US1527542A - Lifting device - Google Patents

Description

Feb, 24, 1925.

' C. T. EARHART LIFTNG DEVICE Filed oct'. 22, 1921 2 Sheets-Sheet 1 UWRLES 25mg/mg JNYENTOR,

Patented Feb. 24, 1925.

1,527,542 PATENT OFFICE.

CHARLES T. Eliminar, or rrr'.iusisunefni,` rENNsYnvANIA.

' nrr'rnve DEVICE.

Application fueaoctber 22, 1921. seriai Nousoeyiz.

To cZZfLoLmfz't may concern.' 'Y i Be' it known that I, CHARLES T. EARHART, a! citizen of the United States of America, residing at `Pittsburgh, in t-he county of Allegheny and `State of Pennsylvania, have invented certain `new and useful Improvements in Lifting Devices, of which the following is a specification.

The present inventionrelates to lifting devices, and is more particularly useful for the' purpose of raising Aautomobiles to an elevated position oif the ground, for a varietyof purposes suchas relieving the Itires of their load, when the automobile is not in use, or `for repairing the under parts i of same. The invention possesses Amany advantages of which the following are illusz trative thereof. i f y Two specially*constructed --liftingjacks `which `are connected to `each otheract in unison to "raise the@ load, evenly and simultaneously, there being no side tipping, `nor end tipping ofthe automobile during the liftingoperation due to the means adopted for operating the device. f

Anotl'ier feature of the device is the specially constructed operating mechanism used to operate the lifting jacks, which can beat-tached readily to either jack, so that e the.. automobile can be raised from the front or the rear depending'on the situation which confronts theuser in his own particular `garage.V A, feature of the operating mechanism forming part of the device is that h v merely turning a small spring held and gravity actuated lever, as will be more particularly described hereinafter, kthe same lever which is operated with an up and downmotion to raise the jacks, can also be used to lower the same, and witha similar up and down motion. The operating mechanism 'has an additional feature that the lever which is used to actuate same operates the mechanism within both on `the up stroke, and on theV down stroke of the operating hand lever, asfwill be described.

By means of 'f the specially Vdesigned toothed racks, a pair of whichare used in hyinsuring an even lifting operation.

All the advantages f above mentioned will i(not shown) be more fully brought out as the description proceeds, as well as others and it is not desired to limit 'myself to the. exact structure ldescribed herein and shown inthe drawings accompanying this specilication, but departures may be made therefrom, all within the scope of the claims.

In the` accompanying drawings forming part of this specification I have shown one `complete `example of the `physical embodilment of my invention constructed according` tothehest mode Ihave so fai-devised for the practical application of the principles of my invention. i

In thedrawings accompanying this speci- 'iic-ation, and forming a. part hereof,

invention, showing the'itoothed racks in eX tended or their highest positions.

Figure 2, is a vcentra-l.transverse vertical section on line 2 2 through the 'operating mechanism, of Figure thereof. f

Figure 3 is a horizontal section on line 3 3 of Figure 2l f Figure 4 is a vertical section of the lifting jacks used .taken on the center line of Figureg..

Figure 5`is a topplan view,fpa`rtly in section, lof one of the lifting jacks with the operating mechanism attached thereto.

Inl the drawings, the numerals 1 and 2 indicate a pair of lifting jacks of special construction, each having toothed racks such as 7, 8, 9, 10, as shownclearly in `lSigure 1, joined at their upper ends by cross .bars 3,4. The two jacks 1 and 2 areyconnected `by thehorizontal` shaftsf, 6, each of the latter being connectedsuitably to the inte rior parts of each jack, thus enabling the toothed racks of each jack to be lifted si- `multaneously by the operating mechanism 11, as will bemore fully described.

\ Thelifting jacks lland 2 are `substantially similar, exceptthat `they are made opposite hand, and their cross bars are slightly diiferent in design as illustrated in Figure 1,-of the drawings, the cross-bar l having a depressed portion 12 adapted to engage under the Diiferential gear box of an automobile conveniently, while the cross bar 3 is straight or horizontal and more properly adapted to engage under the front aXle of an automobile as is readily' understood. In View of the similarity of the two jacks the descrip- Figure 1 is a perspective vieuT of the whole 5, looking to the right tion of one Will 'suffice for both. The lifting jack 2 comprises the following parts and the views .of Figures 4 and 5 are of this particular jack, as will be at once V'seen upon inspection of the drawings. The numeral 13 indicates an enclosed casing or box having a pair of outwardly turned feet, 14, 15 adapted to slidably receive the before mentionedtoothed racks 7 'and 8. At tention is directed to the fact that thesimilar feet 14 and 15 are curved from 16 to 17 in each case to the arc of a circular curve, while the toothed racks 7 and 8 are of a special curved and tangential design adapted to constantly engage against the pinions 18, and 18, while their outward extensions 19, 2O engage under the inner Walls 21, 22 of the feet 14, 15 respectively of the casing 13. In this connection it is seen that the racks 7 and 8 are curved from pointsat approximately 23 and 24, whileI there are tangential portions Ifrom points 23, 23 to their other ends at points 25, 25 in each. Rollers 26, 26, are yused lin the ends of the racks as shown to `facilitate movement of the racks along the under walls 21, 22 of the feet 14, 15 respectively, but it is found in practice that they are scarcely necessary, they outward extensions 19 and 20 being found sufficient. The small rollers 27, 27 mounted in the walls of the casing 13 also form `guides for the racks 7, 8 as they are operated, but their guidi-ng function is found to be surpassed in importance in practice by their stop function, as when the racks reach their highest points as indicated by the dotted positions of the racks 28, 28, it is eJident from Figure. 4 that the outward extensions 19, 20 engage under said rollers 27, 27 and prevent the racks 7, 8 from being ejected from the casing 13, as illustrated at 29, 29 in said Figure 4. The upper ends of the racks 7, 8 are connected by the cross-bar 4, pivotal connections being used at points 30, 30 as shown. The pinions 18, 18, are rotatably mounted in the side walls 32, 33, of the casing 13, and the ends 34, 35 are connected to the shafts 5, 6 extending between the lifting jacks 1 and 2. On the opposite ends of the shafts 5, 6, as is readily appreciated, are duplicate pinions to 18, 18, and in the lifting jack 1, so that when the 'pinions 18, 18, and racks 7, and 8 are operated the duplicate racks 9, 10 also rise simultaneously. On the outer ends ofthe pinions 18, 18 are bevel gears 36, 37 which mesh with complementary bevel gears 38,39 of the operating mechanism 11, from which they receive actuation as will be described. It is evident that when the gears 36, -37 are actuated that the racks 7, 8 and thecrossbar 4 will rise or fall according to the direction of rotation of said gears 36,377; and further that as the two lifting jacks l and 2 are geared together and similarly geared,

both cross-bars 3, and 4 to rise simultane- "ously -and equally, thus raising the automobile with both the front and rear ends thereof smoothly and regularly.

.lnorder to avoidside tipping of the automobile while same is 'being raised it is evident that the ends 40, 41 of each cross-bar 3 and n4 nu'st rise evenly in order to `accomplish this purpose. is accomplished by means kof my speciallyndesigned and constructed toothed racks before/described, to wit 7 and 8, -therjupper ends of which rise ina vertical rectilinear line, while the lower ends of said racks follow a circular arcuate motion adapted to travel along the inner walls21, 22 ofthe casing 13. This particular design of toothed rack is aspecial feature -of my device'as can be seen from` an Vinspection 'of the Figure 4 of the drawing. The ends 42, 42 of the racks travel in a vertical `straightline fromtheir lowest positions -at 43, 43 to' their highest positions 44, 44; while the Y*lower Voutward extensions 19, 2O of said racks 7, 8 travel along the ci'rci'ilararcuate paths indicated by the inner walls 21, 22 Vof the casin y 13, from the lowest . positions 45, 45 to the ighest positions 46, 46 of said racks. It is noted in passing that the weight of the automobile or load on the cross-bars 3, 4 tends to hold the teeth 74, 74 of the racks 7, 8 against the pinions 18, 18, while 'the rollers 27,27 engage against the inner walls 21, 22, of the casing and give 2rigidity to the racks and cross-bar considered asa trussed structure, when -same are being elevated or depressed, so as to prevent the side-tipping of the automobile above mentioned` Special attention is directed to the special requirements of the shape of the racks 7 and 8, to wit, their upper ends 42, 42 must lrise in a straight line vertically, their teeth must always engage against the teeth of the vpinions 18, 18., while their lower outward extensions must travel along a circular' arcuate line, said extensions -having also a proper projection on each `adapted to engage against the rollers A27, 27 'to lprevent the ejection yof the racks from the casing 13.

kAs a further requirement of the racks 7 and 8, it is seen that-same are made or constructed so that Vthey are rigid lthroughout their length, sol that whenthey are in extended positions as at 128, 28 of Figure 4, they remain linflexible under load, as is readily seen to be necessary to prevent sidetippingof the automobile when same is being raised or lowered.

Attention is directed to the following points with reference to the use of the specially designedracks used in the present invention. Byusing the irregular transition curve for said racks the jack can be made low enough to accommodate the very lowest type of automobile, as the height ot extended jack in proportion to its retracted or closed height is much greater than the usual type of jacks in common use. To illustrate the point in hand, for an ordinary jack height of eleven inches when the jack is closed, it is usual to get say an extended height of jack of seventeen inches, or a proportionate rise or extension ott six inches to a. closed height ot eleven inches. In the case of the present invention, the jack in closed position usually measures six inches with a rise to extended position of thirteen and three-quarters inches, or a. seven and threequarter inch extension to a closed height ot' six inches. From which it is seen that the proportionate extension per height oi' jack is about two and three-tenths times greater with the present invention, than in the case of the ordinary jack above selected. Also the fact that the height of ack when closed is only six inches, which is due primarily to the use of the specially shaped racks permitting such a low construction, is one of its most important features froma practical standpoint7 so that the jack can be inserted under low types of automobiles even when the tires are deflated.

The operating mechanism forming part of the present lifting device comprises the following parts. 47 is a preferably cast metal shell as seen in Figure 2, in which is rotatably mounted a ratchet 48, the outer ends of the Ashaft 49 on which the ratchet is mounted having each a bevel gear 38, 39 before mentioned in this specification as n complementary `engagement with the bevel gears 36, 37 of 'the lifting jacks l and 2. Mounted also in the shell 47 at 50 is the short hand level' socket 5l, which is pivotally mounted at said point 50. On the part 51 are pivot-ally mounted the two pawls. 52, 53, at points 54, 55 respectively. Each pawl is adapted to engage the teeth of the` ratchet 48, and each has a downwardly extending arm 56, 57 as shown. It is evident that as the hand lever 58 which is inserted in part 5l is operated up and down, that the pawls 52, 53 operate the ratchet 48 and also the gears 38, 39, the direction ot motion depending on whether the downwardly extending arms 56, 57 are held in an upper position as shown in full lines in Figure 2, by means of the gravity actuated and spring held lever 59 in position as shown in said Figure 2, in full lines; or whether the downwardly extending arms 56, and 57 are allowed to take a lower position, in which case the gravity lever 59 takes the position 60 shown dotted, thus freeing the ends 61, 62 of thepawls 52, 53 respectively. The gravity lever 59 mounted in the shell 47 of the operating mechanism is pivoted on a fulcrum point 68, and the axis 69 of said gravity lever extends through the casing 13, and has on its extremity the returned spring 7 (l, which bears yieldingly against the exterior of the shell` 47 as shown in Figure 3. Vrlhe axis of the shaft 69 on which gravity lever 59 is mounted carries a c-otter pin 7l extending therefrom as shown in Figure 3, the end of which engages under the body of the gravity lever 59, and when the spring is operated from the exterior of the shell 47, it is evident that the said gravity lever will be raised or lowered, and moreover the spring 70 holds the gravity lever 59 in any desired position. In the bottom 72 of the shell 47 is an adjusting screw 7 3 which controls the gravity lever 59, so that the downward extensions 6l, 62 of the pawls 52, 53 respectively may be properly adjusted, and the upper' endsv of' the pawls su'fliciently elevated to mount over the ratchet teeth when the ratchet 48 is operated in a clockwise direction, or to the right as seen in Figure 2. To further illustrate the action ot the parts of the operating mechanism assume that the ends 62, 6l of the pawls 53, 52, respectively are in the higher position as shown in full lines in Figure 2, it is seen that that pawl 52 just passes over the top of tooth 63 of ratchet 48 as the lever 58 is raised but will engage tooth 64 as the ratchet is? revolved in a clockwise direction by the load on the cross-bar 4 actuating the said ratchet. The load on said cross-bar 4 will have such an etl'ect as is readily shown vfrom an inspection ot Figures 4, 5 and 2 and it is believed needs no 'further demonstration. lllhile pawl 52 is in the position just described it is seen that pawl 53 is in engagement with tooth G5 preventing the sudden unwinding of' the ratchet 48. As soon as the lever 58 is further raised, the pawl 53 is disengaged from the tooth 65, by the action of the gravity lever 59 which is heavier on the end 6G than on the end 67, and is fulcrumed in the casing or shell walls at 68, but it is seen said pawl 53 is not treed before the tooth 64 becomes enga-ged with pawl 52, as otherwise the ratchet under load would rapidly revolve in a. clockwise direction, or to the right as seen in Figure 2. New as the lever 58 is lowered from` its highest position, and is, ot course tulcruined at point 50 before descril'ied` it is seen that the pawl 52 is slowly withdrawn from ratchet tooth 64 while the ratchet 48 slowly revolves ,in a clockwise direction by means of its own mot-ion (received from the load on the jack beto-re mentioned), being ten'iporarily held from speedy clockwise revolution by thepaivl as it slowly recedes to the right, until the pawl 53 (which has in the mean- 'time mounted over the edge of the tooth 65) comes into complete engagement with Ll (i the tooth 63 which has been also traveling to the right or in a clockwise direction. From which it is seen that the operation of the lever 58 up and down, will when the load is on the top of the jack cross bar 4 tending to aetuate the ratchet L18 in a clockwise direction. lower the cross-bar 4: and it-s load.

The above assumes that the gravity lever 59 is in its full position as shown in Figure 2, so as to hold the ends 6l G2 in their higher positions, thereby enabling the pawls to mount the teeth of the ratchet 4-8 alternately as the ratchet revolves in a clockwise direction. For the purpose of understanding the action of the pawls and ratchet when the gravity lever 59 is in the dotted position of Figure 2, it is evident that the ends Gl, and 62 of the pawls 52, 53 respectively, will as soon as freed from the gravity lever end G7, fallc as low possible, in which ease as soon as the lever 58 is operated about fulcrum 50, the pawls will at once act as ordinary pawls, each engaging against a tooth of the ratchet in turn advancing, and holding the same until the companion pawl engages a new tooth, and thus the ratchet L8 is revolved in the meantime iu an anticlocltwise direction or to the leftl as seen in Figure Q. t is seen that when the ratchet is advanced in an anti-clockwise direc-tion, that ou the 11p-stroke of lever 58 that each of the pawls 52, 53 in turn advance the ratchet 4S. The fact that both pawls advance the ratchet indiviaually is seen to be an advantage, in the additional facility obtained in revolving and advancing the ratchet quickly. This is readily seen from au inspection of the drawings and it is believed no further description of the operation of the device on this point is necessary. Then such action of the ratchet as that liust described takes place it is at once seen that the lifting jack is extended and the crossbar 4 rises with its loa-d to its highest position. It is also noted that the load may be readily held at any intermediate position desired without any special locking device other than the ratchet and associated parts, since both pawls when their lower extensions are freed from the gravity lever, will seek a quiescent position in the teeth of the ratchet, in which last position they will remain and resist further clockwise revolution ot the ratchet 48, and consequently further descentl of the load on the jacks, unless the hand lever 58 is further operated.

As the ope-rating mechanism actuates gears 36, 37 of the jack Q, it is seen from what has been heretofore stated that the jack l operates in consonance with the jack "2. by means of the longitudinal shafts 5, 6, thus raising both cross-bars 3, 4f simultaneously, evenly and equally, both with reference to their transverse motions and their` longitudinal motions, insuring an even raising of the automobile or other load to which the lifting device is applied.

Attention is also directed to the fact that as jack l is provided with bevel gears which corresponds to gears 36, 37 that the operating mechanism 1l can be attached to either end of the lifting device, which in some garage conditions is an advantage.

I claim:

l. In a lifting device, a movable member, rigid throughout its length, and means to actuate one end of said member with an arcuate motion, while the opposite end thereof moves rectilinearly.

2. ln a lifting device, a movable member rigid throughout its length, adapted for continuous contact with a predetermined fixed point, and means for actuating one end of said member in a rectilinear direction, while its opposite end moves in an arcuate direction.

3. ln a lifting device, a pair ofracks inflexible throughout their length, in the same vertical plane and mounted in a guiding support, and means for raising said racks with their upper ends moving in a rectilinear direction while their opposite ends move with an arcuate motion during the entire lifting operation.

4. ln a lifting device, a pair of racks inflexible throughout their length and in the same vertical plane, means for raising said racks with their upper ends a fixed distance apart, and in a rectilinear vertical direction while their 'opposite ends move with an arcuate motion, throughout said movement.

In a lifting device, a pair of diverging shaped racks rigid throughout their length, and in the same vertical plane, a cross-bar connecting the upper ends of said racks and adapted to hold said ends a fixed distance apart, and elevating means adapted to simultaneously raise said racks in a vertical rectilinear line throughout the elevating` operation.

G. In a lifting device, a plurality of littliaclzs, each having a pair of racks in- 'liexible throughout their length, adapted to be raised to an elevated position with their upper ends a fixed distance apart, and in a vertical rectilinear line while their opposite ends move with an arcuate motion, and means for simultaneously lifting all the racks at the same speed of travel.

T. In a lifting device, a rack rigid throughout its length, having an upper portion formed to a transition curve, a tangential portion merging into said curved portion, and having an outwardly projectine` end adjacent to said tangential portion of the rack.

8. ln' a lifting device. a rack rigid throughout its length, having an upper portion formed to a. transition curve, a tanllt) Cil

'gential portion merging into said curved portion, and an outward extension on the rack adjacent to the tangential portion, and means to prevent said rack from tipping over when same is in an extended position.

9. In a lifting device, an enclosing casing having a pair of opposed feet, a -air of racks rigid throughout their lengt each having an upper transition curved portion merging into a tangential portion, and an outward extension provided with a rolling means adapted to engage the inner wall of the enclosing casing, a pair of rollers mounted in the casing walls each forming a guide for one of the racksa pair of pinions mounted in the casing engaging the complementary teeth of the racks, and a pair of bevel gears on the pinion shafts for the purpose of actuating the pinions and raising the racks to an extended osition.

10. In a lifting device, a plurality of lifting jacks, each provided with a casing having a pair of opposed feet, and a pair of racks inflexible throughout their length, and in the same vertical plane, a pair of revoluble shafts mounted in the lifting jack casings each having a pair of pinions adapted to engage one of the racks, and means for operating the pinions simultaneously for the purpose of elevating the racks to extended positions.

11. In a lifting device, an enclosing casing, having a pair of racks inflexible throughout their length mounted therein, adapted to be raised with their upper ends in a vertical rectilinear direction, and their lower ends in an arcuate direction, a pair of pinions engaging said racks; an operating mechanism comprising an enclosing shell, a ratchet mounted in the latter, connecting means between the said ratchet and the pinions of the rigid racks, a socket member pivotally mounted in the shell of the operating mechanism, a pair of pawls pivotally mounted in the socket member on opposite sides of its pivotal point, and each having a downwardly extending arm thereon, a gravity actuated lever mounted in the operating mechanism shell, and locking means for securing ,the gravity lever in positions for controlling the direction of rotation of the aforesaid ratchet.

12. In a lifting device, an operating mechanism having al ratchet and a support-- ing shell therefor, a 4socket member pivotally mounted in said shell, a pair of pawls pivotally mounted in the socket member each adapted to advance the ratchet in the same direction, and each having a downwardly extending arm thereon, and gravity means for controlling the act-ion of said awls so that the ratchet may be operated in either a clockwise or anti-clockwise direction, when the hand lever socket member is recipnocated,

13. In an operating mechanism for a lifting device, a ratchet and a supporting shell therefor, a socket member pivotally mounted in said shell, a pair of pawls each adapted to advance the ratchet and mounted onopposite sides of the pivotal point, on the said socket member, a downwardly extending arm formed on each pawl, and a gravity lever mounted in the shell, engaging the downwardly extending arms of said pawls for the purpose of controlling the action of said pawls, with reference to the ratchet, when the socket member is actuated.

14. In a lifting device, an operating mechanism comprising an enclosing shell, a ratchet pivotally mounted in said shell, a socket member pivotally mounted in the shell, a pair of pawls mounted pivotally in the socket member, and each adapted to advance the ratchet, a downwardly extending arm on each pawl, a gravity actuated lever adapted to engage the downwardly extending arms, locking means for holding said lever in an upper and a lower position for the purpose of controlling the direction of revolution of the aforesaid ratchet when the socket member is reciprocated.

15. In a lifting device, an enclosing casing having a pair of diverofing opposed feet, a pair of curved racks rigid throughout their length, and in the same plane mounted therein, a pair of pinions engaging said racks, and mounted in said casing, a pair of bevel gears on said pinions, in combination with an operating means consisting of a shell, a ratchet revolubly mounted in the shell, and a pair of bevel gears mounted thereon adapted to engage the aforesaid pinion bevel gears, a socket member pivotally mounted in the casing, a pair of pawls mounted pivotally on said socket member and in engagement with said ratchet, and means for controllingthe action of the pawls and ratchet for the purpose of raising and lowering the aforesaid racks when the hand lever socket member is reciprocated.

16. In a lifting device, a pair of curved racks rigid throughout their length, mounted in a guiding support, the upper end 0f each of said racks being adapted to move in a rectilinear direction, while its opposite end moves in an arcuate direction, a pair of pinions mounted in the .support each of which engages one of the racks, and a pair of bevel gears on the pinions; an operating mechanism having a shell and a revoluble ratchet mounted in the latter, a socket member pivotally mounted in the shell, a pair of pawls pivotally mounted in the socket member, a gravity lever pivotally mounted in the shell adapted to control the action of said pawls and ratchet for the purpose of raising and lowering the aforesaid racks in relation to their supports.

.17, aliftiilg jack, an operating mechai'io nisin comprising an enclosing shell, a ratchet revolubly mounted in the shell, a socket member pivotally mounted in the same, a pair of pawls pivoted in the socket member, each adapted to advance the ratchet When the rack is being' extended, a downward eX- tension on each pawl, a gravity lever adapted to alternately engage the said pafivl extensions, and control the direction of revolution of the aforesaid ratchet.

18. In a lifting device, a plurality of lifting'jacks, each jack provided with a, casing` having a pair of opposed feet, and a pair of racks rigid throughout their length7 adapted to he extended With their upper ends movingin a vertical rectilinear line, While their lower ends move in an arcuate direction, aV pair or revolulole shafts mounted in the lifting` jack casings, each having a pair of pinions adapted to engage one of the said racks, and means for simultaneously operating the pinions for the purpose of elevating the racks.

In testimony whereof I aix my signature. i

CHARLES T. EARHART. lVitnesses VILLIAM A. HIRTLE, ROBT. V. FULTON.

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