US2057870A - Jack - Google Patents

Description

Oct. 20, 1936. v J. A. ADELL V2,057,870

JACK

. lOriginal Filed Jan. 30, 1953 3 Sheets-Sheet 1 J. A. ADELL Oct. 20, 1936.

JACK

Original Filed Jan. 30, 193.3 3 Sheets-Sheet 42 Oct. 20,1936. J, A ADELL Y 2,057,870

JACK

Original Filed Jan. 30, 1933 5 Sheets-Sheet 3 Patented @et 20, 1936 @FFEQE JACK .lohn A. Adell, Orange, Mass., assignor of onehalf to Alvin L. Johnson, Worcester, Mass.

10 Claims.

This invention relates to a jack capable of general use but particularly adapted for automobile use.

The principal objects of the invention are to provide a jack having a single screw cooperating with means capable of extending the height of the jack up to approximately three times the length of the screw and the casing in which it is located, with improved means for lifting and supporting certain of the lifting members of the jack; to take the major lifting strain off the jack casing so that the same may be made of comparatively thin or sheet metal or other material and will serve to protect the interior of the jack from the entrance of dust and dirt; to provide means for protecting the working parts from any dirt or foreign matter; to provide a housing or casing which is light in weight yet which provides a strong and accurate guide for the lifting members eliminating expensive machining operations; to provide a plurality of cooperating or telescoping lifting devices or elements coacting with a single screw and having means, supported by one element, for holding another element in its expanded or extended position and yet capable of being automatically withdrawn to allow the upper one to be telescoped into the lower one by the simple operation of said screw; to provide a simplified jack of this type; to provide means whereby the working parts lare/reduced to a minimum and the lifting elements arranged so that they cannot be rotated and therefore cannot rotate accidentally to let the load down, and to avoid expensive devices for preventing rotation.

Further objects and advantages are within the scope of this invention such as relate to the arrangement, operation and function of the related portions of the structure, to various details of construction and to combination of parts, elements per se, and to economies of manufacture and numerous other features as will be apparent from a consideration of the specification and -drawings of a form of the invention, which may be preferred, in which:

Figure 1 is a side elevation of a jack casing constructed in accordance with this invention;

Figure 2 is a similar view showing the jack eX- panded or in extended position;

Figure 3 is a plan of the jack;

Figure 4 is a sectional view on the line 4-4 of Figure 3, on enlarged scale;

Figure 5 is a sectional view of the jack casing on the line 5-5 of Figure 1;

Figure 6 is a plan of the driven gear showing f the operating screw in section;

Figure '7 is a sectional view taken diametrically through the center, showing the parts in contracted position;

Figure 8 is a side elevation of an inside lifting member of the jack;

Figure 9 is a horizontal sectional view on the line 9-9 of Figure 8;

Figure 10 is a plan of another lifting member;

Figure 1l is an elevation of the same;

Figure 12 is a longitudinal sectional view thereof of a supporting member;

Figure 13 is a sectional view on the line I3-I3 of Figure '7;

Figure 14 is a View similar to Figure 7 showing an inside lifting member in raised or extended position;

' vFigure 15 is a similar view of the lower part of the jack showing an outside lifting member also in raised or extended position;

Figure 16 is an enlarged isometric View of the L upper portion of one of the lifting elements;

Figure 17 is an enlarged view of the lower portion of one of the lifting elements and the threaded portion thereof;

Figure 18 is an enlarged view of the lower end portion of another of the lifting elements showing the nut arrangement thereof.

This jack is particularly designed for use with automobiles having oversized tires but it is to be understood that its use is not so limited, and it is shown as having a casing I9 prefer-ably formed of sheet metal riveted or otherwise secured to a base member II also preferably formed of sheet material. This casing, as will be seen later, does not carry any substantial portion of the vertical load and consequently can be made of comparatively thin sheet metal, thus reducing the cost and weight of the jack materially. The casing 1s shown as formed of a single piece of sheet metal shaped to form a complete enclosure, the meeting edges or portions thereof being provided with flanges I2 riveted or otherwise fixedly secured together, but it is be understood that the casing may be made in sections secured together without departing from the spirit and scope of the invention. At one side near the bottom the casing is formed with a cylindrical bearing to receive a shaft I3 adapted to be rotated by means of a handle, wrench or other means for operating the jack.

On the base I I rests a thin plate member lli having a circular flanged portion at the center. Resting on the base and projecting up through the central perforation adjacent the flanged portion is a cup like race I6 for a circular series of beartional design may be employed in lieu of the particular type of plate gear illustrated. The gear or rotary member i8 is a stout plate formed of metal of comparatively great thickness and it supports a screw 22 which is centrally riveted, swaged, or otherwise secured to it through the plate I8.

' These two members I8 and 22 therefore are con-V nected with each other and, as will be seen, these parts cooperating with pinion 2I constitute the rotary elements in the jack. The threads of the screw 22 do not extend clear to the bottom thereof but are entirely omitted throughout an area at the bottom of the screw which constitutes a neck 23 which is preferably cylindrical Yand vfree from screw threads. The power or means for operating the jack, it will be observed, is introduced through-the shaft I3, the pinion 2I and gear I8 and the friction is reduced by supporting the gear I8 and screw 22 on the bearing balls in the manner shown.

Referring especially to Figure A"I, it will be seen that there are two lifting members 24 and 25. These are preferably constructed as non-circular hollow members slidably tting one within the other, as shown. These members do not rotate individually or relatively, so it is convenient to make them square or non-circular in cross section with rounded corners facilitating the manufacture of these members of sheet material. The inner Yor rst lifting member is provided with a head 26, preferably held by projections 26a extending into the member 25. It is preferably made flat on top except that the upper surface may be roughened because it constitutes the surface which engages the axle of the vehicle or other article to be lifted. However, Vit is not as necessary to roughen it as it would be if it were capable of rotating because there is no tendency for it to turn on its axis away from the member which it supports. Y

As particularly illustrated in Figure 17, the lower portion of the inner tube or lifting element 24 is provided with a threaded portion or nut 21, as illustrated, this nut being a separate member and by means of tongue and groove connection snuglyvts the extremity of the tube 24, the parts being welded or otherwise secured together as at 21. The nut 21 is provided with threads which are adapted to mesh with the threads of the screw 22. The nut 21 is formed with a substantially rectangular portion 29 so that the corners or projections 29 extend outwardly beyond the rounded corners of the lifting element or tube 24 and serve as stop means for limiting the upward movement of the lifting element 24 with respect to the outer lifting element 25.

Any rotation of the gear I8 in the proper direction, wheny the parts are in the position shown in Figure 7, will raise the nut 21 and consequently the lifting member 24. The limiting position of this lifting` member is shown in Figure 14.

As particularly illustrated in Figure 18, the outer lifting member or tube 25 is also provided with a threaded portion or nut 28, in the embodiment illustrated the nut being a separate member fixed to the lower end of the tube which under certain conditionsy of the operation of the jack is meshed with the threads of the Vscrew 22 as will be hereinafter explained. The nut 28 is welded or otherwise secured to the lifting member 25 to form a Vthreads until caused to in to limit the uppermost extended movement of the Y lifting member 24 as will be hereinafter explained in detail. In the contracted position shown in Figure 7 the nut 28 supports the'nut 21 and prevents the latter nut from moving below the bottom screw thread. Normally the nut 28 rests on the plate or gear I8 and is of such a width that it is all received within the unthreaded neck 23 of the screw 22 and does not engage the screw the manner that will be explained hereinafter. V

The member 25 is provided in one side with an opening 38 Vwhich preferably `extends throughout most of its length. In that opening is Va relatively movable element 3I of UV-shaped cross section` which constitutes a supporting member fortheV inner lifting member 24 when the latteriis ex-V tended to or beyond the'position shown in Figure 14. The bottom 3I is provided on the outer side with a toe or ange 32 and riveted tothe member 3I on the inside or bight of the U-shape is a bow shaped or convex resilient member or spring 33 which is free from the supporting member 3I at thetop and has sliding engagement with it. The toeV 32 engages an inclined cam surface 35 which in the embodiment illustrated is a separate piece of of the supporting member Y metal 36 that is welded or otherwise securedV to Y' an inside wall of the casing. The top of the supportingmember 3I also engages a similar camY surface 31 thereon.

This supporting member can move therefore' in the opening 30, which it substantially ts and it is always in contact Vwith and supported by the member 25 and/or its nut or threaded por-Y tion 28. Normally this spring 33 will engage the outer wall of the inner lifting member 24 in the position shown in Figure '1 and against the screwV 22 when the parts are in the position shown in Figure 14. The casing I 0 is provided with an internal vertical groove 38 for accommodating the supportingV member 3I.\ The outer lifting member 25 has inwardly extending projections 39 as particularly illustrated in Figures 11 and 16'at some or all of its corners for engaging the sharp corners 29 of the nut 21. The bottom nut 28 has two opposite wings 40 extending into two inside grooves 4I in the casing. The ends of these grooves constitute stops to limit the upward movement of member 25.

During the raising or extension of the lifting member 24 nearly to the position shown in Fig-v ure 14 the nut 28 is inactive and the lifting Vmember 25 is not raised. However, the bottom of the slot or opening 3U serves as `a support for the supporting member 3| at all times vand the nut 28 has a shoulder for that purpose. Just as the parts move to the position shown in Figure 14, on the upward stroke, the corners 29 engage the projections 39 and start to lift the lifting member 25. The result of that, of course, is to lift the nut 28 until it engages the threads 22. Immediately after the corners 29 of the nut 28 engage projections 39 indented in the corners of the lifting member 25, the latter member begins its upward travel at which time the nut V28 comes the screw 22. At this point in the operation, the

"toe 32 engaging cam surface 35 and the upper edge of the supporting member 3| engaging cam surface 31 causes the supporting member 3| to move inwardly beneath the outer lifting member 24 serving as a substantial and rigid support for the member 24.

The continued rotation of the gear I8 in the same direction will raise the nut 28, the supporting member 3|, the lifting member 24 and, of course, the lifting member 25 without further changing of the relative positions of the parts 24 and 25. Thus finally the lifting elements may be moved to the position shown in Figures 2 and when the stops 46 prevent further extension or removal of the outer lifting member.

On the downward motion or retraction of the lifting elements the effects take place in the opposite sequence. The outer lifting member 25, through its nut 28, is brought down first from the position shown in Figure 15 to that shown in Figure 14. The screw, rotating continuously in the same direction, causes the threads of the nut 21 to again engage the threads of the screw 22 before the nut 28 entirely leaves the same. v

Consequently there is no discontinuity of action while one nut leaves the thread and the other enters it. As the member 25 moves downwardly and approaches its lowermost position, cams and 31 cooperating with member 3| permits the latter to move outwardly from beneath the member 24, the member 3| being urged in this direction by means of the spring 33. Consequently the inner lifting member 24 is free to descend the moment the outer lifting member has substantially reached the bottom of its travel. Then the outside surface of the member 24 as it is retracted engages the spring 33 and holds the member 3| in its outermost position. Finally the parts are all retracted or come down to the position shown in Figure '1 if the gear is operated long enough to bring the parts to that position. It will be seen that the motion from full closed to full open position and vice versa is continuous without any interruption.

'It will be noticed that the casing I0 is not called upon to bear any substantial part of the weight of the object to be lifted or elevated by the jack and consequently it can be made of comparatively thin or sheet metal. The member 3| is a strong and rigid member through which substantially the entire weight of the load is supported after the nut 21 leaves the screw 22.

It will be observed also that the screw 22 is entirely located within the casing and within the lifting member which construction substantially eliminates the ingress of dust and dirt to the operating mechanism.

1t will be seen further that a jack is provided wherein several lifting elements may be successively extended and retracted through the operation of a single screw, thus very greatly simplifying the jack itself and reducing the cost of manufacture. Because the lifting members are not rotatable, either individually or relatively, there is no danger that the turning of the piate 25, which supports the work, will cause it 'to creep, from beneath the load.

The operation of the jack of my invention is as follows: Assuming that the parts of the jack are in retracted position as illustrated in Figures l and '1, to tool or operating handle is first inserted in an opening contained in shaft I3, and the same rotated to cause rotation of gear 2|,

which meshing with plate gear |8 causes rotation of the vertical screw 22. As the nut 21, xed to the lifting member 24 .is enmeshed with the threads of screw 22, the member 24 will be elevated during proper rotation of gears |8 and 2|. When the member 24 has been extended substantially to the position indicated in Figure 14, or until the corners of nut 21 engage with the indented stops 39 in the corners of lifting member 25, at which time continued rotation of the operating gears will initiate upward movement of the lifting member 25, bringing the threads of nut 28 fixed to the lower part of lifting member 25 into enmeshment with the threads on the vertical screw 22. Both lifting members 24 and 25 are now moving'upwardly in relatively xed relation, and as member 3| is in engagement or in Contact with the walls of opening 3|) in lifting member 25, it is also caused to move upwardly at which time cam surfaces 35 and 31 cause an inward movement of supporting member 3| toward the lifting screw, bringing member 3| beneath the lifting member 24 to form a rigid and strong support for the member 24 after the nut 21 has been moved out of mesh with the threads of the screw 22. Further rotation of the screw 22 will extend the lifting elements 24 and 25 to substantially the position illustrated in Figure 15 until the stops 4i! on nut 28 engage the upper ends of grooves 4| formed in the casing IB of the jack, preventing further extension or disengagement of the lifting members.

Rotation of the gears 2| and I8 and the screw 22 in the opposite direction will retract lifting members 24 and 25 until the threads of nut 21 again mesh with threads of screw 22, and for a short period of rotation of screw 22 both nuts 21 and 28 are in enmeshment with the threads on screw 22. At approximately this time, the member 3| under the influence of spring 33 has reached a position with respect to the gears 35 and 31 which permit it to be urged to its outermost position away from its position beneath the lifting element 24, so as to permit the lifting element 24 to be further retracted. Nut 28 eventually reaches its lowermost position as shown in Figure 14, wherein the threads of the nut are out of mesh with the threads of screw 22 which defines the lowermost position of lifting member 25. Further rotation of screw 22 will therefore retract the lifting member 24 substantially to its initial or completely retracted position.

In the practical application of my invention, I have found it very desirable to so construct the jack that the friction coefficient between the outer lifting element and its guide or the casing will be greater than the coefficient of friction between the contacting surfaces of the inner and outer lifting elements. This may be accomplished by having a more snug sliding fit between the outer lifting element and the casing than the t between the inner and outer lifting elements. By means of such an arrangement, should the jack be used in a position that a lateral strain may be imposed upon the lifting elements and the associated parts, the friction between the outer lifting element and its casing will tend to prevent the outer lifting member from being carried upwardly during the upward extension of the inner member prior to the engagement of the corners of the nut 21 with the indented projections or stops 39 in the outer element, making a satisfactory and smoothly operating mechamsm.

It is apparent that, within the scope of the invention modifications and different arrangements may be made other than is herein disclosed, and the present disclosure is illustrative merely, the invention comprehending all variations thereof.

I claim: 1. A lifting jack comprising a casing having an enlarged lower portion and a tubularl upper portion; a plurality of extensible lifting elements telescopically arranged within said casing, Ysaid vments in its extended position,

2. A lifting jack comprising a casing formed of sheet metal having an enlarged lower portion Vand a tubular upper portion; a plurality of extensible non-circular lifting elements telescopically arranged within said casing, said lifting elements having intern-ally threaded portions; a screw adapted for cooperation with the :threaded portions for successively extending and retracting said lifting elements; a plate gear positioned within the enlarged portion 'of said casing and operatively connected to s-aid screw; a laterally extending cylindrical bearing formed integrally with said casing; a driving gear for said pl-ate gear journalled for rotation i'n said cylindrical bearing; a member positioned Within said casing at all times and arranged substantially parallel with said lifting elements; and means whereby said elongated member is automatically moved radially to support one of said lifting elements in its extended position.

3. A lifting jack comprising a casing formed of sheet metal; ar base plate therefor, said casing having an enlarged lower portion and aV tubular upper portion; a plurality of non-circular lifting elements telescopically positioned within said casing in said tubular guide portion, said lifting elements being provided at their lower portions with internal threads; a screw for operating said lifting elements, one of said lifting elements having an elongated opening in a wall thereof; a supporting member arranged in said opening adjacent a wall of said casing; spring means normally urging said supporting member to one position; and means whereby said supporting member is moved transversely for supporting another of said lifting elements.

4. A lifting jack comprising a casing formed of sheet metal; said casing having an enlarged lower portion and a tubular upper portion; a plurality of noni-circular lifting elements telescopically positioned within said casing in said tubular guide portion, said lifting elements being provided at their lower portions with internal threads; a screw for successively extending and retracting said lifting elements; means on said lifting elements for limiting the extension of said elements with respect to each other; means cooperating with one of said lifting elements and the casing for limiting the extended movement of said lifting elements with respect to said casing, one of said lifting elementsfhavingl an elongated opening in a wall thereof; a supporting memberY arranged in said opening ad- Ymembers and a pair of nuts jacent a wall of said casing; means normally' urging said supporting member to one position; and means whereby-said Ysupporting memberis moved transversely for supporting anothery of said lifting elements. Y

5. A lifting jack comprising a casing formed of sheet metal; abase plate therefor, said casing having 4an enlarged lower portion and a tubular upper portion; a plurality of non-circular lifting elements telescopically positioned within said casing in said tubular guide portion, said lifting elements being provided at their lower portions with threaded nuts; a screw cooperating With said nuts for extending and retracting said lifting elements; stop means carried by said lifting elements for ylimiting the extended movement of said elements with respect to eachother and said casing, one of said lifting elements having an opening in a wall thereof; a supporting member of substantially U-shape cross section arranged ins-aid opening adjacent a wall of said casing; spring means normally urging said supporting member to one position; and cam means for transversely moving said member for supporting anotherY of said lifting elements.

6. In a lifting jack comprising in combination,V

a easing; a rotary screw and twoI telescoping lift# ing members in said casing, each having a nutV at the bottom for operative engagement with the screw; a supporting membernormally supported by the one lifting member and extending substantially from the bottom to the top of the casing forrdirectly supporting the other telescop-V ing member therefrom upon extension of said second mentioned telescoping lifting member.

7. InV a lifting jack comprising in combination, a casing; a rotatable screw; a pair of telescoping in said casing, each nut being xed to the lower portion of each of said telescoping members and both adapted for cooperative engagement with the screw; a vertical supporting member normally earried by one of said members, the upper end of which supporting memberis adapted to move under the bottom of the other telescoping member, and means urging said supporting member inwardly when said other telescoping member moves substantially to an extended telescoping member. Y

8. A lifting jack comprising in combination a single rotatable operating screw; a pair of telescoping members and a pair of nuts,V eachrone fixed to the lower portion of one of said telesco-ping members; a supporting element normally extending substantially parallel with said tele- 9. A lifting jack in combination, a casing; -al

single operating screw in the rotating the screw; a pair of scoping lifting members; a nut carried at the lower end of each lifting member adapted for operative engagement with said screw; an element adapted to-reston one of said nuts and extending upwardly in the casing; and a stationary cam surface engageable with said memberl to casing; means for nonrotatable teleposition to support that project its upper end laterally into Contact with a lower portion of the inner teleseoping member for supporting the same therefrom, as the outermost telescoping member rises.

10. A lifting jack, in combination, a easing; a single operating screw in the casing; means for rotating the screw; and a pair of non-rotatable telescoping lifting members, each having a nut adapted to operatively engage said screw; of an element adapted to resi'l on one of said members but separable therefrom and extending vertically in the casing; cam means engageable With said element for causing transverse movement thereof to project its upper end to a position to support the other of said telescoping members; and yielding means for urging said element out of supporting position with the telescoping member.

JOHN A. ADELL.

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