US1674397A

US1674397A - Lifting jack

Info

Publication number: US1674397A
Application number: US184008A
Authority: US
Inventors: Arthur C Hopkins
Original assignee: National Standard Co
Current assignee: National Standard Co
Priority date: 1927-04-15
Filing date: 1927-04-15
Publication date: 1928-06-19
Anticipated expiration: 1945-06-19

Description

June 19, 1928. 1,674,397

' A. C. HOPKINS LIFTING JACK Filed April 15, 1927 2 Sheets-Sheet 1 INVENTOR m 2 @wmwe A TTURNE VJ June 19, 1928.

A. C. HOPKINS LIFTING JACK Filed April 15, 1927 2 Sheets-Sheet 2 INVENTOR ir/fior C. HOP/r076 A TTORNE Ys Patented June 19, 1928.

UNl'FE D STATES PATENT @FFICE.

1 :AETHIUR Gfl-HQPKINS; MICHIGAN, ASSIGNOR TO NATIONAL-STANDARD COM- PANY, OF RIFLES- .JlrIICI-IIGAN.

LIFTING JACK,

Application filed April 15,v

powerful.

Second, to provide an improved lifting jack having friction clutch actuating means in which: theclutch is easily released and at the same time not likely to slip.

Third, to provide an improved lifting aekhaving these advantages which may be rapidly lowered, at the same time the lowering is under the control of the operator.

Objectsi'elatin'g to details and economies of construction and operation of my 11)Vt 31'! tion will appear from the detailed description to follow.

The invention is defined and pointed out" in the claims.

A structure which is a preferred embodiment of my invention is illustrated in the' accompanying drawing, .forming a part of this specification, inwhich:

Fig. 1 is a perspective viewof a lifting jack embodying the features of my. invention.

Fig. 1 is adetail perspective view of the outer portion of the actuating lever.

Fig. 2 is a detailview partially in section?" on line 2-2 of Figs. 3; and 4, showing struc tural details.

Fig. 3 is a detail section on line 33 of Fig.

4 a detail section on line 4L of Fig 1 In the drawing si'milar reference characters refer to similar parts throughout the several views.

. Referring to the drawings, the structure il'- lustrated comprises a frame consisting of

side members

1, 1 connected in spacedrelation by suitablecross members. At its rear end, the frame provided with an axle 2 for the supportingwheels 3. At the front end of the frame are. laterally projecting brackets 4 on which the caster'wheels v5 are mounted.

The lifting lever 6 is .pivotally mounted on the cross rod 7 extending between the side members.

The head 8 is it-iountedon the pivot 9 on the outer end of the lifting lever. Alink 10 is connected to the head member by the pivot 11 and to theframe by the pivot 12,

the link being disposed in parallel'relation 1927. Serial No. 184,008.

" to the'lifting lever so that as the lifting leveil? is swung on its pivotg the head is'kept in" an upright position.

A- pair of racks 13 are connected to the lifting lever at 14' in spaced relation to the lever pivot 7. These racks are supported by rollers 151onthe frame cross member 16 so that the racks coact with the elongated pinion" 17 having journals 18 in its ends supported on the frame and bearings formed on the brackets 4. On this-*pinion is a clutch drum 19am also a holding ratchet 20. For

convenience in-nianufature, the drum and ratchet are broached to receivethe elongated pinion.

' I providea clutch member designated gen erally by the numeral 21' and having an annular clutch shoe 22, split at the shoe having a lining or facing designated by the numeral 24. 'lhe actuating lever 25 is pivoted at 26 on thisclutch- 'inniber-and provided with a thrust member" 27 engaging the clutch shoe 22adjacent the split therein. This thrust member is arranged close to the pivot 26 so that by pressing down upon the lever, a very powerful leverage is secured to closetheclutch. 2'

v A spring 28 is seated in a holder 29 on the clutch member to engage the actuating lever 25 at the rear of its pivot 26, as shown inflFig. 3, the spring acting to normally engage the clutch or to urge its shoe to en gag ng position.

An upward, lift, however, on the lever swings the thrust member away from the shoe, thereby releasing t-he'clntching pressure.

: To hold the clutch against rotation and thereby prevent this releasing. operation, I provide the clutch member with a segmental rack 30 with which a, reversing pawl 31 coacts, [this reversing pawl being normally held ininoperative position, as shown in Fig. 3. The holding pawl 32 coacts with the holding ratchet 20, being held normally in engagement therewithby' the spring 33,

this spring acting also to hold the.pawl 31 out of engagement.

In the lifting. operation, the lever 25 is oscillated to release the clutch and. allow it toswing around the drum for a new grip, the clutch being released merely by an upward lift on the lever andcngaged by a downward thrust thereon. Continued downward thrust rotates the drum which is held against backward rotation by the nolding pawl coacting with the lever. hen it is desired to lower the lifting member, the reversing member 34, which is in the forni of an annular rack mounted on the shoulder 35 of the ratchet, is actuated to disengage the holding pawl and engage the reversing pawl.

This reversing member 34 is provided wit-

h arms

36 and 37, the arm 36 carrying a rod 38 which is pivoted at 39 to the arm, the rod being slidably engaged with the lug 40 on the pawl 31. A coiled spring 41 is arranged between the lug and the shoulder 42 on the rod so that as the reversing member is rotated, the thrust of the spring acts to yieldingly urge the pawl 31 into engagement with the rack 30, at the same time the holding pawl 32 is released. This pawl is connected to the arm 37 by means of the rod 43 which is pivoted to the arm 37 at 44, the rod being slidable through a lug 45 on the pawl, a spring 46 being arranged between the lug 45 and the thrust collar 47 so that as the member 34 is rotated, the engagement of the pawls is reversed.

When the pawl 31 is engaged, the rotation of the clutch member is prevented. thereby allowing a releasing of the clutch by lifting upwardly on the lever 25, and if desired, the amount of slipping friction necessary can be maintained to allow the slow return of the lifting lever.

The reversing member is actuated by a dog 48 which is pivoted at 49 on the link 50. This dog has a rearwardly extending tail 51 to which the control rod 52 is connected. A spring 53 is connected to the dog at 54 and to the clutch member at 55, so that by pulling on the control rod, the first action is to swing the dog on its pivot49, bringing the lug 56 into engagement with the rack of the reversing member 34; continued pull on the rod rotating the rack, and thereby engaging the reversing pawl and releasing the hold:

ing pawl.

The control rod is provided with a hand piece 57 adjacent the hand piece 58 of the lever so that the hand pieces may be simultaneously grasped versed and quickly lowered, the lowering being under the control of the operator. 7

I have illustrated and described my improvements in an embodiment which I have found very practical. I have not attempted to illustrate or describe certain modifications or adaptationswhich I contemplate as I believe this disclosure will enable those skilled in the art to embody or adapt my improvements as may be desired.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a lifting jack, the combination of a frame, a lifting member, a drum operatively connected to said lifting member, a clutch member provided with a rack and with a clutch shoe coacting with said drum, an actusting lever pivoted on said clutch member to coact with said clutch shoe, a spring acting to normally urge the clutch shoe to engaging position, a holding ratchet connected to said drum, a holding pawl coacting with said holding ratchet, a reversing pawl coacting with said rack on said clutch member, a rotatably mounted reversing member provided with a rack and with radially disposed arms, rods pivoted to said arms on said reversing member, said pawls being provided with lugs with which said rods are slidably engaged, springs arranged on said rods and acting to release the holdingpawl and engage the reversing pawl on the actuation of said reversing member, a reversing member actuating dog, a supporting link for said dog, a spring acting to hold said dog normally in disengaged position, and a control rod connected to said dog whereby a pull will first engage the dog with the reversing member and a continued pull will actuate the same.

2. In a. lifting jack, the con'ibinaticn of a frame, a lifting member, a drum operatively connected to said lifting member, a clutch member provided with a rack and with a clutch shoe coacting with said drum, an actuating lever pivoted on said clutch member to coact with said clutch shoe, a spring acting to normally urgethe clutch shoe to engaging position, a holding ratchet connected to said drum, a holding pawl coacting with said holding ratchet, a revere ing pawl coacting with said rack on said clutch member, a rotatably mounted revers ing member provided with radially disposed arms, rods pivoted to said arms on said reversing member, said pawls being provided with lugs with which said rods are slidably engaged, and springs arranged on said rods and acting to release the holding pawl and engage the reversing pawl on the actuation of said reversing member.

3. In a lifting jack, the combination of a frame, a lifting member, a drum operatively connected to said lifting member, a clutch member provided with a rack and with a clutch shoe coacting with said drum, an actuating lever pivoted on said clutch member to coact with said clutch shoe, a spring acting to normally urge the clutch shoe to engaging position, a holding ratchet connected to said drum. a holding pawl coacting with said holding ratchet, a reversing pawl coacting with said rack on said clutch member, a rotatably mounted reversing member provided with a rack and with raditit) ally disposed arms, a rwrersing member ac tuating dog. a su n iort ug 'i l; for said d a spring acting to hold said dog iltiliiilillv in disengaged position, and a control rod connected to s: id dog wher bv a poli will first engage the dog w ith 2h revcr her and a continued pull will actuate th same.

4. In a lifting: iaclr. th combination f a frame, a lifting member, 'lrnni operatiw l v connected to said lift ng membe a cl t h Il'lOl'llllGl provided with a incl: and with a clutch shoe ena t ng with r-nid drum. an n"- tuating lever pivoted on aid hdc'n w mbto enact with said clutch shoe, a :-=pring a iing to norinnliv urge the clutch sl engaging posit on. a holding ratchet onnect to said drum. a holding pawl coa ting' v, said holding rat het. a reversing pawl coacting with said rack on said clutch llit:.-'!- her, and a rotatably mounted r versing menu ber provided with radiallv dispo d arm;

5. In a lifting jaclt. the combination of a frame, a liftin T membe a drum op rzul've ly connected to raid lifting member. a l"llii"il member provided with racl: and with a clutch shoe coactiing with said drum, an actuating lever pivoted on said cluiwh iiltil" her to oact' with said clut h shoe. :1 spring acting to normally urge the clutch shoe engaging position, a holding ratchet coir nected to said drum. a hwlding pawl oaciing with said holding ratchet, a rcver iug pawl coacting with said rack on said clut h member, a rotatably mounted rcver inzs member provided with a l'tl('l\' operativel v associated witl s id pawl to release the holding pawl and eng" are the reversing pawl on th* actuation of said reversing il'ltm f. a reversing member ctuating do porting linl; for said dog. a spr to h ld said dog normally in disengzr sition. and a control iod conne ted to sa d dog whereb} a pull with the reversing member and a continued pull will actuate the aaiiie.

ti. In a lifting jaclt. the com ination of a frame. a lifting member, a drum operativelv connected to said lifting member. a clutch member provided with a rack and with a. clutch shoe coacting with said drum. an actuating lever pivotcd on said clutch 1nem bcr to enact with said clutch shoe. :1 sprina' acting to normall'a urge the clutch shoe to engaging position. a holding ratchet connected to said drum. a holding pawl coacting with said holding ratchet. a reversing pawl coacting with said rack on said clutch member. and a rever ing member provided with a rack operativelv associated with aid pawl.

T. In a lifting jack. the combination of a frame. a lifting member. a drum operativelv connected to said lifting member. a clutch member provided with a rack and with a n in will tir t engage th dog clutch shoe coacting with said drum, an actuating lever pivoted on said clutch member to coact with said clutch shoe, a holding ratchet connected to said drum, a holding pawl com-ting with said holding ratchet, a reversing pawl coacting with said rack on said clutch member, a rotatably mounted reversing member provided with a rack and operatively connected to said pawls whereby the holding pawl is released and the reversing pawl engaged on the actuation of said reversing member, a reversing member actuating dog, a supporting link for said dog. a spring acting to hold said dog nor mally in disengaged position, and a control rod connected to said dog whereby a pull will first engage the dog with the reversing member and a continued pull will actuate the same.

8. In a lifting jack, the combination of a frame. a lifting member, a drum operativel v connected to said lifting member. a clutch member provided with a rack and with a clutch shoe coacting with said drum, an actuating lever pivoted on said clutch member to coa t with said clutch shoe, a holding ratchet connected to said drum, a holdin pawl coacting with said holding ratchet, a reveiudng pawl coacting with said rack on said clutch member, and a reversing member operativelv connected to Said pawls v-Jhercby the holding pawl is released and the reversing pawl engaged on the actuation of said reversing member.

5). in a lifting jack, the combination of a frame, a lifting member pivotally mounted on said frame, a pair of rack bars pivotally connected to said lifting member in spaced relation to its pivot, an elongated pinion coacting with said rack bars, a drum on said pinion, a clutch member provided with a racl; and with an annular split clutch shoe coacting with said drum, an actuating lever pivoted on said clutch member to coact with one end of said clutch shoe. a spring interposed between the opposite end of said clutch shoe and said lever and acting to normall v urge the clutch shoe to engaging position, a holding ratchet connected to said pinion. a holding pawl mounted on said frame to coaci with said holding ratchet, a reversing pawl mounted on aid frame to coact with said ra l; on said clutch member, and a reversing member operativcly associated with said pawls.

ll. ln a lifting jack. the combination of a frame. a lifting member pivotally mounted on said frame. a pair of raci: bars pivotally connected to said lifting member in spaced relation to its pivot, an elongated pinion coacting with said rack bars. a drum on said pinion, a clutch men'iber provided. with a rack and with an annular split clutch shoe coacting with said drum, an actuating lever pivoted on said clutch member to coact with said clutch shoe, a holding ratchet connected to said pinion, a holding pawl mounted on said frame to coact with said holding ratchet, a reversing pawl mounted on said frame to coact with said rack on said clutch member, and a reversing member operatively associated with said pawls.

11. In a lifting jack, the combination of a frame, a lifting member pivotally mounted on said frame, a rack bar pivotally connected to said lifting member in spaced relation to its pivot, a pinion coacting with said rack bar, a drum connected to said pinion, a clutch member provided with a rack and with an annular split clutch shoe enacting with said drum, an actuating lever pivoted on said clutch member to coaet with one end of said clutch shoe, a spring interposed between the opposite end of said clutch shoe and said lever and acting to normally urge the clutch shoe to engaging position. a holding ratchet connected to said pinion, a holding pawl mounted on said frame to coact with said holding ratchet, a reversing pawl mounted on said frame to coact with said rack on said clutch member. and a reversing member operatively connected to said pawls whereby the holding pawl is released and the reversing pawl engaged on the actuation of said reversing member.

12. In a lifting jack, the combination of a frame, a lifting men'iber pivotally mounted on said frame, a rack bar pivotally connected to said lifting member in spaced relation to its pivot, a pinion enacting with said rack bar, a drum connected to said pinion, a clutch member provided with a rack and with an annular split clutch shoe coacting with said drum, an actuating lever pivoted on said clutch member to coact with said clutch shoe. a holding ratchet connected to said pinion. a holding pawl mounted on said frame to coact with said holding ratchet, a reversing pawl mounted on said frame to coact with said rack on said clutch member, and a reversing member operativclv connected to said pawls whereby the holding pawl is released and the reversing pawl engaged on the actuation of said reversing member.

13. In a lifting jack. the combination of a frame, lifting member. a drum operativelv connected to said lifting member. a clutch member provided with a rack and with a clutch shoe coacting with said drum, an actuating lever pivoted on said clutch member to coact with said clutch shoe, a spring acting to normally ur 'e the clutch shoe to engaging position, a houling ratchet connected to said drum. a holding pawl coacting with said holding ratchet. a reversing pawl. coacting with said rack on said clutch member. and a reversing member operatively connected to said pawls to release the holding pawl and engage the reversing pawl on the actuation of said rcversing member.

14. In a lifting jack, the combination of a frame. a lifting member. a drum operatively connected to said lifting member, a clutch member provided with a clutch shoe coacting with said drum, an actuating lever pivoted on said clutch member to coact with said clutch shoe, a holding ratchet connected to said drum, a holding pawl coacting with said holding ratchet, :1 reversing pawl coacting with said clutch member, and a reversing member operatively connected to said pawls to release the holding pawl and ei'igagc the reversing pawl on the actuation of said reversing member.

15. ln a lifting jack, the combination of a f ame. a lifting member, a drum operatively connected to said lifting member, a clutch member coacting with said drum, an actuating lever operatively associated with said clutch member, a holding pawl for said drum, means operativclv associated with said clutch, permitting the releasing of the clutch by manipulation of said actuating lever, and means for actuating such releas ing means operatively connected to said holding pawl whereby the holding pawl and said releasing means are alternately engaged and disengaged.

16. In a lifting jack, the combination of a frame a lifting member. a drum operativelv connected to said lifting member, a clutch member coacting with said drum, an actuating lever operativclv associated with said clutch member. a holding means, clutch releasing means, and means for actuating such releasing means operativelv connected to said holding means hercbv the holding means and said releasing means are alternately engaged and disengaged.

In witness whereof I have hereunto set my hand.

ARTHITR C. HOPKINS.