US2970490A

US2970490A - Hoist structure

Info

Publication number: US2970490A
Application number: US789969A
Authority: US
Inventors: Robert L Winland
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-01-29
Filing date: 1959-01-29
Publication date: 1961-02-07
Anticipated expiration: 1978-02-07

Description

Feb. 7, 1961 RQL. wlNLAND HOIST STRUCTURE Filed Jan. 29. 1959 5 Sheets-Sheet 1 IN1/EN ToRs. Raaf/w* W/fw. HND.

R. L. WINLAND Feb. 7, 1961 HOIST STRUCTURE :5' sheets-sheet 2 Filed Jan. 29. 1959 Feb 7, 1961 R. L. WINLAND 2,970,490

HoIsT STRUCTURE Filed Jan. 29. 1959 3 Sheets-Sheet 3 IN1/EN T0125 Raaf/97' L W//w AND.

United States This invention relates generally to hoist structures and in particular to a hoist structure having a minimum number of parts and a simplified construction.

In Cotlng Patents 2,647,724 and` 2,647,725 there is disclosed and claimed hoist structures of the ratchet type capable of load lowering and load elevation as well as free running action. The present invention is directed to an improved ratchet type hoist which can be manufactured at relatively low cost and which is lighter in weight than prior art hoist structures.

The primary object of the present invention is to provide a simplified hoist structure having a minimum of component parts, the structure requiring no close tolerances in the forming of its components.

-A further object of the present invention. is to provide a hoist structure utilizing a ratchet, a load pawl and a handle pawl, these elements cooperating so that, during a load lowering operation, movement of the handle pawl during an upward stroke of the handle urges the load pawl into ratchet engagement for holding the load during a downward stroke of the handle.

A further object of the present invention is to provide a hoist structure of the type described above wherein at the limit of the upward stroke of the handle during a load lowering operation the handle operated pawl is engaged by the load pawl to detent the handle pawl outwardly of the ratchet, the handle pawl remaining in this detent position until the final portion of the downward stroke of the handle whereupon it is forced into ratchet engagement to release the load pawl in preparation for the succeeding upward stroke of the handle.

A further object of the presentinvention is to provide a hoist `structure which, `in a modified form, accomplishes the coaction of parts above described with a minimum number of biasing springs.

A further object of the present invention is to provide a hoist structure having the components referred to above in which the load pawl is operated by a torsion spring,

one of the free ends of the spring being displaceable for selectively urging the load pawl into or out of engagement with the ratchet depending upon whether a load lowering or load raising operation is desired.

A further object of the present invention is to pro` vide a hoist structure of the type referred to above in which a simplified connection is provided between the shiftable free end of the load pawl torsion spring and a manually movable member, the connection permitting the free end of the torsion spring to be displaced as the manually movable member is rotated or angularly moved.

A AA further object of the present invention is to provide a hoist structure of the type referred to above in which the load pawl and handle pawl have identical contiguration and dimensionlthereby simplifying the'stocking of parts and facilitating manufacture and assembly. 1

"A further vobject vofthe present invention is to pro-'Q vide ahoist structure of thetype referred to which sso'y 70 constructed and arranged that a maximum number of` datent component parts, including pawls, springs and are interchangeable on models of the structure designed for various loadings over a relatively wide range of load capacities.

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

Fig. 1 is an end sectional view of a hoist structure embodying the present invention.

Fig. 2 is a side sectional view taken line 2-.-`2 of Fig. 1.

Fig. 3 is a fragmentary side view of the structure taken from the opposite side from that viewed in Fig. 2.

Fig. 4 is a view similar to Fig. 2 but showing the components at one portion of a load lowering cycle.

Fig. 5 is a view similar to Fig. 4, but showing the structure in a further portion of a load lowering cycle.

Fig. 6 is a View similar to Fig. 4, but showing theV components positioned in a further portion of a load lowering cycle. l

Fig. 7 is a fragmentary sectional view taken generally along the line 7-7 of Fig. 6.

Fig. 8 is a view similar to Fig. 1, but illustrating a. modified form of the ratchet and pawl mechanism.

Fig. 9` is a sectional view taken generally along the' line 9 9 of Fig. 8. n

Referring initially to Figs. 1, 2 and 3, the hoist structure includes a housing 10 which is apertured to support a shaft 11. Sleeve bearing 12 journals one end of the shaft in the housing and an enlarged portion 11a ofthe. shaft is further journaled in the housing by sleeve bear;

generally -along the ing 13. A central cavity within the housing accom.

modates a chain sheave or load supporting wheel 14, the wheel having a load bearing chain 16 passing thereover. Extending from the upper portion of the housing andi shown only fragmentarily in Fig. 1, is a conventional swiveled supporting hook 17. `A generally cup-shaped handle carriage 13 overlies` one side of the housing and is centrally apertured to'accommodate a sleeve bearing 19 which journals the ex` tending end of the shaft 11'1. Snap-on retainer rings 21 hold the shaft, handle carriage and housing in assembled relation. As may be seen in Fig. 2, the handle carriage is formed `so as to accommodate a handle element 22 which extends from one side thereof.

A ratchet wheel 23 is locked upon the shaft 1'1 by, means of a key 24. Extending from the side of the hous-` ing is a load pawl pin 26 which pivotally supports a load pawl 27 having a ratchet engaging tooth 27a and a nose:

portion 27b.

Extending inwardly from the under face of the han-i dle carriage is a handle p-awl pin 28 upon which is pivotally mounted a handle pawl 29 having a ratchet en` gaging tooth 29a and an extending portion 29b. A means for biasing the handle pawl into ratchet engaging( position is provided by thelcoiled torsion spring 31, one.- end of which 31a engages the handle pawl and the other` end engaging the adjacent side wall of the handle car' riage. The handle pawl is apertured, as may best be seen in Fig. 7, to accommodate a compression spring 32 which? urges a detent member in the form of a steel ball 33 into 1 a detent recess 34 formed in the inner end face offthe",` handle carriage 18. The `detent recess 34 is so positioned? that the ball 33 is seated inthe recess only when 'the han-n.v dle pawl 29 is positioned clear of the ratchet wheel 23, L this position of the handled pawl being shown in Fig. 45; A pin 36 extending from the housing supports;avresilifV l entmember 37 which is `positioned so as to engage they 39. The member 39 isvsupported on a horizontal shaft 41 (Fig. 3) accommodated in the housing, the extending end of the shaft 41 being provided with a control lever 42'. It will be understood that by' moving the control' lever from. itsp'osition' of." Fig. 3 to` al position displaced 180 therefrom, Ithe selector' member- 39 will be positioned on the opposite side of the boss 38, these two alterna-tepos'itions of' the selector member being.l shown in Figs. 2 and 3. The housing maybe inscribedwitha suitable legend indicating the lowerin'g'fand load elevating positions of the member 42.

As may be seen in Fig. 2, thehandle carriagey is`A pro vided with asho'ulder or abutment 431 wliichiis adapted to engage the member 39 under certain conditions of operation ofV theV hoist structure.

As may be seen in Fig. 2, the memberSQ-is apertured toy receive a member 44-forming an eyelet extending from the outer face of the selector member 39, the eyelet being. freely rotatable with relation to the selector member. Thiseyelet may be conveniently provided by utilizing a small cotter pin, the head of the cotter pin providing the required eyelet. Extending slidably through the eyelet 44 is one end portion of a torsion spring 46 which is coiled about a'boss on the housing underlying the pin 26, as shown in Fig. 1. The opposite end portion of the spring 46 extends beneath the load pawl 27 and through an eyelet 47 depending from' the load pawl. The eyelet may be provided by a cott'er pin head as described with reference to eyelet 44. This end portion of the spring 46- extendsV beyond the" load pawl and is formed to provide-aV curved portion 46a'. Thel portion 46a of the spring is adapted'to engagethe' extending end of the pin 28'? under certain conditior'is ofoperation of the structure.V As' may be seen in Fig. 7, ythe portion of the pin` 281 engaged by the spring portion 46a may be provided with a V-groov'e indicated at' 28a.

In describing the operation, a load elevating cycle will initially be described. Under these conditions the control member 42 will be positioned solas to extend toward the up legend on the housing, thereby positioning the selector member 39 in its position shown in Fig. 2. With the member 39 so positioned, the extending end of the load pawl spring 46 will be disposed so that the spring urgesv the Itooth 27a of the load pawl 27 into engagement with the ratchet wheel. The limit of the upward stroke of. theJ handle is defined by engagement of the abutment 431 with the selector member 39.

yAs the handle is moved downwardly from its position ofvFi'g. I, the tooth 29a of the handle pawl will engage the ratchet wheel, causing itto move counterclockwise. This counterclockwise rotation ofthe ratchet wheel rotates' the sheave 14 to move the chain 16 in a load e1evating direction. At the lower portion of the load ele vating stroke, the handle pawl isv engaged by the member 37, this engagement serving to add to the force exerted by spring 31 in urging the handle pawl tooth 29a into the ratchet wheel. At the start of the upward or cooking portion of the load lifting stroke, the load will be held by the load pawl 27 and the handle' may be moved upwardly to its position of Fig. 2 and .the cycle may then be repeated.

For loadA lowering the control member 42 is moved to its position of Fig. 3, thereby placing the `selector member 39in its position of Figs. 4, 5` and 6. As will be evident from Fig. 4, under these conditions the load pawl spring is positioned so that its biasing force is reversed and the load` pawl 27 is urged clear of the ratchet wheel. The hzmdle pawl 29 is engaged inthe ratchet wheel, and as the handle 22 is moved upwardly from its position of Fig. 4 the-ratchet' wheel will follow the movement of the handle pawl wththe weight of the load rotating the ratchet wheel clockwise.

AS the` handle is moved between its positions of Figs. lMindE 5i theportion146a of the load pawl spring will engage-'die pin 28:- Theextending end of the spring 46 will thereupon be displaced inwardly so that the tooth- 27a of the load pawl will engage the ratchet wheel. It should be noted that engagement of the portion 46a of the load pawl spring with the pin 28 reverses the bias of the spring 46 so that the load pawl is urged into engagement with the ratchet wheel independently of the position of the opposite end ofthe spring 46. The weight of the load tends to hold the load pawl in engagement with the ratchet wheel, and as the handle reaches its position of Fig. 5, the extending portion 29h of the handle pawl engages the nose 27h of the load pawl. This engagement moves the handle pawl about the pin 28 so that the detent member 33 is positioned in the detent recess 34, the handle pawl thus being held in its position of Fig. 5, that is, clear of the ratchet wheel.

On the downward stroke of the handle, the load is held by the load pawl, as shown in Fig. 6. As the handle reaches its position of Fig. 4, engagement of the handle pawl with the member 37v forces the handle pawl out of detent position and into engagement with they ratchet wheel. A slight further movement of the handle downwardly beyond the position at which thev handle pawl engages the ratchet wheel, will result in releasing the load pawl from the ratchet wheel. As the handle is subsequently moved upwardly, the ratchet wheel willl be rotated clockwise by the load and the cycle is repeated.

To free-chain the mechanism, the control lever 42 is" `pawl is engaged by the portion 2'7b of the load pawl 27 to move the handle pawl clockwise, as viewed inFig'. 5.

This movement of the handle pawl places the ball 33 in the detentr depression, thereby holding the handle pawl out of engagement with the ratchet as previously described. The handle 22 is then moved to a horizontal position and by subsequently pulling. the non-load side of the chain 16 (the left-hand section of the chain as viewed in Fig. 2), the load pawl 27 will be forced clear of the ratchet by the load pawl spring 46. Both are thereby disengaged from the ratchet, allowing the chain' 16 to be pulled through the hoist in either direction.

Referring now to Figs. 8 and 9, a modied form of the hoist structure is shown wherein the handle pawl spring 31 and the resilient blade 37 are eliminated.v In Figs.

8 and 9, members identical to those in previously de scribed figures are given thev same reference numerals. As may best be seen in Fig. 9, the handle carriage 18d is provided with a relatively larger conical detent depression 51 which is adapted to accommodate the ball 33 carried by the handle pawl 29, the pawl being urged into the depression by the spring 32; Spaced somewhat radially outwardly from the depression 51 is a smaller conical detent depression 52 which is also adapted to receive' the ball 33 under certain conditions ofv operation of the hoist mechanism.

The detent depression 52 has a function identical to that of depression 34 shown in Fig. 7, that is, it serves to hold the handle pawl 29 away from the ratchet during a portion of the lowering cycle. The larger depression 51 isutilized in the raising cycle. The action of the ball 33 in centering itself at the bottom of the depression 31 serves to force the handle pawl 29 into the ratchet 23 duringthe working stroke of the raising cycle. The force of spring 32 urging the ball against the inclined sides of the depression 51 thus serve to perform the function of the handle pawl spring 29 shown in the previously described form of the invention, thereby permitting thisV structure to be eliminated.

The stud 53 extending from the housing engagesk the handle pawl as the handle 22 is moved downwardly during a loweringA cycle. Engagement serves to force the ball 33 out of the depression 52 and into the larger depression 51, whereby the handle pawl is urged into enp gagemen't' with the' ratchet to permit the load to be lowered as the handle 22 is subsequently moved upwardly. The stud 53 thus serves the same general function as the resilient means 37 referred to in the previously described form of the invention.

From the foregoing it will be evident that the hoist structure herein described utilizes only a single ratchet fwheel and identically formed pawls, thereby simplifying the stocking of parts for the structure.

While the invention has been disclosed and described in some detail in the drawings and foregoing description, they are to be considered as illustrative and not restrictive in character, as other modifications may readily suggest themselves to persons skilled in this art and within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is:

1. A hoist structure including a housing mounting a shaft, a load supporting wheel on said shaft, a coaxial olset ratchet wheel thereon, a pin carried by said housing, a load pawl pivotally supported on said pin for ratcheting engagement with said ratchet wheel, a torsion spring coiled about said pin and having its opposite end portions extending tangentially therefrom, one end portion being anchored to said load pawl and having its terminal portion extending beyond said load pawl, a selector member supported on said housing and manually movable from the exterior thereof between a. iirst and second position, connecting means between the other end .portion of said torsion spring and said selector member whereby with said selector member in said first position said spring biases said load pawl into ratcheting engagement with said ratchet wheel and out of ratchet engagement there-l with when said selector member is in said 4se,cond posi tion, an operating handle pivoted on said housing in coaxial relation to said ratchet wheel, a handle pawl pivotally supported on said handle and biased into ratcheting engagement with said wheel, a member carried by said handle adapted to displace said terminal portion of said torsion spring as said handle is moved in one direction with relation to said housing, whereby said load pawl is biased into ratcheting engagement with said ratchet wheel notwithstanding the disposition of said selector member in its said second position.

2; Ahoist structure includinga housing mounting a shaft, a `load supporting wheel on said shaft, a coaxial offset ratchet wheel thereon, a pin carried by said housing, a load pawl pivotally supported on said pin for ratcheting engagement with said ratchet wheel, a torsion spring coiled about said pin and having its opposite end portions extending tangentially therefrom, one end portion being anchored to said load pawl, a selector member supported on. said housing and manually movable between a rst and second position, connecting means between the other end portion of said torsion spring and said selector member whereby with said selector member in said iirst position said spring biases said load pawl into ratcheting engagement with said ratchet wheel and out of ratchet engagement therewith when said selector member is in said second position, an operating handle pivoted on said housing in coaxial relation to said ratchet wheel, a handle pawl pivotally supported on said handle and biased into ratcheting engagement with said wheel, a member carried by said handle adapted to displace the anchored end portion of said torsion spring as said handle is moved in one direction with relation to said housing, whereby said load pawl is biased into ratcheting engagement with said ratchet wheel notwithstanding the disposition of said selector member in its said second position.

3. A hoist structure including a housing mounting a shaft, a load supporting wheel on said shaft, a coaxial ratchet wheel thereon, a load pawl pivotally supported on said housing for ratcheting engagement with said ratchet wheel, a resilient means biasing said load pawl into engagement with said ratchet wheel, a selector member supported on said housing and .manually movable between a first and second position, connecting means between said resilient means and said selector member whereby the biasing force exerted by said resilient meansY on said load pawl is reversed as said selector member is moved between said positions, an operating handle pivoted on said housing in coaxial relation to said ratchet wheel, a handle pawl pivotally supported on said handle and biased into ratcheting engagement with said wheel, a mem-` ber carried by said handle adapted to engage said resilient.

ment with said ratchet wheel, a selector member supported on said housing and manually movable between a first and second position, connecting means between said resilient means and said selector member whereby the biasing force exerted by said resilient means on said load pawl is reversed as said selector member is moved between said positions, an operating member supported on said housing and movable with relation thereto, an abutment on `said operating member adapted to enga'gevsaid resilient means as said member is moved in one direction t with relation to said housing, whereby said load pawl is biased into ratcheting engagement with said ratchet wheel independently of the position of said selector member.

v5. A hoist structure including a housing mounting a shaft, a load supporting wheel on said shaft, a coaxial offset ratchet wheel thereon, a load pawl pivoted on said housing for ratcheting engagement with said ratchet wheel, an operating handle assembly pivoted on said housing in coaxial relation to said ratchet wheel, a handle pawl pivotally supported on said handle assembly and .biased into ratcheting position, resilient means biasing said load pawl into ratchet engaging position during a load lifting stroke of said handle assembly, a selector member movable to reverse the force exerted by said resilient means to bias said load pawl out of ratchet wheel engage- -ment during a load lowering stroke of said handle assembly, cooperating detent means carried by said handle pawl and said handle assembly defining a detent position for said handle pawl wherein said handle pawl is disengaged from said ratchet wheel, said handle pawl being adapted to engage said load pawl at one extreme portion of a load lowering stroke of said handle assembly to thereby be displaced into said detent position, and a member carried by said housing adapted to engage said handle pawl at the other extreme portion of a load lowering stroke to remove said handle pawl from said detent position and place it in engagement with said ratchet wheel.

6. A hoist structure including a housing mounting a shaft, a load supporting wheel land a ratchet wheel on said shaft, `a load pawl pivoted on said housing for ratcheting engagement with said ratchet wheel, an operating handle assembly pivoted on said housing, a handle pawl pivotally supported on said handle assembly and biased into ratcheting position, resilient means biasing said load pawl into ratchet engaging position during a load lifting stroke of said handle assembly, a .selector member movable to reverse the force exerted by said resilient means to bias said load pawl out of ratchet wheel engagement during a load lowering stroke lof said handle assembly, cooperating detent means carried by said handle pawl and said handle assembly deiining a detent position for said handle pawl wherein said handle pawl is disengaged from said ratchet wheel, said handle pawl being adapted to engage said load pawl at one extreme portion of a load lowering stroke of said handle assembly to 7 thereby -be-di's'placed into said detent position, and a niemb'er carried by 'said housing'` adapted to engage said handle pawl' at theth-er eXtreme portion of a load loweringVV sti-'oke to remove saidliandle pawl from said detent position .and vinto engagement with said ratchet wheel'.

7; A hois't structure including a housing mounting a shaft, a load supporting wheel on said shaft, a coaxial oiset ratchet wheel thereon, a `load pawl pivoted on said housing -for ratcheting engagement with said ratchet wheel,V an operating handle assembly pivoted on said housing in coaxial relation to said ratchet wheel, a handle pawl pivotally `supported on said handle assembly, means biasing said handle' pawl into ratcheting position, said last mentioned means comprising a conical recess in said handle assembly and a ball spring biased from said handle pawl' into said recess, resilient means biasing said load pawl into ratchet engaging position during a load lifting stroke of said handle assembly, a selector member movable to reverse the force exerted by said resilient means to bias said load pawl out of ratchet Wheel engaement during a load lowering stroke of said handle assembly, cooperating `detent means carried by'said handle pawl and said handle assembly dening a detent position for said handle pawl wherein said handlepawl is disengaged from said ratchet wheel, said handle pawl being adapted to engage said load pawl at one extreme portion of a load lowering stroke of said handle assembly, whereby said ball is displaced from said recess and said handle pawl is moved into said detent position, and a member carried -by said housing adapted to engage said handle pawl at the other'extreme portion of a loadlowering stroke to` remove said handlev pawl from Said detent position and to place said ball in said recess.

8. A hoist structure including a housing mounting av shaft, a load supporting wheelV and -a ratchet wheel on said shaft, a load pawl pivoted on said housing for ratcheting engagement with said ratchet wheel, an operating handle assembly pivoted on said housing, a handle pawl pivotally supported on said handle assembly, means biasing said handle pawl into ratcheting position, said last mentioned means comprising cooperating detent elements carried by said handle assembly and said handle pawl defining a first detent position for said handle pawl wherein said pawl is in ratchet engaging position, resili` ent means biasing said load pawl into ratchet engaging position during" a load lifting stroke of said handle assembly, a selector member movable to reverse the force exerted' by said resilient means to bias said load pawl out of ratchet wheel engagement during a load lowe'rl ing stroke of said handle assembly, cooperating detent means carried by said handle pawl and said handle assetti# bly defining a second Idetent position for said handle pawl wherein said handle pawl is disengaged from said ratchet wheel, said handle pawl being adapted to engage saidy load pawl at one extreme portion of a load lower`- ing stroke of said handle assembly to thereby be dis-v placed into said second detent position, and a member carried by said housing adapted to engage said handle pawl at the other extreme portion of a load lowering stroke to displace said handle pawl into said first detent position. t

9; A hoist structure including ahou'sing mounting a shaft, a load s'upporting'wheel and a ratchet wheel on Said shaft, an operating handle assembly pivoted on said hous` ingaV handle pawl pivotally supported on said handle as'- sembly, means biasing said handle pawl into ratcheting position, said last mentioned means comprising cooperan--` ing detent elements carried by said handle assembly and said handle* pawl deiining a first detent position for said handle pawl wherein said pawl is in ratchet engaging position, cooperating detent means carried by said handle pawl and said handle assembly defining a second detent position for saidhandle pawl wherein said handle pawl is disengagedy from said ratchet wheel, means carried by said housing adapted to engage said load'pawl at one extreme portion of a load lowering stroke of said handle assembly to thereby displace said' handle pawl into said seconddetent position, and a member carried by said housing `adapted to engage said handle pawl at the' other extreme portion of a load lowering stroke to displace said-handle pawl into said first detent position.

ReferencesCitedin the le of this patent UNITED STATES PATENTS 367,513 Glenn Apg. 2, 1837 1,667,864 Maley a May l, `19248 2,841,035 Simpson July 1, 1958 2,854,852 Clark Oct. 7, 19.5.8