US1339377A - Ratchet-jack - Google Patents

Description

JfiC. KORE. RATGHEI JACK.

APPLICATION FILED NOV. 4,1919.

Patented May 4, 1920.

ZSHEETS-SHEET I.

f NVENTOR 4 MG K ATTORNEY J. C. KOPF.

RATCHET JACK.

'APPLICAHON mnyuov. 4. I919.

1,339,377. e ted ay 4, 1920.

, 2 SHEETS-SHEET 2- ATTORNEY l Inn srirrns PAlZENT orricn.

Wmmw

EQHN G K6391, Cl BELLEVUE, EENNSYLVANIA, .ASSIGNGR TO THE DUFF MANUFAC- TURING CGMPAIIIY, 0F PITTSBURGH, lENNSYIJTANIA, A CORPORATION OF rsnnsrnvarrrs.

RATGZIETJAGK.

Application filed November t, 1919.

To all whom may concern:

Be it known that- I, Join: Kori", a citizens of the United States, and resident of the borough of Bellevue, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Ratchet-Jack, o l which the following is a specification. v

The invention is an improvement in ratchetjacks, that is to say, jacks having ratchet teeth on their sliding bars, and pivoted holding and lifting pawls, the latter moved by the operating lever, and reversing means whercbythe action of the pawls can be changed from that of raising to that of lowering, and viceversa. The particular type of ratchet mechanisin upon and within which the prescnt-invention is an improvement is disclosed in the Hindrnan Patent 1,093,269 of April 14-, 1.914, whereina single spring forms a connection betwcen the pawls, acting as a floating formed with two outwardly extending loops adjacent the pawl pins and with a central inwardly extending loop, the spring thus comprising a species of Zig-Zag or W hibiting narrow bends and distinct lobes,

the purpose of which was to secure the necessary stretch and contraction in the different operations. The central loop also served to cooperate with the reversing means, which comprised two parts, a secondary lever pivoted below the spring and having a finger movable forwardly and rearwardly into and out of the loop, and a reversing and locking hand lever having a nose in camining relation to the secondary lever and adapted to seat in a holding notch therein. In practice it was found that still. more elasticity could be obtained by inching the spring of round Wire instead. of flat material, coiling the back of the bottom loop in. plurality of convolutions. l vhile the mechanism was effective author admirable simplicity, it developed that in time the set of the spring was likely to alter, after which the pawls Would not act properly f ljyw g n Specification of Letters Patent.

Patented May 4, 1920.

Serial no. season ing dog"; while ii the spring" he a little too" short will not be compressed enough on the downstrolre oi the lever to move and keep the bidding pawl out of engagement while the lifting; pawl takes hold again and,

after first slightly raising the bar, starts to lower it another step. In the first case the bar will be simply oscillated up and down in place, the lifting pawl continuing toact on the same tooth; in the other case the lifting pawl will move idly up and down the bar, the holding pawl always catching under one tooth. Diiliculty was also encountered with the springs breaking, due, I believe, to local- 1 ization of bending strain, to a lesser aptitude of the narrow loops for opening than for closing, and to crystallization at the end of the central loops where it Worked against the finger of the reversing mechanism in raising.

l find that a much more durable and elli- (-ient spring can be produced by returning to the band style with a different configuration, combined with which I also provide a simpler reversing means consistingof a reversing and locking hand lever cooperative directly with the single spring. Said spring 1s in t e nature of an. open bow, havin a substantially plain or, continuous back, with, preferably, a shallow holding notch at the middle, for cooperation with the nose of the reversing, lever. Such. a spring avoids the sharp bends and narrow loops of the other forms, is unitary rather than subdivided,

and its action is more distributed, whereby it is less likely to lose its set or become broken, and at the same time it has ample capacity for flexing, to pull and push upon its moving abutinents. in addition, its full back is adapted for coaction with a single reversing lever, the pivofal axis of which is behind the spring, in order that its nose may operate thereon with a wiping or ca nming action. to be locked at the approximately perpendicular position, Where it snaps into the notch. v

in the-accompanying drawings, forming :1 part hereof;

. curve {39, and is curled over Figure .l is'a. side elevation of the jack, with the side cover removed, and. the mechanism in condition for-raising; and

Figs. 2 and 3 are schematic side views of the mechanism, illustrating different stages of the lowering operation, the reversing lever being in its idle position.

The jock stand 2 and its base 3 may be made in two halves, united by rivets 40 passing through marginal flanges 24, 28, 3 0 and 32. The rack-bar L1 is provided on ts inner. edge with. downwardly facing ratchet teeth 42., and has 9. head 1-3, and itdesired an external toe-lift bar 44 notched city l4" to support adjustable toe-lift 4.6.

The pawl mechanism is contained within a pawl chamber 6 at the back of the stand, said-chamber having a window 7. for access. A cover, not shown, is applied over the open side of the pawl case and is secured by screws to the openings 8 and 9.

The operating lover or rocker 4:9,socketed for the. reception of a removable handle, is

'lr'ulcruined in the pawl chamber on a rivet 39. Piyoted on its forward end at 50. closely adjacent the rock, is the lifting pawl 51.. The holding pawl 52 1s pivoted on a rivet 38, higher up and further away from the rack, in overlapping relation to the lifting pawl, the holding pawl thus being mounted on a fixed axis, while the lifting powl is movable up and down between the holding pewliand the rack. At their inter- .mediate portions, and somewhat nearer their free ends than their pivotal ends, the vpawls beer studs or pins 5:.) and 54, which project outward. from the pawl chamber, througl'i the window 7, into the cover chomher 12, at the opposite side of thewall (l. l-Iere their end. are appropriately reduced to receive the curled ends of u spring 56, the

spring being held in place by cotter-pins 57 passed through trzmsverse openings in the ends of the studs.

Said spring is made of band or strip inuteriul, and has a special conformation, which may be described generally as an open bow. its back 58 is oll'sct reurwordly from its ends by curves 59, 64) and is substantially full or continuous, as distinguished from the angled or subdivided form of the patent referred to. .t its approximate middle there is preferably a shallow, curved holding notch .61. As best constructed, the spring rises from the inner side of the upper terminal eye, and

arches rearward over the stud '54, forming the curve 60, thence extendssubstantially straight downward, forming the back, then swings under and forward in the broader und'around the stud 53.

A. single reversinp and locking levery62 pivoted on the fixed stud 1.5, whiclf'is l0- outed behind the spring, and is held in place by a cotter-pin. 63. The rear portion of this lever constitutes a handle, passing outward through a slot in the haul-z of the cover ll, end its short forward arm or nose 64: is formed to ride upon the heclr of the spring, and tosnap, in the perpendicular position, into the notch 61. wherewith it forms an inn positive lock.

in this condition, which is the lifting condition, the spring is held or pressed at the middle, so that its upper and lower portions, noting independently, cause both pawls to the ratchet at all times. During such operation there is ample amoniniodation in the broad lower-curve 5f) tor. the up and down movements of the lifting pawl, this part of the spring rolling back and. forth in a manner best calculated I to preserve its original elasticity. The upper part of the spring has only to yield to the slight move-- ment of-l'he holding; pawl, which at its tip is only the width of a ratchet tooth face,

end at the stud 54 considerably less; and

this flexing, is distributed between the "arch (30, which slightly opens and closes, and the upper part of. thel'liack portion, At the middle of the sprinir, where the shallow curved notch bears on the rounded nose of, the reversing, lever there is no destructive or fatiguing" notion.

For lowering, the handle portion of the reversing'lever is pushed downward, free? Ill ing its nose from the notch, and disposing it clear of the spring, as seen in Figs. 3 and 4. The spring is now floating, and acts as a unit, first in compression and then in ten sion, according to the positions of the pawls. The general operation is the some as in the Hindman patent aforesaid. ()n the upstroke of the handle, the ratchet nor is lowered a tooth by the lifting dog, and during this .rnovement the" teiisioning of the spring pulls the holding dog beneath a ratchet tooth one higher than it engaged previously.

When the rack settles full upon the holding,

dog, the lifting dog is relieved of its load, and the spring still under tension pulls it out; On the succeeding \ilownstroke of the lever, the lifting dogis pushed upward free of the ruck, thereby compressing the s pring',

which causes it to move inward bone, h the next tooth above. lhu'thermoveznent raises the rack slightly, and the lifting pawl is freed and pushed out by the spring. As the timing of the pa-wls is governedwhol-ly by the spring and the leeway in either'direction is inconsiderehle, the spring will function properly only so long as its elasticity remains substantially unchanged, and'this the present invention aims to secure for the muxiinuin period, as well as guarding against breakage, heretofore stated. \Vith the spring constructed. as described, it will be perceived that the strains in the lowering operation ere comparatively mild, and

are not concentrated at any point weeks ness but are Well distributed. A cam 65 on the inner side of theholding pawl serves to assist the spring in guiding the lifting pawl to its proper engagement with the ratchet, and its presence also compels the disengagement of the holding pawl, if there should be any reluctance in its movement. The rearward movement of this pawl is limited by a fixed shoulder 66 in the back of the pawl case.

"What I claim as new is:

1. A ratchet-jack mechanism of the typ comprising a lifting pawl, a holding pawl, a single band spring connecting said pawls acting alternately in tension and compression in lowering, and reversing means adapted to bear upon the approximate middle of the'back of the spring for raising, characterized by said spring being an open bow with the intermediate portion of its back.

rear-wardly disposed for cooperation with the reversing means.

2. In a ratchet-jack, the combination with a holding pawl and a lifting pawl, of a single band spring connected at its ends to said pawls and bowed rearwardly with a sub stantially continuous back, and a reversing hand lever having its pivot behind theintermediate portion of the backand its nose arran ed for direct camming action thereon;

3. he combination with a ratchet-bar,

holding pawl, and an operating lever with a lifting pawl pivoted thereon, of a single spring connecting said pawls acting alternately in compression and tension for lowering, and a reversing and locking hand leback, and a reversing and holding lever pivoted behind the spring.

5. In a ratchet-jack mechanism having holding and lifting pawls with pins, and a reversing lever, a single band spring connected at its ends with said pawls and presenting its back to said reversing lever. saidspring having its ends curled around said pins, upper and lower portions'curved rearward away from the pins, the lower curve being relatively wide, and a substantially continuous back.

JOHN C. KOPF.

Images