US2647724A - Hoist structure - Google Patents

Description

1953' J. R.- COFFING 2,647,724

HOIST STRUCTURE .Filed April 21, 1951 3 Sheets-Sheet 1 Aug. 4, 1953 3 Sheets-Sheet 2 Filed April 21, 1951 1953 J. R. COFFING 2,647,724

HOIST STRUCTURE Filed April 21, 1951 3 Sheets-Sheet 3 mmv TOR.

. BY firms if. [9/7276 Patented Aug". 4, 1953 UNITED STATES PATENT OFFICE HOIST STRUCTURE James R. Coffing, Danville, Ill. Application April 21, 1951, Serial No. 222,257

7 Claims. 1

This invention relates t a hoist structure of the ratchet type which is capable of load raising, controlled load lowering and free running action, reference being made to my application for Letters Patent Serial No. 129,071, filed November 23, 1949.

It is the object of this invention to provide a simplified hoist having a reversely biased holding pawl manually controlled to bias said pawl to ratchetengaging position during load raising, and normally bias it out of ratchet engagement while permitting it to be positively moved into ratchet engagement during load lowering. This is accomplished through the medium of a control ring in camming engagement with said pawl such as to normally permit free ratcheting action, but forcibly move it against spring tension into ratchet engagement upon completion of a load lowering stroke.

This invention further provides for latching the load pawl out of ratchet engagement during its return stroke of the load lowering operation through the medium of said control ring, with a manually adjustable pin operable to unlatch said pawl into ratchet engagement at the beginning of a lowering operation, when in one position, .and cause it to remain latched for reversing the handle position, when in another position. A further feature of the invention resides in the manual biasing of the holding pawl out of ratchet engagement and camming the load pawl out of ratchet engagement by the control ring to permit of free camming action.

The full nature of the invention will be understood from theaccompanying drawings and the following description and claims:

Fig. 1 is a side elevation of the hoist structure embodying my invention.

Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1.

Fig. 3 is a detail sectional view taken on the line 33 of Fig. 2}

In the drawings I have illustrated a hoist structure which comprises a modification of the invention disclosed in my copending application, Serial No. 129,071,,filed November 23, 1949, wherein there is provided a housing 63 having the usual swivel supporting hook 64. This housing 83 has mounted therein a rotatable load wheel 69 carrying a shaft 65, which has one end supported in an ofiset bearing 66 forming a part of the housing. Intermediate of its ends the shaft 65 is supported on a face plate 61 of the housing, and projects a considerable distance beyond the face plate for carrying the ratchet wheel 68. That portion of the shaft mounted within the housins,

2 which housing is open on its lower side, carries the load wheel 69 over which is adapted to pass a hoist chain 10.

Mounted on the front face of the plate 87 is a holding pawl 1|, which is adapted to engage the teeth of the ratchet wheel 68 for the purpose of holding the same against reverse rotation. This holding pawl is pivotally mounted on a supporting pin 12, which is mounted in a recess in a lug 13 extending from the front face of the plate 61. The holding pawl is biased in engaging position through the means of a coiled spring 14 wrapped around the pin 12 and having one end bearingonone end of a pin 15 extending through the pawl H, see Fig. 2. The opposite end 16 of this spring is fastened in a pin 71 on a rotatable head 18. The head is mounted upon a shaft 19, which extends through the housing and carries at its opposite end an adjusting handle 89 see Fig. 1. The head 18 is provided with an extension 8! having an offset lug 82 (Fig. 2). The extension 8|, when the head is rotated in one direction, engages a stop 83 to prevent further rotation thereof; and when the head 18 is rotated in an opposite direction, the offset portion 82 engages against the end 16 of the spring, thereby providing a stop for the head 18 in the opposite direction.

With the head 18 and its pin 11 in the position illustrated in Fig. 2 the spring has a biasing effect on the holding pawl H to bias the pawl into engagement with the teeth of the ratchet 68. However, if the head 18 is rotated in a counterclockwise direction, the pin 11 is rotated over center to a position where the portion 82 bears against the spring, and the spring will be effective to bias the holding pawl H out of engagement with the teeth of the ratchet 68. Under normal loading raising conditions, the head is rotated clockwise to occupy the position illustrated in Fig. 2, which is the position to cause the spring to bias the pawl into engaging position. As a result, as the shaft and. with it the ratchet wheel 68 is rotated counterclockwise, in the load raising direction, the holding pawl will ratchet over the teeth to permit this rotation; but at the same time will drop into position to lock the ratchet wheel 68 and its shaft 65 against clockwise rotation.

Rotatably mounted on that portion of the shaft 65 which extends beyond the ratchet wheel is an operating handle 84, see .Fig. 1. This handle is provided with a housing or hub portion 85 having a bearing 86 to accommodate the end of the shaft 65. The handle has mounted within the housing an operating load pawl 81 pivoted upon a pivot pin 88, see Fig. 2, extending between the two side walls of the housing 85. This load pawl 81 is adapted to cooperate with the teeth of the ratchet wheel 68 for controlling the rotation of the shaft 65, and with it the load wheel. The load pawl is biased in its engaging direction through the medium of a spring 89, one end of which is hooked over the back side of the pawl. A portion of the spring 89 is wound around a stationary pin 99 fixedly secured between the walls of the handle housing portion. In addition to the load pawl 81 there is mounted on the hub portion otally mounted on a pin 9| fixedly secured in one wall of the hub portion. The latch 9| is provideo with a pin receiving latchin notch 92. Under predetermined conditions a pin 94 on the load pawl 81 engages in notch 92 and maintains the load pawl in non-operating condition. The pawl-controlling latch 9| is biased in a direction to cause the latching notch92 to engage and hold the pin 94 through the medium ofthe end 95 of the coiled spring 89, which end is adapted to engage over a pin 96 in the faced the latch 9 I.

Adjacent the face of the ratchet wheel 68, see Fig. 2, is a control ring 91 which is provided with a radially extending arm '98 slotted as at 99 to receive a projection of'the pin 15 on the holding pawl 1|. This arm 98 has a camming face I82 adapted, under predetermined conditions, to engage a pin I94 on the face of the load pawl 81. This ring is also provided, at'a point opposite the arm 98, with a second arm I95 likewise, under predetermined conditions, adapted to be engaged by the pin I94 on load pawl 81;

Extending through the housing'63' is a transversely movable pin I96, see Fig. 3, the end I91 of which is, under normal operation, adapted to lie in the path of the latch 9|. This pin I86, however, may be moved transverselythrough the medium of an operating handle I08 so that the end I91 is withdrawnfrom the path of the latch 9|. The head I08, see Fig. 3, is shouldered as at I89 to, bypartially rotating the pin, engage over the face of the shoulder'portion I 190i the. housing to retain the pin 106 inits retracted position against the influence of a biasing spring III, which normally biases the pin in a position to project its end I81 in its normal or projected path. 1

In normal operation, and for the purpose. of description, the hoisting operation may be considered as the normal operation of'the hoist, with the spring control head 18 rotatedto the position illustrated in Fig. 2, the coiled spring 14 is in a position to bias the holding pawl 1I into engagement with the. teeth of the ratchet 98. Likewise, the spring portion 89 will normally bias the load pawl 81 in a direction to engage the teeth of the ratchet 68:. Accordingly, with a. load on the hoisting chain, the holding pawl in engagement with the ratchet 69 will hold the-shaft 65, and with it the load wheel, against clockwise rotation under the load. By elevating the handle, the pawl 81 will ratchet over the handle has reached near the upperm limit of its. stroke. At this. tim as; soon as the d wnstroke of the handle is effected, the pawl 81 will engage the ratchet teeth rotating he ratch wheel and the load wheel in a counterclockwise direction causing the chain to operate to hoist the load. As soon as. the handle has. moved downward to thelimit of its; normal Operating stroke, the pawl 1|. engaging the ratchet 6.8 will the wheel 58 until 85 a pawl controlling latch 9| pivethe spring 14 under hold the ratchet against rotation in a clockwise direction, accordingly holding the load from dropping. The handle 84 may be raised for another stroke, the pawl 81 ratcheting over the teeth until the handle reaches the uppermost part of its stroke. The latch 9|, on the downward stroke of the handle, will engage the projection I01 and, accordingly, will be thrown into such a position that there is no danger of the latching notch 92 catching and holding the pin 94, so that there will be no impedance in the normal operation of the pawl 81.

It now it be desired to lower the load under control, the adjusting handle is swung to rotate the head 18 counterclockwise until the offset lug 82 engages the spring portion 16. This places tension in the reverse direction to bias the pawl 1| out of engagement with the ratchet teeth of the ratchet 98. 1f the handle is raised to the uppermost limit of its stroke, pin I94 will strike the face I92 'of the arm 98 and in doing so will rock thering :91 in a clockwise direction, and in a direction so that the slot '99 operating on pin 15 on the holding pawl 1I will move this pawl into engagement with a tooth of the ratchet 68, and in a position to hold the ratchet from rotation under load on .the chain. At the same time the pin I94 upon striking the face I82 of the'arm 98, will rock the holding pawl 81 on'its pivot until the latching'notch .92 on the latch 9| will engage the pin 94 on the pa-wl 81 holding the pawl in its disengaged position. Therefore, as the handle is'rocked downwardly the load pawl 81 will be freeto move over the ratchet 58 until the handle reaches its lowermost position. When the handle reaches its lowermost position, the latch ill will strikethe projection I91 of the pin I96 throwing the latch .out of en gagement with the pin 94, thereby releasing the load pawl so that iit-can be biased into engagement with atooth of the ratchet 6B and in a position to control the lowering of theload. In this position a slight downward movement of the handle will rotatethe ratchet slightly to relieve the holding pawl of pressure so that the holding pawl may move into disengaged position permitting the-shaftv to rotate clockwise under control of load pawl 81.

It is to be remembered that with the spring biasing the holding pawl 1| normally out of engaging position as in the case of lowering, if it be desiredto have afr'ee chain operation of the load wheel, the handle after having moved to the limit of its utmost position'to release pawl 1|, as heretofore described, may be lowered but short of and not to the extent that latch 9| will engage theprojection I91. Thus the latch 9| will retain paw1 81 in its disengaged positionj Under these circumstances, the'holding'pawl and the operating pawl are both inoperative, and the l'oacl'wheel is free to rotate without obstruction If it be desired to operate the device with the handle operating from the'right side, as. distinguished from the left side as shown inthe drawinsis, the handle at is raisedsufiicientl lugh for the pin. I04 toengage the face I02 of the arm 98. This will throw the pawl 81 down to the point where the pin or thereon W111 engageinthe men notch a2 on the latch'fil, holding the pawl in its outward or .diseng ged position relative to the ratchet 98. At, the same time the'pin I96 is moved to the left, Fig. 3,'and given a half turn so. that. it will be held in its left hand position, this retracts the projection I81 fro'mfthe. path of the pawl 81. and its associated latch 9|.. With the pawl 81 held in its retracted position and the pin projection I01 out of the path, the handle can be then swung around until the handle is on the right hand side of the hoist, the pawl 81 and its latch 9| being retracted sufficiently far to clear the arm I on the ring 91. If the handle, under these circumstances, is raised considerably until the latch 9| engages the stop pin H2, this will release the latch, in turn releasing the pawl 81, so that the pawl can now be biased into engagement with the ratchet. Under these circumstances, the load may be hoisted by oscillating the handle except, in this instance, the hoist pressure will be applied upwardly on the handle to rotate the ratchet 68 and shaft 65 in a counterclockwise direction.

If it be desired to lower the load, the adjusting handle 80 will be swung in a direction opposite to that shown in Fig. 2 to place the spring 16 under a biased tension to bias the pawl 1| out of engaging position with respect to the ratchet teeth of the ratchet 68. However, with the handle being held in its now elevated position the pawl 81 will be in position to engage the ratchet teeth, and by lowering the handle the rotation of the ratchet and the load wheel, under load, will be effected in a clockwise direction. When, however, the handle is lowered to its lowermost position, the pin I04 on the pawl 81 will strike the face of the arm I05, rotating this arm sulficiently to cause the holding pawl 1! to move into engagement with one of the teeth of the ratchet 68. At the same time the pawl 81 through the medium of this pin I04 will be depressed sufii- -ciently far for the latch pin 9 on the pawl to engage in the notch 92 on the latch member 9i, holding the pawl out of engaging position relatively to the ratchet teeth 68; and the handle may then be swung up freely, the load being held by the holding pawl until the handle is sulficiently raised for the latch 9! to engage the pin H2. This will release the pawl 81 permitting it to move into engagement with one of the teeth of the ratchet 68, again permitting the load to lower.

If it be desired to effect free chaining, the pawl 1| is biased into its disengaged position and the handle 84 is operated only to an intermediate point, that is, not raising the handle until the latch 9| reaches the pin H2. The pawl 87 will then be held out of engagement so that neither the holding nor load pawl are operative, and the chain and ratchet with the chain wheel may be freely moved.

While the invention has been illustrated and described in great detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character.

The several modifications described herein as well as others which will readily suggest themselves to persons skilled in this art, all are considered to be within the broad scope of the invention. reference being had to the appended claims.

The invention claimed is:

l. A hoist structure including a housing mounting a shaft, a load supporting wheel on said shaft, a co-axial offset ratchet wheel thereon, a holding pawl pivoted on said housing for ratcheting engagement with said ratchet wheel, a spring normally biasing said pawl into ratchet engaging position, an operating handle pivoted on said housing in co-axial relation to said wheel, a load pawl pivoted on said handle, a spring onsaid handle engaging said load pawl for biasing it into ratcheting engagement with said ratchet wheel, a latch pivoted on said handle in biased engagement with said last-mentioned spring movable into and out of latching engagement with said load pawl, a control member movable to reverse the tension on said first-mentioned spring to bias said holding pawl out of ratchet wheel engagement, and a control ring mounted for rotation on said shaft adjacent said ratchet wheel having a radially projecting camming member operably connected with said holding pawl engageable by said load pawl at the end of its load lowering stroke to effect holding pawl engagement with said ratchet wheel and engagement by said latch to be latched from ratchet wheel engagement during its return stroke.

2. A hoist structure including a housing mounting a shaft, a load supporting wheel on said shaft, a co-axial offset ratchet wheel thereon, a holding pawl pivoted on said housing for ratcheting engagement with said ratchet wheel, a spring normally biasing said pawl into ratchet engaging position, an operating handle pivoted on said housing in co-axial relation to said wheel, a load pawl pivoted on said handle, a spring on said handle engaging said load pawl for biasing it into ratcheting engagement with said ratchet wheel,

a latch pivoted on said handle in biased en-' gagement with said last-mentioned spring movable into and out of latching engagement with said load pawl, a control member movable to reverse the tension on said first-mentioned spring to bias said holding pawl out of ratchet wheel engagement, a control ring mounted for rotation on said shaft adjacent said ratchet wheel having a radiallyprojecting camming member operably connected with said holding pawl engageable by said load pawl at the end of load lowering stroke to effect holding pawl engagement with said ratchet wheel and engagement by said latch to be latched from ratchet wheel engagement during its return stroke, and a retractible pin movable in said housing into and out of the path of movement of said latch to be inoperative relative thereto when in one position and engageable thereby when in another position to unlatch said load pawl when moved to its other extreme position for ratchet wheel engagement.

3. A hoist structure including a housing mounting a shaft, a load supporting wheel on said shaft, a co-axial offset ratchet wheel thereon, a holding pawl pivoted on said housing for ratcheting engagement with said ratchet wheel, a spring normally biasing said pawl into ratchet engaging position, an operating handle pivoted on said housing in co-axial relation to said wheel, a load pawl pivoted on said handle, a spring on on said handle in biased engagement with said last-mentioned spring movable into and out of latching engagement with said load pawl, a control member movable to reverse the tension on said first-mentioned spring to bias said holding pawl out of ratchet wheel engagement, a control ring mounted for rotation camming member on the oppositeside-of said ring from said'first-mentioned member operative to actuate said holding pawl upon'reversal of said load pawl. t

4. A hoist structure including a housing mounting a shaft, a load wheel and ratchet on said shaft, a holding pawl positioned for ratcheting engagement with said ratchet, an operating handle pivoted on said housing in co-axial relation to said ratchet, a load pawl pivoted on said handle biased in ratcheting engagement with said ratchet, a load pawl latch operative to latch said lead pawl .out of ratchet engagement, a control member operative to bias said holding pawl out of ratchet engagement, a control ring engageable by said load pawl at the end of one stroke to move said'holding pawl into ratchet engagement, and a projection on said housing engageable by said latch'to release said load pawl forratchet engagement at the end of its stroke in the opposite direction.

'5. A hoist structure as defined by claim 4 wherein said control ring and holding pawl are provided with a free play pin and slot connection to freely permit biasing of said pawl into ratchet engagement and positively move said pawl to ratchet engagement when biasedtherefrom.

6. A .hoist structureas defined by claim 4 whereinsaid control ring-is providedwith one projection operatively connected with said holding pawl, .and .an oppositely disposed projection, either ofsa-id projections being engageable by said load pawl for actuation to move said holding, pawl :to ratchet engagement and swing said loadpawl outof ratchet engagement.

'L-A ,hoiststructure as defined by claim 6 wherein the projection on saidhousing consists of a transversely movable pin operable when retracted to permit said load pawl and its operating handle :to be swung to the opposite side of said pawl in reversed position to engage said second-mentioned control ring projection.

JAMES R. COFFING.

, References Cited in the file of this patent UNITED STATES PATENTS

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