US1786866A - Jack - Google Patents

Description

15:21:,30, 1930. c. J. RODMAN I JACK 7 Filed June 9 1926 2 Sheets-Sheet 1 c ISIYENTOR 25w Dec. 30, 1930., RODMAN 1,786,866

INVENTOR Patented Dec. 30, 1936 RICE 3'. BGDEAN, OE ALLIANCE, 0BR) JAGK Application filed runs a, was. Serial No. 114,682.

This invention relates to lifting jacks and is particularly useful in connection with jacks used for automotive vehicles, although my invention has numerous other applications.

5 Jacks of the screw type as heretofore constructed have been open to numerous disadvantages. It the jack is to be operated by an extended handle or in. fact by any other method the screw or lift portion of the jack 1 generally tends to turn until it is in actual engagement with the article to be lifted and this makes the initial setting of the jack a dificult and disagreeable operation. it has been necessary to make a screw of very large size in order to secure adequate stifiness although a smaller screw would be satisfactory so far as direct lifting is concerned. Even with a screw of large size bending is frequently encrmntered especially when the jack invariably. This tendency may be occasioned in part by the fact that when it is applied to an automobile axle the-car in efiect is rotated'about the other axle so that the axle which is beingliited does not rise in a straieht line but rises on the arc of a circle thus tending to shift the point of engagement of the jaclr relative to its supporting base. The same diiiiculty is caused by uneven footings for the jack, such as are encountered in an ordinar road bed.

I provide a jack having a base anda relatively movable litter which is preferably provi ed. with an improved form of gui e and a cooperating screw and nut for causing relative vmovement between the base and the lifter. this construction the screw may be made materially smaller without any sacriiice in strength since it is utilized solely tor providing vertical or lifting force, the

, lifter being guided in the post elements so that there is no possibility of twisting or bending of the screw, and therefore a smoother operating jack is secured.

Preferably the base isprovided with a post having a vertically extendin' slot therein and the screw is located in this slot. Guide means are provided for the lifter along the edge of the'slot and an extension is provided is working near top limit, and binding be-c the screw and the nut occurs almost on the lifter. This extension fits into the slot and is secured to the bottom end of the screw. The top end of the screw is fastened with the screw thus fastened at the top and bottom a material improvement in strength and in operating conditions is secured.

The lifter is preferably' so formed that it almost completely surrounds the screw and thus protects it from abuse, thereby prolonging the life of the jack. An adjustable step is preferably provided, this step being slidable to difierent vertical positions along the lifter so as to secure a wide range of adgustment for the jack. Provision of" a guided lifter on the post is highly desirable when a step is provided, as such construction gives a balancing couple which eii'ectually prevents binding of the screw in the nut during operation.

The base preferably comprises a foot and an upstanding post. This post instead of being made vertical is preferably slightly inclined. An advantage of such construction is that when the load is supported on the step such load moves closer and closer to the center of the foot as the jack is raised and also comes more into line with the bottom of the post.

In the accompanyin drawings which illustrate the present pre erred embodiment of my invention and one modification thereof Figure 1 is a side elevation partly broken away.

Figure 2 is a front view ofthe jaclr shown in Figure 1.

Figure 3 is a horizontal section taken on the line TIL-TH of Figure 1.

Figure i is a side elevation of a slightly modified form of jack, and

Figure 5 is an elevation of a portion oi.

Figure l showing the manner oi'holding the lifting nut and the actuating mechanism in lace. P In the form of invention illustrated in Figures 1 to comprising a base indicated generally by the reference character 2 and a lifter indicated enerally by the reference character3. The use 2 comprises a foot 211 and an I up- 3 inclusive there is shown a jack tlii standing post 4. The foot and the post are preferably made integral and for large jacks the base may be a malleable casting, in which case it is desirable to provide strengthening arms 5 for distributing the load from the post over the entire foot. In lighter jacks it may be desirable to make this member from pressed sheet metal.

As will be seen from Figure 1 the post 4 is inclined slightly to the vertical and the advantages of this will be hereinafter set out.

The shape of the post in cross section is best seen in Figure 3. It will be noted that it is hollow as indicated at 6 and that a vertically extending slot 7 extends substantially the entire length of the post. Guide faces 8 are provided along the edge of the slot and rear guides 9 are also provided.

The lifter 3 is made U shaped in cross section as best seen in Figure 3 and is preferably formed from stamped sheet metal. Near the bottom of the lifter 3 there is provided a thickened slide portion 10 which cooperates with the guide faces 8. The lifter is further provided with inwardly turned flanges 11 which extend substantially the entire height of the lifter and cooperates with the guides 9. It will be seen that this arrangement,

especially when the lifter-is made to closely hugv the outer faces of the guide faces 9 as shown in Figure 3, forms a construction which substantially prevents wobbling between the base and the lifter at any position.

This of course means that the screw is re 'lieved greatly, if not entirely, of sidewise load.

The screw extends vertically in the opening 6 of the post 4 and is secured at its top to the lifter 3 as indicated at 12. An extension 13 is provided on the lifter at the bottom thereof adjacent the slide 10 and a holding bolt 14 passes through an opening in this extension 13 and through the slide 10'to'securely hold the bottom of the screw in place.

A thrust bearing 15 is provided at the top of the post 4 and a nut 16 rests on top of this hearing. The nut 16 is provided with a bevel gear portion 17 cooperating with a bevel pinion 18, mounted on a stub shaft 19. The stub shaft fits into the lower half of a bearing 20 formed in the top of the post 4 and is held in place by a bearing cap 21. The stub shaft is held against endwise movement by a collar 22 on the end of-the shaft adjacent the pinion and by a knurled or otherwise roughened enlargement on-the outer end thereof. This enlarged portion provides a very convenient means for initially setting up the jack to the right height before the actual lifting. A square hole is provided in the end of the stub shaft 19 to receive an operating shaft 24 which is preferably made removable. The shaft 24 may terminate in a crank and be of any length so that the jack may be operated from a distance if desired.

The bearing cap 21 is provided with a wing 25 having an opening therein to accommodate the upper end of the nut 16. The nut is provided with a shoulder portion 26 which fits into the wing 25 so as to form a suitable bearm lhe top of the lifter 3 is suitably formed to provide a load engaging face 27 but a step 28 is also provided to give the jack a wider range of usefulness. The step 28 comprises a U shaped body ortion 29 which fits snugly around the lifter, as shown in Figure 3, and is provided with fingers 3O lying behind the inwardly turned flanges 11. It is further provided with an edge 31 adapted to engage in one of a number of teeth 32 which are stamped up from the body of the lifter proper. When it is desired to move the lifter to various positions it is shifted to the dotted line position of Figure 1 and is slid up or down the lifter to engage a suitable tooth 32.

When the lifting force of the jack is exerted through the step 28 a force couple is set up by reason of the downward force of the load and the upward force of the screw. This is balanced by an equal and opposite force couple set up by resistance between the I flanges 11 which is materially closer to the top of the jack than can be secured by the guides 9 alone.

As previously pointed out,'the post 4 in this embodiment of the invention is not truly vertical. This arrangement has several ad vantages. The front and rear wheels of the ordinary automotive vehicle are of the same size. This means that if a tire is flat the axle lies below the axle at the other end of the car and therefore when such axle is lifted by the jack it passes through its normal position. During this movement it travels outwardly since it moves on the arc of the circle'whose center is the remote axle of the car. This movement is to a large extent compensated for by the inclined post and there is less tendency for the jack to tilt or shift its position. Anothenimportant advantage is that as the load is lifted the effective force transmitted to the foot comes materially closer to the center of the foot than it otherwise would. Also when the step 28 is in its upper position the hue of force of the load is materially closer to the guides of the lifter than otherwise would be.

Referring to Figures 4 and 5 there is shown a slightly modified form of jack. In these figures of the drawings similar parts have been given the same reference characters as were used in the description of the first embodiment of the invention but with a letter b suflixed thereto. In this form of the invention the lifter 3b is formed from a U shaped metal shield 40, but instead of this shield having teeth 326 formed therein such teeth are made in a separate member 41. This member is preferably a malleable casting having a portion 42 extending across the top of the lifter to engage the screw 43 and having a portion 44 extending into the interior of the post 46 to engage the bottom of the screw. The step 28?) is of a slightly different form and is provided with studs 45 working in slots 46 on either side of the member 41. In this form of the invention the step 286 may be disengaged from the teeth 32'!) and rotated around the studs 45 until it lies over the portion 4": as indicated by dotted lines. This raises the effective height of the jack for a direct lift.

Instead of the bearing for the stub shaft 19?) being formed directly in the top of the post 4?) there is provided a stamped metal bearing half 45 and a stamped upper bearing half 46. These two pieces'are assembled with the stub shaft 19?; and nut 16b and the parts are held in place by rivets 47 which pass through wings 4:8 in the bearing halves and wings 49 on the top of the post 4?).

I have illustrated a preferred form of my invention and one modification thereof, but it will be understood that the invention is not limited to these forms as it may be otherwise embodied in the scope of the following claims.

I claim 1. A jack comprising a base having an upstanding post with an open sided recess therein, a lifter lying outwardly of and embracing the post, the lifter extending across the open side of the recess, a screw secured to the lifter at the top and bottom thereof andlying in the recess, a nut mounted on top of the post, and means for relativelyrotating' the nut and the screw, the portions of the post adjacent the top of the recess forming a seat for the nut.

2. A jack comprising a base having an up tive rotation between the screw and the nut to raise the lifter on the post.

In testimony whereof I have hereunto set my hand.

CLARENCE J. RODMAN- standing post with an open sided recess therein, a screw lying in the recess and projecting from the upper end thereof, a bearing mounted on top of the post and surrounding the screw, a nut on the bearing, a lifter guided in the post and operatively connected to the screw, and means for rotating the nut.

3. A jack comprising a base having an upstanding post with an open sided recess therein, a lifter lying outwardly of and embracing

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