US1990243A - Lifting jack - Google Patents

Description

J. J. MIZER LIFTINGJACK Feb. 5, 1935.

`Filed 001'.. 12, 1954 3 Sheets-Sheet 1 Feb. 5, 1935. J. J. MxzER LIFTING-JACK Filed oct. '12, 1934 5 Sheets-Sheet 2 Illlk mgm Feb. 5, 1935. J. J. MlzER LIFTING JACK Filed oct. 12, 1954 3 Sheets-Sheet 5 Patented Feb. 5, 1935 u l .UNITED-STATES- 1 rrrr.1\1'fr orificel LIFTING JACK Joseph J. Mizer, RacinefWis., assigner to Walker `Manufacturing Company, Racine, Wis., a co1'- poration of Wisconsin Application october 12, 1934, serial No. 748,101

" zo claims. (o1. 254-6) Thisinvention relates to certain newr and useconstructed and operating according tothe prinful'improvements in lifting jacks, and more parciples of this invention. In the accompanying ticularly to an improved jack of the type which is draWngS f i mounted on'a vcarriage and is provided with a Fig. 1 iS a Side elevation Ofthe Complete jaClv. relatively long pgrmanently attached Operating thE eleVated pOSOll Of the lifting lever, 2,150 handle by means f which the jack' maybe pushed alternative positions of the operating handle, beinto position beneaththe load, elevated or lowfA ing indicated irldot'ed lines. l ered and moved while supporting the load. The Fig. 2 isa plan View of the jack, on a larger present improvements are concerned especially scale, a portion of the operating handle being with an` auxiliary mechanism for quickly moving broken away. y the load-lifting element into engagement with Fig. 2a is a plan view of the remainder of the the load before the 'normal lifting koperation is Operating handle, this view being substantially an Started, extension of the right hand portion of Fig. 2.

The lifting jack to which these improvements Fig.' 3 iS a partial Vertical SeCiOIl, this View and claimed in the patent to'Warren Walker, Fig. 2. 1,949,095, granted February 27,1934. Brieflyde- Fig. 4 is a partial vertical 4section o n a` larger, yscribed this jackicomprises 4a carriagein which scale, taken substantially on the samelplane as is mounted a pivoted lifting arm in the form` of Fig. 3.. v y a modiedbell-o'rank lever adapted to support Fig. isa partial vertical section, taken subtheload at the endefiibs longer .arm and pI'Of stantially on the line 5--5 of Fig. 2. Videdinits Shorter aIlTiWiih an internal arcuate Fig. 6 'is a transverse vertical section, on .a rack which is in vmesh with a'rotatable driving larger scale, taken substantially'on the line' 6'-6l pinion mounted on a shaft supported the of Fig;'3. v

` carriage and p0jeeiing,i1hr0ugll`an ODeDiYlgiIi. Fig. 7 yis a perspective View of the pinion and',

the lifting level'. The Operating' handle iS Divratchet assembly, partially broken away. @ted at one end in the carriage and is adapted t0 Fig. 8 is adetail 'elevation of this pinion and be SWlmg 01 Oscillated through a small arc, suitratchet assembly, the ratchet wheel being shownl able pawl andratchet mechanism being interinvertical section. I 30 POSed between the handle and Dinieil SQ that this The carriage comprises a pair of similar( side driving pinion will bey rotated, step by step, in .one frames 1 and 2 which are ofv greatest height addireCtiOn 01' the Other aS the Operating handleis. yjacent their rear ends, and tapered toward the oscillated. v y narrow front end portions which -arefconnected 3;, The improved quick-lift mechanism ycomprises and spaced apart by the front axle 3 which passes- 35;. a second pinion mounted tofrotate with the first through hubs 4 on the side frames and is pinned pinion, a rack suitably guided in the carriage and thereto at 5,. Wheels 6 are journaled on the outmeshing with this second pinion, and a slide mem- Wardly extending ends of the axle 3 and areheld ber mounted on the handle and connected 'with in place by ootter pins 1 or other suitable fastenf this rack; The jack is iirst pushed into position ers. The ends of the side frames projection- 40- beneath the load by means of the handle and then wardly to form feet 8 so that the jack maybe by mOVrlg the Slide member along the handle` stood up on end when not in use.r Rollers 9 are the load-lifting lever is quickly swung upy into journaled on the outwardly projecting end porengagement with the load. The handle is then tions of a rear axle 10 mounted in the rear por- Oscillated and JShe lead lifted Step by step by tion of the side frames. Intermediate portions 45 means 0f the lOaWl and ratchet mechanism. of the side frames f are connected andl spaced The principal object of this invention is to apart by several pins and shafts hereinafter deprovide an improved lifting jack of the ,type scribed. brieiiy described hereinabove and disclosed more The main lifting lever 11 has its forked krear d are applied is substantiallyjof the type disclosed being takensubstantially on the line 3-73 of 15x in detail in the specifications which follow. end porticn formed with a pair of hubs 12;and'13 50'r` Another Objetis t0 DrOVide animDTOVed quiekjournaled on the enlarged central -portion of a lift mechanism fOr lifting .iaClS- fulcrum pin 14 which has reduced end portions Other objects and advantages of this invention 15 extending through bosses 16 formed on the will be more apparent from the following detail respective side frames, the fulcrum pin being description of one approvedform of mechanism clamped in position between the side frames by 5 5' means of nuts 17 threaded on the opposite end portions of the pin. Thisk lifting member also comprises a rack segmentA 18 having an upper central hub 19 positioned in the fork of the lever and journaled on pin 14 between the hubs 12 and 13, and having its forwardly extending upper portion 20 secured by rivets 21 and 22 between downwardly extending flanges 23 of the main lever member `11. The downwardly extending portion of segment 18 is formed beneath the hub 19 with an opening, and a concave internal rack` or gear segment 24 is formed in the lower portion of this opening. This rack is arcuate andV substantially centered in the axis of fulcrumpin 14, the several teeth 25 ofthe rackprojeeting inwardly and upwardly toward this fulcrum pin or axis. The lever 11 and segment 18 are rigidly connected, as already described, so as to' form .a single bell-crank lever mechanism which is adapted to swing about the fulcrum pin 14. The long forwardly projecting arm of the bell-crank is pivoted at26 to the lifting head or cap 27which maybe of any desired form and is preferablyv provided with the spaced apart upwardly extending load-supporting fingers 28.` A pair of similar sider links 29 have .their forward ends pivoted at 30 to the head 27 and their rear ends pivoted at 31 to the respective side frames 1 and 2. These links cooperate with the lever 11 to give a parallel motion to the load-supportinghead 27 so as. to`

keep the head horizontal` in all of its 'raised' or lowered positions. The head is shown lowered lin Figs.V 1 and 3 and is shown in dotted linesin its elevated position in Fig. 1.: It will be noted that when this head is lowered to its extreme position it is substantially no higher than the tops of the central portion of shaft 32 (see Figs. 6, 7 and 8) y comprises the main driving pinion 36 which 4meshes with the teeth 25 of the internal rack 24 in the lifting lever.` The ratchet -wheel 37 'is' broached out tot over1 one reduced end portion 38 of pinion 36, the teeth of the pinion forming keys for rigidly securing the ratchet wheel 37 to the pinion. The auxiliary pinion 39 (which forms` a portion cf the' quick-lift mechanism hereinafter described) ,is also rotatablyv mounted on shaft 32 and is formed in one side with slots to receive the lugs 39 extending from the end of drivingpinion 3ft-opposite from the ratchet 37. This Vwill cause the two pinions 36 and 39 t0 rotate as a unit. This rotating assembly is so positioned on the yshaft 32 that the maindriving pinion 36 will be within the opening in the segment 18 and mesh with the internal rack, whereas the ratchet wheel 37 will be positioned at one side of the bell-crank'and the second pinion 39 at the opposite side.

Theoperating handle comprises a yoke casting 40 having forwardly extending side portions 41 and 42 which are journaled at their inner ends onthe shaft 32 at the respective sides of the rotating assembly previously described, and just inside of the` side frames 1 and 2 respectively; The similar side bar members 43 and 44 Of the handle are secured at their forward ends in the" recessed outer sides of the yoke casting v40 by means of bolts 45. The side bars 43 and 44 converge inwardly and rearwardly toward one another and are secured by bolts 46 to the opposite sides of the inner end of the handle extension bar 47. (See Fig. 2a). 'Suitable handle members 48 of wood` or other suitable material are secured to the opposite sides of thev extreme outer or rear end of the bar 47 thus complet-` ing the operating lever. In order to manipulate the raising and lowering mechanism, this operating handle is adapted to be reciprocated or of the .side arms (in the present example arm` 42) with a stop screw 50 mounted inV a lugy51 extending inwardly fromside `frame 2. A continued upward movement of the Vhandle after it has engaged with stop 50 will raise the rear endV ofthe carriagek so as to support-same entirelyj by the front wheels 6 and thus facilitate moving the carriage in position.

An operating pawl or dog 521s journaledpn a stud 53 mounted in the handle yoke arm 41 `so that the pawl will be positioned substantiallyin` the vertical plane of ratchet wheel 37.` This pawl has a tooth 54 shaped to engage the teeth of vratchet 37 and is formed with a lugorvpro-` jection 55 on one side thereof to cooperate with the rotary reversing memberv hereinafter de scribed. A'torsion spring 56"'is anchored at one end andengages thepivotedpawl at the other to swing the pawlinto' engagement with ratchet Wheel 37 at all times. A holding pawl 57, which may be similar in all respects to the operating pawl 52, ismounted on a pin 58 whichis mounted in the opposite side frames land 2. Suitable spacers position the holdingpawl 57 so that it willalso be in the verticalplane of ratchet wheel 37. yThe holding pawl is normally forced yieldingly into engagement with the ratchet wheel by meansof torsion spring 59. n

In order ltoelevate the head n carried thereby, the operating handle is oscillated orV swung up and down. During the downward stroke the operating pawl`52'will engage a tooth of ratchet wheel 37 and cause the ratchet wheel and driving pinion 36 to rotate with the handle through this short downward arc thus swinging the lifting bell-crank'upwardly through a short arc. The holding pawl 57 will snap outwardly over the teeth of the ratchet, :but will engage another tooth of Vthe ratchet Wheel to hold the load elevated during the succeeding upward movement of the operating handle, during which movement the operating pawl 52 will ride outwardly over thek teeth of the ratchet wheel. In'ths manner, continuous swinging movement of the operatinghan dle will cause a 'step by step upward swinging movement of the lifting r.bellcrankuntil head 27'has been raised to the elevated positionshown the lifting head and the load supported thereby.A

This reversing mechanism comprises a rotary reversing member 60 which has a hub 61 journaled 2v, and theV 10aa` through bushing 62 on the shaft 32 between the ratchet wheel :37 and the `handle arm .41;v Thisy reversing member is formed with a'pair ofqoutwardly projecting ngers or cam members 63 and 64 which, in certain positions of the reversing member, are adapted to engage and cooperate with the lugs onthe respective pawls' 52 and` 57. A link or rod 65 has one end portion pivot-.v allysecured in an ear 66 projecting upwardly from reversingmember 60, the rod projecting rearward-w ly through 'a guide opening 67 in the handle-yoke structure and being pivotally connected :with an ear.68 projecting upwardly. from the casing 69 which houses thereversing spring 70. The spring 70 surrounds the inner end port'ion of a link or rod71.which projects `throughthe rear end of casing 6 9, the spring beingconned between this end of the casing and a nut 72 adjustably threadedon rod 71. The rear end of rod 71 is secured toaslide member A73 mountedon the side handle bary 43` (see Fig. l). `A reversing lever 74 is piv otally mounted in a y bracket 475 secured to one side of handle bar 47 adjacent the hand grip 48. link or rod 76 connects the reversing lever i '14 with the slide member 73. v

During the normal elevating operation ofthe jack the reversing lever 74 is swung forwardly to the positionfshown in Figs. 1 and 2a. When the lever is in this position the reversing spring 70 is not under compression, and as the operating handle is oscillated up and down the reversing cam /wi1l swing idly with the handle and the reversing lugs 63 and 64 will remain out of engagement with the lugsy 55 on the pawls, and these pawls opa crate as already described to permit a step by step tain times. AAs a result, the holdingpawl 57 will be held out of engagement with ratchet'37 during a portion of the upwardgstroke of the handle so as to permit the load to be lowered, and the operating pawl 452"willbe held out during the-succeeding downward stroke of the handle, atwhich time vthe pawl-157xwill again engage the ratchet to hold the load in its partiallylowered position.

The operation of this reversing mechanism is describedvv more in detail in the Walker Patent 1,949g095hereinabove referred to, in which this reversing mechanism is disclosed' and claimed. The lifting jack as thus fardescribed is substantially the same, except for certain improvements in design, as the one disclosed and claimed in said Walker patent. The improvements of this present invention are concerned more especially with the novel quick-lift mechanism now about to be described. f

, Since this jack is very powerful, the elevating movement of the lifting head is necessarily pron portionately slow, and it is desirableto provide means for quickly elevating the head until it is inposition to engage the load. 'For this purpose the auxiliary quick-lift. mechanism is provided. The reciprocatorybar 77 is guided at 73 (see Fig. 5) Ain the. handle yoke frame 40 and the forward underportion of bar 77 is formed with a rack '.79

. which meshes with the auxiliary pinion 39 already described. A link or push-md80 is pivotally connected at one end 81 with. the rear end of bar 77,k and is pivotally `connected at its :other end 82 with aslide member 83 mountedon the handleV bar 47 Vso as to be movable longitudinally thereof; The slide 83 is provided with suitable laterally extending hand grips 84 or other means bywhich the slide 33 maybe conveniently moved longi.

tudinally of the handle.

vWhen the jack has been` pushed into proper position beneath the automobile axleV orV other load to be lifted, the operator will graspthe handle 84 on slide 83 andpull'this slide rearwardly along the operating handle 47, this pull being transmitted through rod 80 to the rack `79 which will rotate the pinions 39 and 36 and cause the lifting bell-crank to be swung kquickly .up-

wardly so` as to swing the lifting head 27 into.

engagement with the load. During this, opera-I tion the pawls 52 and 57.will simply ride over the ratchet teeth of ratchet wheel .37. /As soon. as the load is engaged the handle 84 will be released andthe remainder of theA lifting operationwill be accomplished by'swinging or `oscillating the operating handle up and down in the manner already described. During this additional lifting movement the rack 79 will' be moved rearwardly slowly by the rotation of pinicn39-`with vthe driving pinion 36, and the slide member 73 will .be moved idly along the handle bar 47.'

When the jack is lowered the slide 83 will,r in' a ICOSv reverse manner, be moved along the handle bar 47 in an oppositeA direction by the pull transmitted through rod 80 from rack 79. It will be apparent that this improved quick-lift'fmechanism is very simpleand effective, and is's'elf-l reversing so vthat the. device will always be in position to impart a quick lift to the bell-crank when such movement is desired.

^ lt will be noted that the 4operations of this jack` arefcontrolled entirely from the handle, and that anoperator positioned adjacent the rear end of thehandle canmanipulate the jack into position beneath the load, quickly raise the lifting head `into engagement with n.the load, and then raise and lower the load, wthoutfchanging his position.

I claimz. y

1. In alifting jack, a supporting membeiyaA vload-lifting member. 'movably mounted in the supporting member and. comprising a rack, a pair supporting member and comprising a rack, a pair of connected pinions ro-tatablymounted inthe supporting member, one of the pinions meshing with the rack, a second rack. meshing .withthe second pinion, a handle pivotally connected with the supporting member, and means carried 'by the handle for tudinally.

3. In a liftingv jack, a supporting member, a

load-lifting member movably mounted ,inl the moving the second 'rack longil-J supporting memberand comprising a rack, a pair of connected pinions .rotatably mounted in the" supporting member, one of the'pinionsmeshing with the rack, a second rack meshing with the second pinion, a handle'pivotally connected with the supporting member, a slide member mounted on the handle for movement longitudinally thereof, and a pull-rod connecting the slide member and the'second rack. l

4. In a lifting jack, a `supporting member, .a load-lifting lever pivotally mounted in the supporting member and comprising an arcuate rack,

a pair of connected pinions rotatably mounted in the supporting member, one of the pinionsmeshing with the rack, a second rackmeshing .with the second pinion, and means for moving the second rack longitudinally.

5. In a lifting jack, alsupporting member,v a-

load-lifting lever pivotally mounted in the supporting member and comprising an arcuate rack, a pair of connected pinions rotatably mounted in the supporting member, one of the pinions meshing with the rack, a secondA rack meshing with the second pinion, a handle pivotally connectedy with the supporting member, and means carried.'

' ymoving the second rack longitudinally.

'7. In a lifting jack, a carriage, a load-lifting lever pivotally mounted in the carriage and com'- prisingan arcuate rack, a pinion rotatably supv ported in the carriage and meshing With the arcuate rack, a second pinion rotatable with the first pinion, a lrack meshing with the second pinion, a handle pivotally connected with the carriage, a slide membervmounted on the handle for movement longitudinally thereof,` and a pullrod connecting the slide member with the second rack.

8. In a lifting jack, a carriage, a load-lifting lever pivotally mounted inthe carriage and comprising an internal arcuate rack, a pinion rotatably supported in the carriage and'meshingwith' the arcuate rack, a second pinion rotatable with the first pinion, a rack meshing with the secondiV pinion, a handle pivotallyl connected with the carriage, and means carriedb-y the handle for moving the second rack longitudinally.

y 9. In a lifting jack, a carriage, a load-lifting member mounted in the carriage and comprising a rack, a pair of connected pinions rotatably mounted in the carriage, one of the pinions .meshing with the rack, a' second rack meshing with the secondy pinion, a handle pivotally .connected With the carriage, and means carried by the handle for moving the second racklongitudinally. f 4

10. In a lifting jack, a carriage, a load-lifting member mounted in the carriage and comprising a rack, a pair ofy connected pinions rotatably mounted in the carriage, one of the pinions meshingwith the rack, a second rack meshing with the second pinion, a handle pivotally connected with the carriage, a slide member mounted on the handle for movement longitudinally thereof, and a pull-rod connecting the slide member and the second; rack.

' y11; Ina lifting jack, a supporting'member, a

" load-lifting member movably mounted in the supporting member and comprising ak rack, a pinion rotatably mounted in the supporting member and meshing with the rack, va handle` pivotally cona carriage, a load-liftingk nected with therst pinion, a second rackmeshl" ing with thesecond pinion, and means-carried by the handle formoving the lsecond rack longitudinally. "f

12. In a lifting jack, a load-lifting member movably' mounted in vthe supporting. member and comprising a rack, va pin# ion rotatably mounted in the supportingrme'mbri and meshing with lthe rack, a handle'pivotally connected with the supporting member, means actuated by oscillation' ofthe handle Afor impartingstep-by-step rotationto' the pinion, and` a quick-lift mechanism comprising `a :SecondSpin-'f ion connected with the rst pinion, asecondrak' meshing with the second pinion,aslide member nally thereof, and a pull-rod connecting' the'slide member and the secondrack. 4 7* 5? 13. In a lifting jack', a supporting member, a load-'lifting lever pivotally mounted in the ,sup-I porting member and comprisinglan arcuate'rack,` a pinion rotatably mounted in the supporting member and meshing with the rack, a handle pivotally connected withv the supporting member,

means actuated by oscillation .of the handle' for imparting step-by-step rotation to th'e'piniomand a quick-lift mechanismv comprising'a second pin- `ion connected With the first pinion, a second' rack meshing with the second pinion, and means carried-by the handle for moving the secondracl" longitudinally. l

14. In a lifting jack, a carriage, a `10a'd-'iiftnygv member movably mounted in the carriage]andk comprisingja rack, a pinion rotatablymounted `15.`In a lifting jack, a carriage, afload-lifting" member movably'mounted inthe carriage' `and `comprising araclr,l a pinion rotatably mountedy in the carriage and meshingwith"th`e rack, "a

handle pivotally connected Yfvvith* the carriage, means actuated by 'the oscillation of the handle for imparting step-by-step rotationgrto'the bpinion, and a quick-lift mechanism comprising a second pinion connected with the first pinion,-a sec"-y ond rack meshing with the second pinion,va slide suPDOrting member, a,

mounted on the handle for movement longitudi--.

member mounted on'the handlorfmovement longitudinally thereof, and" ai pull-rodi connecting the slide member andthe second ra`ek.i"3 f 16. In a lifting jack, a carriage, 'a load-lifting lever pivotally mounted in the carriage and comprising an arcuate rack, a pinion rotatably mounted in the carriage and meshing'withtherack, a handle pivotally connected with the A`carriage, means actuated by oscillation of the handleffor imparting step-by-step rotation` to the pinion, and a quick-lift mechanism comprising a second pinion connected Withthe. first pinion, a second rack meshing with the second pinion,`and meansy carried by the handle for moving kthe second rackv longitudinally. f z. u

17. In a-lifting jack, a carriage,l a load-lifting lever pivotally mounted in the carriage 'andrcomprising an-internal arcuate rack, a` .pinionrrotat-I ably mounted in the carriage and meshing with the rack, a handle pivotally yconnected Withthe carriage, means actuated by oscillation ofthe handle for imparting step-by-step rotation tothe pinion, and a quick-lift mechanism comprising a second pinion connected with the first pinion, a second rack meshing with the second pinion, and means carried by the handle for moving the second rack longitudinally.

18. In a lifting jack, a carriage, a load-lifting lever pivotally mounted in the carriage and comprising an arcuate rack, a pinion rotatably mounted in the carriage and meshing with the rack, a handle pivotally connected With the carriage, means actuated by oscillation of the handle for imparting step-by-step rotation to the pinion, and a quick-lift mechanism comprising a second pinion connected With the first pinion, a second rack meshing with the second pinion, a slide member mounted on the handle for movement longitudinally thereof, and a pull-rod connecting the slide member and the second rack.

19. In a lifting jack, a carriage, a load-lifting lever pivotally mounted in the carriage and comprising an internal arcuate rack, a shaft mounted in the carriage, a pinion on the shaft meshing with the rack, a ratchet-wheel on the shaft rotatable with the pinion, a holding pawl mounted in the carriage and engaging With the ratchet,l

a handle pivotally mounted in the carriage, an actuating pavvl mounted on the handle and engaging with the ratchet, a reversing mechanism adapted to engage the pawls, means for alternatively positioning the `reversing mechanism sov kthat oscillation of the handle will either raise or lower the lifting lever step-by-step, and a quicklift mechanism comprising a second pinion rotatable vvith the first pinion, a second rack meshing with theA second pinion, and means carried by the handle for moving the second rack longitudinally. y

20. In a lifting jack, a carriage, a load-lifting lever pivotally mounted in the carriage and comprising an internal arcuate rack, a shaft mounted in the carriage, a pinion on the shaft meshing with the rack, a ratchet-Wheel on the shaft rotatable With the pinion, a holding paWl mounted in the carriage `and engaging with the ratchet, a handle pivotally mounted inthe carriage, an

actuating pawl mounted on the handle and engaging with the ratchet, areversing mechanism ed onvthe handle formovement longitudinally thereof, and a pull-rod connecting the slide member and the second rack. JOSEPH J. MIZER.

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