US2884226A

US2884226A - Cable and ratchet wheel lifting jack

Info

Publication number: US2884226A
Application number: US532354A
Authority: US
Inventors: Joseph F Palka
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-09-02
Filing date: 1955-09-02
Publication date: 1959-04-28
Anticipated expiration: 1976-04-28

Description

April 28, 1959 J. F. PALKA CABLE AND RATCHET WHEEL LIFTING JACK 2 Sheets-Sheet 1 Filed Sept. 2-. 1955 I Jbayyhj "53 v.

April 28, 1959 Filed Sept. 2.

2 Sheets-Sheet 2 United States Patent CABLE AND RATCHET WHEEL LIFTING JACK Joseph F. Palka, Chicago, 111.

Application September 2, 1955, Serial No. 532,354 4 Claims. (Cl. 254-145) The present invention relates to ratchet and pawl operable lifting jack, the objects whereof being substantially identical with those specified in my co-pending applications, Serial Nos. 301,900 and 308,382, now Patents 2,719,696 and 2,719,697, respectively.

Another object of the present invention is the provision of a lifting jack including a grooved ratchet wheel, within the groove of which a cable is wound, the free end of which carries a hook to be engaged with an automobile bumper or the like for lifting or lowering the load engaged by the hook when said ratchet is caused to rotate into one or opposite directions, with a ratchet carrying handle, a pawl, the handle ratchet acting upon the teeth of the ratchet wheel during the downward shifting of the handle for causing shifting of the ratchet wheel in one direction for winding the cable therearound, with the pawl riding upon the inclined sides of the ratchet teeth and engaging the same for preventing the reverse rotation of the ratchet wheel as the handle is shifted into the opposite, upward direction.

Another object of the present invention is the provision of suitable means whereby the ratchet and pawl may alternately engage or disengage the teeth of the ratchet wheel to advance the rotation of the ratchet wheel to the opposite direction by virtue of the pull exerted thereupon by the weight of the load upon the cable, in order to lower the object engaged by the cable hook, and to cause the intermittent operation of the said ratchet and pawl during the reciprocating movement of the handle.

With the above general objects in view and others that will appear as the invention is better understood, the same consists in the novel construction, combination and arrangement of parts hereinafter more fully described, illustrated in the accompanying drawings and pointed out in the appended claims.

In the drawings forming a part of this application, and in which like designating characters refer to correspondihg parts throughout the several views;

Fig. 1 is a side elevational view of the head portion of the present jack, within which the mechanism for winding or unwinding a load-supporting cable is supported, illustrating the mechanism for winding the cable within the ratchet wheel for raising the load engaged by the cable;

Fig. 2 is an edge elevational view of the jack mechanism taken from the edge of the reciprocating handle;

Fig. 3* is a side elevational view of the jack mechanism with the handle thereof raised for bringing the handle ratchet in engagement with the upper adjacent teeth, illustrating the position of the mechanism preparatory to the shifting of the ratchet wheel in a clockwise direction when the handle is moved downwardly;

Fig. 4 is a side elevational view of the jack illustrating the position of the mechanism at one stage of the operation of the ratchet wheel preparatory to the shifting of the latter to the counterclockwise direction when under the actuation of the load upon the cable immediately ice prior to the shifting of the handle into an upward direction; and

Fig. 5 is a side elevational view of the jack illustrating the position of the mechanism during one stage of the operation thereof for shifting the ratchet wheel to a counter-clockwise direction when under the actuation by the load weight upon the cable for lowering the load with the pawl in engagement with the ratchet wheel teeth for arresting the rotation of the ratchet wheel into the counter-clockwise direction as the handle ratchet has been released from the ratchet teeth preparatory to the springing of the handle ratchet to the next lower teeth prior to the downward shifting of said handle.

Referring in detail to the present drawings there is shown therein a pair of plates 10 and 11 within which a pair of supporting

legs

12 and 13 are positioned by their upper ends and rigidly held therewithin by means of a plurality of screws or bolts 14. Said

legs

12 and 13 constitute a supporting means upon the ground for the jack lifting and lowering mechanism supportable within and upon said plates 10 and 11. One or more spacers and bolts 16 may be provided for maintaining said plates 10 and 11 in their rigid spaced relation.

Passed through said plates 10 and 11 is shaft 17, the ends of which may be riveted against the outer faces of said plates 10 and 11 for maintaining said shaft 17 in a rigid position relative to said plates. Mounted upon said shaft 17 and located within said plates 10 and 11 is a pair of ratchet wheels 18. Interposed between said ratchet wheels 18 and rigidly connected with the inner faces thereof is drum 19, which maintains the two ratchet wheels 18 in a spaced relation, thereby defining a groove within which cable 20 may be wound and around said drum 19, as is indicated by dotted lines in Fig. 1. The inner end of said cable 20 is rigidly affixed to said drum 19, while the outer end of said cable 20 has rigidly attached thereto hook 21 for the purpose of engaging a load such as a bumper of an automobile or the like.

The two ratchet wheels 18 are provided upon their peripheries with alined ratchet teeth 22. Since the alined teeth in the two wheels 18 are adapted for engagement by the handle ratchet or a pawl, later described, the two ratchet wheels 18 in the hereinafter following description will be referred to as a single ratchet wheel 18.

The invention further includes handle 23, from the inner end of which a pair of spaced arms 24 projects. Coacting with each arm 24, and in a spaced relation with the inner face of each, is plate 25, which by one of its ends is welded or otherwise affixed to arm 24 as at 26, as is seen in Fig. 2.

Adjacent one edge of each plate 10 and 11 a bulge 27 projects. Each bulge 27 is received within the space d fined by one of said arms 24 and its connecting plate 25. Pivot pin 28 is passed through said bulge 27 and one of said arms 24 and its coacting plate 25 for providing. a pivot upon which said arms 24 and handle 23 reciprocate upon a vertical plane to their downward position shown in Figs. 1 and 4 or to their raised position illustrated in Figs. 3 and 5.

interposed between each of said arms 24 and its coacting plate 25 is arm 29. One of said arms 29 is set for a pivotal movement upon shaft 30 which is passed through one of said arms 24, arm 29 and its coacting plate 25, while the other of said arms 24, its coacting plate 25 and arm 29 are pivoted upon pin 31 which is alined with said shaft 30. Said shaft 30 and pin 311emain in a radial relation with pivot pins 28, by virtue of which arrangement said shaft 3i} and pin 31 are disposed downwardly with relation to pins 28 when handle 23 remains in a downwardly shifted position shown in Figs. 1 and 4, and remain in a radially raised position when essence said handle 23 is elevated as seen in Figs. 3 and 5. Pivots 30 and 31 engage said arms 29 at the lower end thereof. Interposed between the upper ends of said arms 29 adjacent the upper free ends thereof, and rigidly connected therewith as by welding or other suitable means, is ratchet pawl 32, the lower tapered end of which is adapted to engage ratchet teeth 22 upon wheel 13.

From the upper end of one of said arms 29 pin 33 laterally projects for the purpose of anchoring thereon one end of coil spring 34. The opposite end of said spring 34 is attached to pin 35 which laterally projects from plate 11. Said spring 34 remains under a contracted tension for normally urging ratchet 32 in contact with teeth 22 of the ratchet wheel 18. Rigidly afiixed to pin 36 below said ratchet wheel 18, is holding pawl 37, which is interposed between plates and 11. One end of said pawl 37 is connected with coil spring 38, the opposite end of which connects with .screw 39. tension for the purpose of urging the operative end of said pawl 37 in contact with teeth 22 of ratchet wheel 18. From the hereinabove description it will be apparent that when handle 23 is raised in an upward direction,

Said coil spring 38 is under a contracted as seen in Fig. 3, ratchet 32 contacts the radial surfaces of one pair of alined teeth 22 upon two wheels 18. As said handle 23 is shifted downwardly, wheel 18 will be caused to revolve about its shaft 17, in a clockwise direction as viewed in Fig. 1 for winding upon drum 19 cable 20 for the purpose of elevating a load engaged by book 21. During the rotary shifting movement of :wheel 18 induced by ratchet .32 when in an engagement with tooth 22, pawl 37 will ride upon the inclined side of the tooth until said pawl 37 clears the tooth and falls within the notch defined by the radial side of the tooth, when handle 23 has been brought to its lowermost position shown in Fig. 1.

The mechanism for unwinding cable 20 upon drum 19 for lowering the load supported by hook 21 includes a U-shaped leaf spring 40, which at one of its ends is provided with loop 41, the latter encompassing and rigidly engaging pin 42 laterally extending from plate 10, said pin 42 being set within said plate 10 for a rotary movement. Bar 43 rigidly afiixed to said pin 42 is adapted for angular shifting movement for the purpose of bringing said spring to its operative position illustrated in Figs. 4 and 5, or to its inoperative position, shown in Figs. 1 and 3.

When said spring 40 remains in its inoperative position bar 43 is engaged by a clamp clip 44. A similar clamp clip 45 is provided at some distance from the first clamp clip 44 in a downward direction to engage said bar 43 when spring 40 is in an operative position. Extending laterally from arm 29 which is oppositely disposed with relation to plate 10 is stop 46, the latter being disposed on the plane of said leaf spring 40. Said spring 40 coming in contact with said stop 46 is for the purpose of kicking off arms 29 and ratchet 32 from engagement with teeth 22, and against the tension of coil spring 34, during one stage of the operation of the mechanism for causing the unwinding of cable 20 upon drum 19 when ratchet wheel 18 is caused to move into the counter-clockwise direction, as illustrated in Fig. 5, and which action will be hereinafter described.

Supportable upon shaft 30 in a pivotal relation therewith is the shorter leg of an L-shaped member 47, which remains in a spaced relation with the adjacent arm 24. The longer free end of said L-shaped member 47 is disposed laterally of plate 10, and its free termination edge of the longer end of said L-shaped member 47 is a pair of notches 52. Supportable within said slide mem ber 51, upon pivot pin 53 is catch 54, which by its free end is adapted to selectively fall into one or the other of said notches 52. One of said notches 52 is proximate to the shorter end of said L-shaped member 47, while the other of said notches 52 is proximate to said wing 49.

Coil spring connects with the opposite end of said catch 54 for the purpose of pulling the said opposite end of said catch 54, urging the free end of said catch 54 towards the adjacent edge of the longer portion of said L-shaped member 47. The opposite end of said coil spring 55 is anchored to the bottom of said slide member 51. When the said opposite end of said catch 54, is manually depressed in an upward direction, against the tension of said coil spring 55, the free end of said catch 54 will be disengaged from one or the other of said notches 52 permitting said slide member 51 to longitudinally slide upon said longerend of the said L-shaped member 47 for the purpose of selectively springing the free end of said catch 54 into one or the other of said notches 52.

Coil spring 56 is positioned upon the said longer end of the said L-shaped member 47, and remains interposed between said wing 49 and said slide member 51. When catch 54 has been shifted with its slide member 51 toward the shorter end of said L-shaped member 47 the free end of said catch 54 will fall into notch 52 which is proximate to the said shorter end of said L:

shaped member 47, thereby releasing the tension of said spring 56 upon wing 49 and rendering said coil spring 56 loose and inoperative, the positions illustrated in Figs. 1 and 3. When said slide member 51 has been shifted to the opposite direction, that is toward said wing 49, with the free end of catch 54 falling into notch 52 which is proximate to said wing 49, said coil spring 56 will become depressed, for the purpose of exerting tension upon said wing 49. This in turn will cause the said L-shaped lever 50 to angularly shift, thereby causing rotary shifting of pin 36 for angularly shifting pawl 37 out of engagement with ratchet teeth 22, and against the action of coil spring 38. This condition prevails however when handle 23 has been shifted to its downward position, shown in Fig. 4, duringone stage of the load lowering operation for unwinding cable 20 from drum 19. During this stage of the operation the jack ratchet 32 remains in an engagement with the ratchet tooth 22. I

During the winding operation of cable 20 upon drum 19 leaf spring 40 remains in its inoperative position illustrated in Figs. 1 and 3 without affecting in any manner the operation of coil spring 34, as a consequence whereof ratchet 32 rides the inclined sides of teeth 22 during the upward shifting of handle 23, until said .ratchet 32 falls into a teeth notch and contacts the radial side of the ratchet tooth 22, as is seen in Fig. 3. During this operation catch 54 remains in notch 52 which is proximate to the shorter portion of the L-shaped member 47, thereby maintaining coil spring 56 in its loose inoperative position, without effecting wing 49 or angular shifting movement of the L-shaped lever 50, permitting pawl 37 to spring into the notch defined by repair of adjacent teeth 22 when said handle 23 has been brought to its downwardly shifted position illusis positioned within slot 48 made in wing 49. Said wing tarted in Fig. 1. Thus, during the winding operation of cable 20 around drum 19 for lifting the load weight upon hook 21

coil springs

34 and 38 remain fully operative, without counter-acting in any manner their operation by

springs

40 and 56, respectively.

It is only immediately preceding the unwinding of cable 20 from drum 19 for lowering the load weight upon hook 21, in order to bring about the rotation of the ratchet wheel 18 into a counterclockwise direction as viewed in Figs. 4 and 5, that spring 40 is brought to its operative position and that slide member 51 is shifted towards wing 49 in order to bring, the operative end of catch 54 in engagement with the longer portion of the said L-shaped member 47 at its notch 52 which is proximate to said wing 49, in order to compress coil spring 56, as is seen in Fig. 4.

When said springs 40 and 56 have been brought to their operative positions shown in Figs. 4 and 5, preparatory to the unwinding of cable 20 upon drum 19, it is noted that the free end of the longer portion of the L-shaped member 47 shifts within slot 48 in either direction, depending upon the downward or upward direction of the shifting movement of said handle 23.

In the downward shifted position of handle 23 as is seen in Fig. 4, the longer portion of the L-shaped member 47' is caused to shift to a greater extent in'slot 48', than when said handle has been shifted to the upward direction, illustrated in Fig. 5. Thus, there will be a greater degree of compression ofcoil spring 56 when handle 23 has been shifted downwardly to the full extent, than when said handle 23 has been shifted upwardly to its full extent, as seen in Fig.- 5. Therefore, when handle 23 is down spring 56 becomes fully operative in order to shift L-shaped lever 50, and thereby to disengage pawl 37 against the action of coil spring 38 thereon. Therefore, when handle 23 is down, ratchet 32 is in engagement with ratchet tooth 22 upon wheel 18 for preventing the counterclockwise shifting movement of wheel 18. Manual bearing against handle 23 when it remains in its downward shifted position will cause ratchet 32 to be engaged with tooth 22, withpawl 37 simultaneously disengaged from teeth 22 due to the action of coil spring 56' and the shifted position of the longer portion of the L shaped member 47, as was hereinabove described, and as is illustrated in Fig. 4. It is observed that during the utmost downward shifted portion of handle 23 the degree of tension of spring 56 upon wing 49 is the greatest due to'the fact that the longer portion of the L-shaped member 47 has been shifted to the greatest extent in the direction of said wing 49, thereby affecting the greatest compression of said spring 56 between said wing 49 and slide member 51.

At the inception of the upward shifting movement of handle 23 ratchet 32 continues to be in engagement with tooth 22, and pawl 37 continues to be out of engagement with tooth 22, as is seen in Fig. 4. Due to the action of the load weight upon hook 21, the pulling force of cable 20 upon drum 19 causes ratchet wheel 18 to shift to the counter-clockwise direction, until the apex of tooth 22 oppositely disposed to the operative end of pawl 37 as seen in Fig. 4 clears said pawl 37.

During the further upward shifting of handle 23 ratchet 32 remains in engagement with tooth 22, with wheel 18 continuing to be shifted to the counter-clockwise direction, until the next succeeding tooth 22 (at the left side in the upright direction as viewed in Fig. 4) comes in engagement with pawl 37. The further angular shifting movement of handle 23 in an upward direction brings stop 46 in contact with leaf spring 40, and the action of said latter spring kicks off ratchet 32, against the action of coil spring 34, and :brings said ratchet 32 out of engagement with tooth 22 with which said ratchet 32 was theretofore in engagement, position illustrated in Fig. 5. During this last described operation pawl 37 continues to remain in engagement with the next succeeding tooth 22 in a clockwise direction, as is seen in Fig. 5. Downward shifting of handle 23 from its position shown in Fig. 5 will cause ratchet 32 to skip the apex of tooth 22 0ppositely disposed to the operative end of said ratchet 32 in order that said ratchet 32 may fall within the notch defined by the next succeeding tooth 22 in a clockwise direction as seen in Fig. 5. Further downward movement of handle 23 and the consequent pressure of ratchet 32 upon said latter succeeding tooth 22 will cause wheel 18 to shift to a very short distance in a clockwise direction, sufiicient to clear pawl 37 from its engagement with tooth 22 with which the same was theretofore in engagement, as seen in Fig. 5 in order to bring said pawl 37' to its inoperative position shown in Fig. 4. Further downward shifting of handle 23 will bring the latter to the position shown in Fig. 4 to repeat the unwinding operation of cable 20 from its drum 19.

From the hereinabovedescribed operation of the cable lowering mechanism it will be noted that during each shifting movement of handle 23 from its lowermost positionshown in Fig. 4 to its upward position shown in Fig. 5, and then again. from its uppermost to its lowermost positions, the rotation of ratchet wheel 18 to the counterclockwise direction has been advanced to the extent of the arcuate portion of said wheel 18 equivalent to the length of the inclined length of each tooth 22.

From the hereinabove description it will be apparent that the L-shaped member 47, and more specifically its longer horizontal portion, in conjunction with its coil spring 56, acts as a tensioned arm for actuating said wing 49 and through it the L-shaped lever 50 for inducing the disengagement of pawl 37 from the teeth of the ratchet wheel 18, as is seen in Fig. 4.

While there are described herein preferred embodiments of the present invention, it is nevertheless to be understood that minor changes may be made therein without departing from the spirit and scope of the invention as claimed.

What I claim as new is:

1. A jack for alternately lifting. or lowering a load comprising a supporting member, a ratchet wheel journalled upon said supporting. member for rotary movement and having teeth thereon, said ratchet wheel having a drum portion, a cable wound about said drum portion and having a load-engaging portion leading downwardly from said drum on one side of the axis of rotation thereof, a handle pivoted at one of its ends upon said supporting member for angular movement about an axis displaced from the axis of said ratchet wheel on the side thereof opposite to that from which said cable leads downwardly, a holding pawl normally in engagement with the teeth of said ratchet wheel for preventing the latter from rotating in the direction of the pull exerted upon said ratchet wheel by the load weighted cable, a ratchet pawl pivotally mounted on said handle near the periphery of said ratchet wheel, tensioning means carried by said supporting member and connecting with said ratchet pawl for urging the latter in contact with the teeth upon said ratchet wheel, a tensioned arm carried by said handle in a pivotal relation therewith, said tensioned arm exerting pressure upon said holding pawl for disengaging the latter from the teeth upon said ratchet wheel when said handle has been shifted to one position in its angular shifting movement and while said ratchet pawl remains in engagement with the teeth upon said ratchet wheel, when said handle is shifted to the opposite direction said tensioned arm being shifted therewith for permitting said holding pawl to fall in engagement with an adjacent tooth upon said ratchet wheel due to the shifting movement of said ratchet wheel by virtue of and in the direction of the pull exerted upon said ratchet wheel by the load weighted cable for lowering the load, and tripping means for deflecting said ratchet pawl away from the teeth upon said ratchet wheel against the action of said tensioning means for disengaging said ratchet pawl from the tooth upon said ratchet wheel with which said ratchet pawl was theretofore in engagement when said handle has been shifted to the opposite direction, upon operation of said tripping means said ratchet pawl being adapted to engage the adjacent tooth upon said ratchet wheel in the direction counter to the pull exerted upon said ratchet wheel, said tensioned arm becoming operable instantaneously for disengaging said holding pawl from the teeth of said ratchet wheel when said ratchet pawl comes in engagement with the last named tooth upon said ratchet wheel.

2. In a lifting jack, a support, a ratchet wheel rotatably mounted on said support, a handle pivotally mounted on said support, a ratchet pawl pivotally mounted on said handle, a holding pawl pivotally mounted on said support, resilient means for continuously urging said pawls toward the periphery of said ratchet wheel, selectively operable means for moving said ratchet pawl out of engagement with the teeth of said ratchet wheel in a peripheral zone corresponding to the last part of the driving stroke and the first part of the idle stroke of said ratchet pawl, and selectively operable means for transmitting force from said handle to said holding pawl so that motion of said handle in a zone corresponding to the last part of the idle stroke of said ratchet pawl tends to move said holding pawl out of engagement with the teeth on said ratchet wheel, said last-mentioned means including a spring through which said force may be transmitted and an adjustable stop member adjacent said spring adapted to be secured in either a'first position in which it will load said spring during such motion of said handle or a second position in which said spring will not be loaded during such motion.

3. In a lifting jack, a support, a ratchet wheel rotatably mounted on said support, a handle pivotally mounted on said support, a ratchet pawl pivotally mounted on said handle, a holding pawl pivotally mounted on said support, resilient means for continuously urging said pawls toward the periphery of said ratchet wheel, selectively operable means for moving said ratchet pawl out of engagement with the teeth of said ratchet wheel in a peripheral zone corresponding to the last part of the driving stroke and the first part of the idle stroke of said ratchet pawl, selectively operable means for transmitting force from said handle to said holding pawl so that motion of said handle in a zone corresponding to the last part of the idle stroke of said ratchet pawl tends to move said holding pawl out of engagement with the teeth on said ratchet wheel, said last-mentioned means including a first member mounted for movement with said holding pawl and having an opening therethrough, a second member pivotally mounted on said handle and having an end portion extending loosely through said opening, a coil spring loosely surrounding said second member and abutting against said first member, and an adjustable stop mounted on said second member and adapted to be secured in either a first position in which it will compress said spring during such motion of said handle or a second position in which it will not compress said spring during such motion.

4. In a lifting jack, a support, a ratchet wheel rotatably mounted on said support, a handle pivotally mounted on said support, a ratchet pawl pivotally mounted on said handle, a holding pawl pivotally mounted on said support, resilient means for continuously urging said pawls toward the periphery of said ratchet wheel, an adjustable member including a resilient cam surface and adapted to be moved between a first position in which said resilient cam surface contacts said ratchet pawl in a peripheral zone correspond; ing to the first part of an idle stroke of said ratchet pawl to urge said ratchet pawl out of engagement with the teeth on said ratchet wheel and a second position in which said member is spaced from the path of said ratchet pawl, and selectively operable means for moving said holding pawl out of engagement with the teeth on said ratchet wheel when said ratchet pawl is moved into a zone corre sponding tothe first part of a driving stroke thereof.

References Cited in the file of this patent UNITED STATES PATENTS