US2703655A - Latch tripping device - Google Patents

Description

2 Shets-Sheet 1 INVENTOR March 8, 1955 H. w. sANFoRD LATCH TRIPPING DEVICE Filed May 2, 1950 March 8, 1955 H. lW. SANFORD LATCH TRIPPING DEVICE 2 Sheets-Sheet 2 Filed May 2, 1950 INVENTOR W Sanfafd ATTORNEY United States Patent O LATCH TRIPPING DEVICE Hugh W. Sanford, Knoxville, Tenn.

Application May 2, 1950, Serial No. 159,457

6 Claims. (Cl. 214-58) This application is a continuation-in-part of my prior applications, Serial No. 571,170, tiled January 5, 1945, now Patent No. 2,674,383, granted April 6, 1954, and Serial No. 739,795, tiled April 7, 1947, now Patent No. 2,634,007, granted April 7, 1953.

This invention relates to improvements in Latch Tripping Devices, of the character used for controlling the release of drop bottom doors of conveyances, such as mine cars.

This is an improvement on the latch tripping mechanism set forth in my prior patent, No. 2,399,708, granted May 7, 1946. In the prior device, the latch tripping mechanism was operated by a lug on a side sill of the car, which would require the lug to be disposed laterally of the latch hook which supports the door, and causes a somewhat more complex apparatus to be required than is desired.

One object of this invention is to simplify and improve the construction of the latch tripping device and the manner in which it is operated automatically by the car, by providing for the operation of the tripping device directly by one of the doors, such as a lug on the bottom of the latched door. This provides for bringing the controlling means very close to the point where the latch hook is located, often remote from the side sills of the car, in closer` relationship to the latch hook. Furthermore, if the rear end-sill structure should droop, or when the wheel treads should wear, causing the latch hook to be lowered closer to the top of the rails, the rear door will be lowered correspondingly, and the relationship between the tripping means and the hook will not be changed ap- The operation of the latch tripping device directly by the latched door itself not only provides a much simpler and less expensive mechanism that is more practical to manufacture, but also makes possible the supporting of the door by two laterally spaced hooks which can be brought fairly close together on the longitudinal axis of the car, directly behind the central bumper of the endsill structure. Then if one of the latch hooks should fail to latch, the other hook will be in a more central position and will support the load on the door nearer to its center line, without as much danger of bending of the door plate due to the weight on the unsupported edge thereof. Moreover, if the edge of the door should become bent or warped, the variation in the height of the latch engaging elements on the door above the rail would be more nearly the same on such a bent door than it would be if these elements were spaced farther apart transversely.

Another object of the invention is to provide for a more positive release of the latch hook by an arm which will jerk the hook out from under the free edge of the door, which tripping arm is operated positively by a lever arm operated by engagement with a lug or projection on the bottom of the door. The tripping arm is pivotally supported so that it will swing down out of tripping position in a direction toward the front of the car. Such an arm will be lowered very rapidly after releasing the latch, so there will be no tendency whatsoever for it to touch the end sill structure, even though the car be running at very high speed. However, if the end sill structure should contact the tripping arm, it would have the effect merely of forcing the arm down out of the path of the car, without danger to the tripping mechanism.

Gil

Patented Mar. 8, 1955 ice Still another object of the invention is to provide greater llexibility between the operating parts of the tripping mechanism by yieldable connection therebetween, such yieldable means not only acting on the tripping means but also yieldable means acting on the lever arm. The yieldable means acting on the lever arm allows for variations in the height of the door above the track and also permits bodily movement of the lever arm when the car passes over the tripping mechanism in reverse direction and the lever arm thereby contacts the door or the pad thereon.

According to a preferred embodiment of the invention, provision is made for latching the drop bottom door or doors of the conveyance by means of a latch hook which engages the rear edge of the latched door, and which hook preferably is disposed above the lower edge of the end sill, as described in my patent, No. 2,399,708, as well as above the lower edge of the door. A tripping arm is mounted in the trackway in position to be raised into engagement with the latch hook -in properly timed relation with the movement of the car or conveyance over the tripping device. This operation of the tripping arm preferably is accomplished by means of a lever arm operatively connected with the tripping arm and disposed in close relation therewith, in position to be operated directly by the latched door itself. It is preferred that the operation of the lever arm be accomplished by means of a pad provided on the bottom of the door plate. The proportioning of the lever arm and tripping arm may be such as to raise the tripping arm into position for engagement with the latch hook, as the car or conveyance passes over the tripping device.

It is preferred that the tripping arm be pivotally mounted in the trackway for swinging movement toward the front of the car or conveyance and engage the latch by a jerk-out action so as to pull the latch to a released position as the conveyance passes over the tripping device. A lever mounted in the trackway has a yieldable connection with the tripping arm to provide for relative motion therebetween. A shoe on the lever is also yieldably supported in position for engaging a pad on the door to operate the tripping arm as the car passes over the tripping device. This shoe is thus held up in position for engaging the pad, but the yieldable support thereof allows for variations in the height of the door, as Well as accommodating for reverse movement of the conveyance over the tripping device.

The invention is illustrated in one embodiment in the accompanying drawings, in which:

Fig. 1 is a side elevation of a drop bottom mine car howing the improved form of latch tripping device there- Fig. 2 is an enlarged longitudinal vertical sectional View thereof;

Fig. 3 is a cross section on the line 3--3 in Fig. 2; and

Fig. 4 is a similar view on the line 4--4 in Fig. 2.

This invention is shown as applied to a mine car of the general type set forth in my prior patent, No. 2,001,471, granted May 14, 1935, adapted for conveying coal or other loose lading from a receiving point to a tipple or other point of discharge. The mine car is shown to be of the 4-wheel type, having three drop bottom doors interconnected for release in one-two-three order. This application of the invention is used, however, merely for purpose of illustration, and it is evident that the subject-matter of this invention may be applied to other types of cars, vehicles, and drop bottom conveyors in general, wherever it may be desirable to release bottom doors for dropping, in which the principles of this invention may be applicable.

The general structure of the car illustrated comprises a car body formed of side and end walls 1 and 2 rigidly secured together, the side walls 1 rising from a pair of oppositely disposed side sills 3, connected together at the ends of the car by means of combined end-sills and bumpers, designated generally at 4. The side and endwhich is a bottom opening designated generally at 5 (Fig. 3) for discharge of the lading therethrough.

The car is supported upon wheels 6 and axles 7 connected with the side sills 3. The wheels 6 are adapted to travel on a track formed by a pair of laterally spaced rails indicated generally at R.

Each of the doors 8, 9 and 10, usually is pivotally supported or hinged at its forward edge, capable of downward swinging movement at the point of discharge or tipple for discharge of the lading. Each of the forward or middle doors supports the free edge of the next forward door in the construction usually employed heretofore in the art, while the rear edge of the rearward door is adapted to be latched, and, when released, will allow successive or simultaneous dropping of the doors, according to the character of mountings used for the doors, various forms of which are well-known and have been used in the art.

In the form of door supporting mechanism shown in my prior patent, No. 2,001,471, three drop bottom doors were illustrated and adapted for discharge in onetwo-three order from front to rear of the car, the pivotal mountings for the middle and rear doors permitting bodily slidable movement thereof, Then upon release of the rearward door, it may drop sufficiently to drag and move bodily rearward, thereby releasing the free edge of the middle door which will likewise drop and release the free edge of the forward door. This occurs usually just before the car reaches the tipple or bin, and permits dropping of the forward door in the bin for discharge of the lading thereon, as soon as room enough is provided in the bin therebeneath. The other doors drop in succession during the continued forward movement of the car over the bin or tipple in one-twothree order from front to rear of the car.

After dumping in passing over the bin or tipple, the doors are adapted to be closed by the usual door-closing rails located in the track. The doors are thus moved successively about their hinge rods to their closed positions, and the middle and rearward doors are pushed forward into wedging relation with the next forward door, adapted to be latched in closed position.

As shown in Figs. 2 to 4, provision is made for latching the free edge of the rearward door 10 in closed position, thereby holding the several doors closed, to retain the lading in the car until the latching means is released for dumping. For this purpose, I have pro vided on the free edge of the rearward door 10, one or more supporting trunnions 14, one for each latch of said door. I prefer to use a pair of latches. each designated generally by the numeral and spaced apart as indicated in Fig. 2, symmetrically with respect to tg? loggitudinal center plane of the car, designated P Each of the latches 15 is provided with an engaging notch 16 in the forward face thereof, as hereinafter described more in detail. The latches 15 are pivotally mounted on a cross shaft 17 supported by brackets or plates 18 secured to the adjacent end wall 2 of the car. Each of the latches 15 is preferably so constructed, or spring-pressed at 22, as to be disposed normally in its door-supporting position', or to return thereto automatically when disengaged for release of the lading.

Each of the latches 15 is provided with a seat 19 (Fig. 2) at the forward face thereof in position to receive the end of the adjacent trunnion 14 attached to the free edge of the rearward door 10. As shown in Fig. 2, the seat 19 is located on the opposite side of the vertical plane passing through the pivot axis of the latch 15 from the door 10, so that the Weight of the' door and the lading thereon tend to maintain the latched relation without any tendency for this weight to push the latch to one side. This is particularly true when a concave seat is engaged by a convex end of the trunnion, whereby any movement of the latch tending to release the door must raise up the free edge of the door.

The latches 15 are interposed between the free edge of the rearward door 10 and the adjacent end sill structure 4, underneath a guard plate 27, secured to the adjacent end wall 2, and which guard plate is supported also on the top edges of the mounting plates or brackets 18.

The latches 15 are so constructed and ,arranged that they are disposed wholly above the lower edges of the end-sills of the car, and also, preferably, above the lower face of the rearward door, in protected positions. This prevents disarrangement of the latches or damage thereto in the event of wreckage of the car or from contact with obstructions in the trackway, as might occur in a mine, thus assuring adequate protection of the latches to maintain these in proper operative positions. Each latch 15 is so mounted in protected position between the door 10 and the bumper 4 that a tripping space is provided between said door and the latch 15 in latched position for entry of a tripping arm therebetween.

The tripping mechanism for the latches 15 is adapted for mounting in the trackway between the opposite rails R at a point adjacent the bin or other point of dumping. This tripping mechanism may be attached to the rails R or supported thereby or otherwise in the trackway.

In the form illustrated, the tripping mechanism is shown as mounted on a supporting plate 28, rigidly secured at opposite edges thereof to the track rails R. This plate 28 is reinforced by bars welded on the surface thereof.

Where two latch hooks are provided spaced on opposite sides of the longitudinal upright central plane of the car, a tripping device may be provided, if desired, for each such latch hook, or both hooks may be operated by a single tripping device. It is preferred, however, that separate tripping devices be used. Each such tripping device may be of the form shown in Figs. 2 to 4, which illustrate one form of this invention.

In this form as illustrated, bearing boxes 30 are secured upon the mounting plate 28 in a longitudinally spaced relation, and journaled therein is a mounting pin 31. As shown in Fig. 4, the mounting pins 31 are separate and in axial alignment on opposite sides of the upright central plane of the conveyance, although one mounting shaft may be used for both tripping arms, if desired, having a single actuating lever therefor.

A tripping arm is shown at 32 mounted on each pin 31, a separate tripping arm being shown for each latch 15. This tripping arm 32 extends upwardly forwardly of the trackway, as shown in Fig. 2, and has an engaging hook 33 in the upper end portion thereof, in position to engage in the notch 16 in the latch. The engaging hook 33 is shown as having substantially a wedgeshaped end to be deected by the lower end of the latch after releasing the latter from the door.

A separate mounting shaft is shown at 34 journaled in bearings 35 on the supporting plate 28. This shaft is shown as extending from side to side for operation by one lever arm of the tripping devices for both latches.

Fixed rigidly on the shaft 34 is a connecting arm 36, one for each tripping arm 32 and extending from the shaft 34 to a position beside the tripping arm. The connecting arm 36 is connected yieldably with the tripping arm 32 by a coiled spring 37 interposed between spring seats 38 and 39 on the arms 32 and 36 respectively. A bolt 40 passes through the spring and seats to hold the same in alignment.

The upward travel of the tripping arm 32 is adapted to be limited by an adjusting bolt 41 threaded through the mounting plate 28 in position to engage a lug 42 or a side of the arm 32. The bolt 41 may be adjusted to vary the upper limit of the arm 32.

The connecting arm 36 carries a lug 43 on a side thereof having an adjusting bolt 44 passing therethrough. The lower end of the bolt 44 projects in position to engage an arm 45 on a bell-crank lever 46, journaled on the shaft 34. The other arm 47 of the bell-crank lever 46 extends upwardly, as shown in Fig. 2.

A contact member comprising a shoe 48 is sleeved loosely over the arm 47, slidably thereon, with an interposed spring 49 between the shoe 48 and the arm. The spring 49 normally urges the shoe upward but will yield for downward movement of the shoe thereon to accommodate an abnormally low part of the conveyance or in the event of movement of the conveyance in a backward direction over the tripping device. A connecting bolt 50 between the shoe and lever 46 limits the movement of the shoe relative thereto.

The upper end of the shoe 48 preferably is beveled at 51 in position to engage a pad 52 welded on the under face of the door or otherwise secured thereto. The pad 52 has a long inclined forward lower edge portion 53 and a short beveled rearward lower edge portion 54 to facilitate engagement with the beveled end 51 of the shoe 48.

Normally the shoe 48 is held in an upright position by the weight of the tripping arm 32 pressing downward on the connecting arm 36, in part counterbalanced by a weighted arm 55 fixed to the shaft 34.

Normally the tripping arm 32 is in lowered position, as shown in dotted lines in Fig. 2, with the lever arm shoe 48 upstanding in the path of the pad 52.

As the conveyance passes over the tripping device in the forward direction indicated by the arrow in Fig. l, the inclined face S3 of the pad 52 will strike lthe beveled end S1 of the shoe 48. This will rock the shoe counterclockwise in Fig. 2 suiciently to allow the pad S2 to pass over the shoe.

Such rocking movement of the shoe 48 will swing the lever 46, causing the arm 45 thereof to press upward on the connecting arm 36 thereby raising the outer end of the latter. This movement of the ,connecting arm 36 will be transmitted through the spring 37 to push upward on the tripping arm 32, moving Ythe latter to the full-line position in Fig. 2. This will occur as the way is cleared over the tripping arm, the hook 33 of which will be raised into the path of the latch 15. The length of the bottom face of the pad 52 is sufficient to hold the hook 33 up until it engages in the notch 16 and moves the latch to the released position shown in dotted lines in Fig. 2.

Then the end of the shoe 48 will drop off the back end of the pad 52, releasing the pressure on the connecting arm 36, which thereby releases the holding action on the tripping arm 32, allowing the latter to drop by gravity. This action occurs before the end sill strikes the tripping arm and allows the latter to fall out of the path of the end sill. However, the forwardly swinging tripping arm is so mounted that, if it should be hit by the end sill, such engagement would merely knock the arm downward without causing damage to the device.

The spring connection 37 provides a lost-motion connection between the actuating lever and the tripping arm. The spring 49 also provides a yieldable support for the shoe 48. In the event of movement of the conveyance in the reverse direction over the tripping device, the beveled face 54 of the pad 52 would engage the upper end of the shoe 48, pressing the latter downward against the tension of the spring 49 to allow the pad to pass thereover. The two springs cooperate to provide the desired yieldability for a flexible tripping device.

The operation of the tripping device by a pad on the bottom of the doors enables the latches to be brought in closer toward the center of the car, and is more readily adaptable to cars of different lengths.

While the invention has been illustrated and described in one embodiment, it is recognized that variations and changes may be made therein lWithout departing from the invention as specified in the claims.

I claim:

l. In conveying mechanism, the combination with a trackway, a dumping conveyance movable along the trackway and having a drop bottom door and latch means for holding the door closed and movable to release the door for opening, said latch means being mounted on the conveyance for movement lengthwise thereof and having an actuating portion with a notch in the forward face thereof, of tripping mechanism mounted at the trackway and including a tripping member, means mounting the tripping member in the trackway for upward swinging movement, said tripping member being mounted on said means for lowering movement in a direction toward the forward end of the conveyance, a contact member, lever means operatively connecting the contact member with the tripping member, means forming yieldable lostmotion connections between the contact member and the lever means and between the lever means and the tripping member, and means on the conveyance in position to engage the contact member for operating the latter to move the-tripping member into latch engaging position.

2. In conveying mechanism, the combination with a trackway, a dumping conveyance movable along the trackway and having a drop bottom door and latch means for holding the door closed and movable to release the door for opening, said latch means being mounted on the conveyance for movement lengthwise thereof and having an actuating portion with a notch in the forward face thereof, of tripping mechanism mounted at the trackway and including a tripping member, means mounting the tripping member in the trackway for upward swinging movement, said tripping member being mounted on said means for lowering movement in a direction toward the forward end of the conveyance, a pivoted lever member, a shoe slidably mounted on the lever member, a spring interposed between the lever member and the shoe normally urging the shoe to extended position relative to the f lever member, a connecting arm connected with the lever member, means forming a yieldable lost-motion connection between said connecting arm and the tripping member, and a pad fixed to the bottom of the door in position to engage the shoe to cause movement of the tripping member into operative engagement with the latch means.

3. In conveying mechanism, including a trackway adapted to receive a dumping conveyance thereon having a drop bottom door and latch means for holding the door closed, the combination of tripping mechanism adapted to be mounted at the trackway and including a tripping member, means mounting the tripping member for upward swinging movement to engage the latch means and for lowering movement in a direction forwardly of the trackway, an upright contact member adapted for engagement by means on the conveyance, lever means operatively connecting the contact member with the tripping member, and means forming a lost-motion yieldable connection between said lever means and the contact member, and means forming a lost-motion yieldable -connection between said lever means and the tripping member.

4. In conveying mechanism, including a trackway adapted to receive a dumping conveyance thereon having a drop bottom door and latch means for holding the door closed, the combination of tripping mechanism mounted at the trackway and including a tripping member, means mounting the tripping member for upward swinging movement to engage the latch means and for lowering movement in a direction forwardly of the trackway, an upright contact member adapted for engagement by means on the conveyance, a pivoted lever having the contact member slidably mounted thereon, a coiled spring interposed between the pivoted lever and the contact member, a connecting arm, means operatively connecting the pivoted lever with the connecting arm, and a lost-motion spring connection between said connecting arm and the tripping arm.

5. In conveying mechanism, including a trackway adapted to receive a dumping conveyance thereon having a drop bottom door and latch means for holding the door closed, the combination of tripping mechanism mounted at the trackway and including a tripping member, means mounting the tripping member for upward swinging movement to engage the latch means and for lowering movement in a direction forwardly of the trackway, an upright contact member adapted for engagement by means on the conveyance, a pivoted lever having the contact member slidably mounted thereon, a

l coiled spring interposed between the pivoted lever and the contact member, a connecting arm, means operatively connecting the pivoted lever with the connecting arm, a coiled Spring interposed between the connecting arm and the tripping arm, and adjustable stop means for limiting the movement of the tripping arm in an upward direction.

6. A latch tripping device adapted to control the release of a drop bottom door supported by latch means on a dumping conveyance, comprising a tripping member adapted to engage and release the latch means, means mounting the tripping member for upward swinging movement in one direction, a lever arm extending toward the tripping member, means forming a resilient connection between one end of the lever arm and the tripping member, a pivotal support for the opposite end of the lever arm for upward swinging movement of the latter in the opposite direction from the tripping member, an actuated member operatively connected with the lever arm, and a resilient support for the actuated member yieldably holding the latter in position for engagement 2,225,463 with a portion of the conveyance for actuation thereby. 2,399,708 2,441,978

References Cited in the ie of this patent 2,487,447

UNITED STATES PATENTS Jones Feb. 23, 1915 8 Rose Dec. 17, 1940 Sanford May 7, 1946 Sanford May 25, 1948 Kepner Nov. 8, 1949 Sanford July 14, 1953

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