US1288989A - Lifting-jack. - Google Patents

Description

J. W. REES.

LIFTING JACK.

APPLICATION FILED APR. I3. 1916.

1,288,989, Patented 1m. 24, 1918.

2 SHEETSSHEET I.

2 1 52 men for:

(Jesse WZPees.

J. W. REES.

LIFTING JACK.

APPucATwN FILED APR. I3, 1916.

1 ,288,989 Patented Dec. 24, 1918.

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JESSE W. REES, OF ST. PAUL, MINNESOTA.

LIFTING-JACK.

Specification of Letters Patent.

Patented Dec. 24, 1918.

Application filed April 13, 1916. Serial No. 90,959.

To all whom it may concern:

Be it known that I, Jnssn W. REES, a citizen of the United States, residing at 1 St. Paul, in the county of Ramsey and State of Minnesota, have invented a new and useful Improvement in Lifting-Jacks, f which the following is a specification.

An object of my invention is the production of a lifting jack of that character which is portable and adapted for lifting heavy loads with little manual effort. This invention relates to that general class of lifting jacks set forth in Patent Number 1,172,832. granted to me on the 22nd day of February, 1915. In this application the jack member is formed with a head which is movable vertically in a suitable holder or base. A par ticular advantage attained by this invention is the application of power equally and symmetrically on opposite sides of the rack member, and in providing a guiding surface which cooperates with the means for applying power, whereby resistance is reduced in applying a lifting effort.

WVith these objects in view together with others which will appear from the following description, my invention comprises the features of construction and combination of parts hereinafter more particularly described and claimed.

In the accompanying drawings forming part of this specification, Figure 1 is a side elevation of my invention, parts thereof being broken away and in section for the purpose of illustrating the construction; Fig. 2 is another side elevation f the construction illustrated in Fig. 1, parts thereof also being broken and in section; Fig. 3 is a side elevation of an alternative construction of my invention, part of the base being broken away and in section and the cover plate re moved; Fig. & is a section taken upon the line XX of Fig. 3, and Fig. 5 is a section taken upon the line Y-Y of Fig. 3, with the ratchet member removed.

In the following description the simplest embodiment of my invention as disclosed in Figs. 1 and 2 will be first described following which description the construction illustrated in Figs. 3 to 5 will be set forth. My invention is composed of two main ele ments, A indicating in the drawings the housing Or stationary holder constituting one of said elements, and B the lifting head, which constitutes the other element. The housing A is of suitable shape to form a holder in which the lifting head member and its immediately cooperating parts are held, the lower portion of said housing being formed with a Hat base plate 2 which is adapted to stand firmly upon the ground or other support to form a stability base for the device. The head B is in the form of a solid cylinder or thrust shaft sliding-vertically in a passage 3 in the upper end of the housing, said cylinder carrying a bifurcated shank 4. Each of the members 5 .and 6 constituting said bifurcations, consists of a double rack having oppositely arranged toothed members '7 and 8. Said bifurcations are on opposite sides of a vertical channel 13. The oppositely disposed sets of teeth on each bifurcation or double rack member are adapted to mesh with the teeth of pairs of pinions 9 and 10, there being two pinions 9 and 10 disposed on each side of said shank, one-set meshing with the teeth of therack member 5 on one'side and the other set with the teeth of the rack member of the opposite side, so that as the pinions are revolved in opposite directions simultaneously, the head is either raised or lowered. Each pair of said pinions is 0 formed integral with an intermediate worm gear 11 and also with gudgeons 12 extending outwardly endwise from both pinions of a pair. A worm gear 11, pinions 9 and 10 and gudgeons 12 of each unit consequently turn together. The channel 13 which is formed between the pairs of vertical racks of the bifurcations 5 and 6 admits the worm gears 11-11 to project inwardly allowing the teeth of the pinions 99 and 1010 to mesh freely with therack members of each of said bifurcations. The housing is formed with journal supports 1% in which the gudgeons 12 are j ournaled and turn freely and said housing is als shaped with enlargements 15 which are designed to accommodate the gears freely and protect them from dust and dirt within the structure. Extending across the housing through the channel 13 and journaled in supports 16 formed on the housing is a drive shaft 17, which carries a pair of right and left handed worm pinions 18 and 19, the teeth of which mesh with the teeth of the worm gears 11-11 and serve to drive said worm gears and assist in transmitting rotary motion from the drive shaft to the reciprocatingrack members carried by the head member B. One end of the shaft 17 extends outwardly from the housing, and has connected thereto a ratchet wheel 20, which is operated by a spring pressed pawl member 21 and a lever receiving socket 22, the latter member being freely journaled upon said shaft over the ratchet wheel, whereby as 'the socket 22 is swung up and down, the

pawl member engages the ratchet wheel and turns the shaft in a similar manner to devices of this character, which are in common use.

The upper portion of the housing is provided with a bail 23, by which the device can be carried from place to place and arranged with the head member B below an object to be lifted. The housing 1s split and made in two parts secured together by bolts 2a or any other suitable means to enalble assembling the mechanism and packing with grease or oil. Shoulders 25 at the upper ends of the bifurcations are adapted to limit the upward movement of the lifting head by striking the stop 26 formed at the lower end by the guiding portion of the housing in which the head slides.

In use the jack is employed 1n the usual manner, the head being set below an ob ect to be lifted. The lever socket member 22 is then swung up and down turning the shaft 17 step by step and transmitting a powerful lifting movement to the lifting head.

The application of power on opposite sides of the rack member and of the sliding contact surface on the housing at the upper end of the head distributes a guiding support for the lifting element evenly at three points whereby resistance in lifting a load is reduced to a minimum.

The parts will remain immovable by the load at all points automatically. To return the headinto lowered position the ratchet mechanism is reversed and the lever socket member again reciprocated. The symmetrical application of a lifting movement on all sides of the lifting head member reduces friction and prevents any binding or pinching tendency between the parts and the com bination of gears employed multiplies power very materially.

In the construction illustrated in Figs. 3 to 5 inclusive, the design of housing employed is slightly modified over the con- I struction illustrated in Figs. 1 and 2. The essential elements of my invention, however, are all present only differently arranged. The head member is caused to slide in a vertical passage 30, which is formed in the base member and the head member is not necessarily bifurcated, a single pair of rack members 31 and 32 being formed on the opposite sides of its shank. The teeth of the rack members are engaged by the teeth of a pair of oppositely disposed pinions 33 and 34:, each of said pinions being formed integral with a shaft 35 journaled in the base member. One end of each of the shafts 35 carries a worm gear 36, the teeth of which mesh with the teeth of two oppositely pitched worm pinions 37 and 38 on the shaft 39. The worm pinions 37 and 38 are carried by a single countershaft 39, which is journaled in the base element in horizontal position and revolved forwardly or backwardly by the ratchet mechanism 40 carried by the lever engaging member 41. A portion of the base member forming a housing over the gearing is split and removably attached by the bolts 42 or other suitable means, whereby the casing containing the gearing may be easily packed with grease or oil for lubricating the parts.

In use the jack is operated in substantially the same manner as above described, a powerful lifting movement being imparted to the lifting element by the combination of parts cooperating together in the manner set forth. For the purpose of engaging an object close to the lower end of the base, a projecting lug 4:3 is formed on the lower end of the lifting element, which extends through and slides in a vertical slot a l in the side wall of the base element.

The application of power on the opposite sides of the rack member and of the sliding contact between the upper portion of the housing at the upper end of the lifting member and the advantages accruing therefrom are the same in the alternative construction as in the preferred.

In accordance with the patent statutes, I have described the principles of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the construction shown is only illustrative and that the invention can be carried out by other means and applied to uses other than those above set forth within the scope of the following claims.

Having described my invention, what I claim as new and desire to protect by Let ters Patent is:

'1. A lifting jack, comprising, in combination, a housing having a short vertical passage through its upper end, a substantially horizontal shaft journaled in and projecting from said housing, gear mechanism adapted to be driven by said shaft, a lifting head having a substantially vertical shank slidably supported in said passage and formed with a double set of rack teeth disposed on its opposite sides, each of said sets of rack teeth being adapted to mesh with said gear mechanism to engage therewith simultaneously and guide said shank at two opposite points below and substantially centrally above, said points being distributed evenly to reduce friction.

2. A lifting jack, comprising, a housing, a lifting element projecting through and guided by the upper end of said housing and depending freely, and having a double set of rack teeth disposed on opposite sides thereof, a pair of gear elements with which the teeth on the opposite sides of said rack mesh and by which the lower end of said lifting element is guided, each of said gear elements comprising a gear having teeth in mesh with the teeth of the adjacent set of rack teeth, and a spiral drive gear, and a drive shaft journaled in said base having opposite threaded worm teeth in mesh with the teeth of said driving spiral gears, the contact points between said lifting element and gearing being arranged whereby the lifting element is guided at three distinct contact points equally distributed and isolated apart to reduce binding tendency of said parts to a minimum.

3. A lifting jack, comprising, in combination, a housing having a gear casing at one side and a short passage through its upper end, a substantially horizontal shaft journaled in said gear casing, gear mechanism in said casing and housing adapted to be driven by said shaft, a lifting head having a substantially vertical shank slidable through said passage and formed with sets of rack teeth disposed on opposite sides, each of said sets of teeth being adapted to mesh with a portion of said gear mechanism in said housing to engage therewith simultaneously; said shank being guided at two opposite points below by said gear mechanism and at substantially one centrally above formed by the side of said passage, said points being distributed evenly to reduce friction.

In testimony whereof, I have signed my name to this specification.

JESSE W. REES.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

- Washington, D. 0.

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