the open- Y ing and closing movements of the doors, substantially as described.

S. In automatic weighing apparatus the combination with a vertically-movable weighbuoket and weighing mechanism, of a supply-spout provided with an opening above the bucket; two half-doors provided with arms pivoted on a common center so that the doors may be swung back to leave the opening clear or brought together to close it; a coil tension-spring secured to the said arms so that it' lies on one side of the pivot-pin when the doors are open and on the other side when they are closed; links pivoted on the arms at their upper ends and pivoted together at their lower ends; and an arm moving vertically with the bucket and slotted to embrace the common pivot-pin of the links, the said pin normally lying close to the upper end of the slot, substantially as described.

9. In automatic weighing apparatus the combination of a counterbalanced pivoted lever having one end lower than the pivot; a knife-edge dog pivoted at the low end of the lever by a rule-point; a spring tending to retain the dog in its normal position; a pivoted scale-beam with one arm of which the said dog normally engages close to the end; and a weigh-bucket secured to the lever between its pivot and the dog, substantially as described.

ing; and a lip on the bottom edge of the de- "o flector, substantially as described.

W'inuipeg, Manitoba, June 21, 1902.

ALFRED RAWSON LEITCIL THOMAS ALEXANDER DRUMMOND.

In presence of '1. G. MATHERS, L. HARTSHORNE.

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