US2439781A - Hand lift truck - Google Patents
Hand lift truck Download PDFInfo
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- US2439781A US2439781A US520186A US52018644A US2439781A US 2439781 A US2439781 A US 2439781A US 520186 A US520186 A US 520186A US 52018644 A US52018644 A US 52018644A US 2439781 A US2439781 A US 2439781A
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- Prior art keywords
- lifting
- steering
- head
- elevating platform
- handle
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62B—HAND-PROPELLED VEHICLES, e.g. HAND CARTS OR PERAMBULATORS; SLEDGES
- B62B3/00—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor
- B62B3/04—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor involving means for grappling or securing in place objects to be carried; Loading or unloading equipment
- B62B3/06—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor involving means for grappling or securing in place objects to be carried; Loading or unloading equipment for simply clearing the load from the ground
- B62B3/0625—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor involving means for grappling or securing in place objects to be carried; Loading or unloading equipment for simply clearing the load from the ground using rigid mechanical lifting mechanisms, e.g. levers, cams or gears
Definitions
- This invention relates to an industrial truck of the type in which an elevating platform is lifted relatively to a lifting head or main frame by lifting means actuated relatively to the lifting head. More particularly, my invention relates to a truck of the class described in which the lifting mechanism comprises mechanically actuated means carried on the lifting head and adapted to apply lifting effort to the elevating platform whereby to raise that platform relatively to the lifting head.
- an elevating truck of the single frame type that is, a truck in which the elevating platform is mounted at its forward end relatively to a lifting head so that the forward end of the platform is lifted relatively to the lifting head by means on the lifting head, while the rear end ofthe elevating platform is raised through load wheels pivotally supported at that rear end and actuated through suitable mechanism extending toward the lifting head.
- My Patent No. 2,274,- 164 I illustrate a single frame truck of the class described.
- the invention of this application resides particularly in a new type of lifting mechanism that is extremely simple and yet contributes features that have long been desired in the hand lift truck industry.
- One feature of the invention resides in the means whereby a compound lifting action takes place through the downward swinging of a lifting lever that is preferably the steering handle of the truck.
- the downward swinging movement of the steering and lifting handle first operates at a lower rate of mechanical advantage to impart relatively swift movement to the elevating platform while the latter part of the swinging movement of the handle actuates the lifting mechanism at a higher mechanical advantage to lift the elevating platform at a relatively lower rate.
- the conception of a compound lifting mechanism is old in the art, my invention residing in the particular compound lifting mechanism I have developed and the manner in which it is associated with a lifting member it is adapted to actuate.
- the lifting member and the compound lifting mechanism are rotated together with the steering and lifting handle so as to be effective in all steering positions of the handle, and with the lifting member applying lifting thrust to a part ofthe elevating platform in all steering positions.
- a further feature of my invention resides in means whereby the operative connection between the lifting member and the steering and lifting handle may be controlled to release the steering and lifting handle from the lifting member to contribute a free handle.
- This feature of my invention is old in the art.
- the novelty of my-invention resides not only in the structure I have conceived, but also in the arrangement of the feature between a lifting member and a lifting handle that are both mounted on the lifting head of a truck.
- the lifting member and the steering handle are both mounted on what is termed the steering head of the truck for rotation together.
- a further feature of my invention resides in the arrangement of the means of connection between the lifting member and the lifting handle so that the said means of connection are controlled by the downward movement of the elevating platform to bring the liftin member and the lift means of the steering and lifting handle into operative engagement.
- FIG. 1 is a general elevation of a truck to which my invention is shown applied.
- Fig. 2 is a vertical partial section through the front end of the truck showing the elevating platform lowered.
- Fig. 3 is a view of certain parts of Fig. 2 showing the elevating platform partly elevated and with the compound lifting mechanism about to lift the platform at a higher mechanical advan 3 tage than during the first part of the lifting operation from Fig. 2 to Fig. 3.
- Fig, 4 is a view of the parts of Figs. 2 and 3 showing the elevating platform fully elevated.
- Fig. 5 is a section taken along lines 5-5 of Fig. 2.
- Fig. 6 is a section taken along lines 6-45 of Fig.2.
- FIG. l I show there a single frame truck comprising an elevating platform It and a lifting head designated generally by reference numeral ii, there being several, such reference numerals H applied to the lifting head in order to indicate better its outline.
- the forward end of the elevating platform. Ill is formed with a vertical standard 12 as is well shown in Figs. 1, 2 and 3, the standard being welded to the elevating platform or otherwise-secured thereto as manufacturing technique may make desirable.
- the upper end of the standard l2 is'formed with a pair of brackets l3 supporting a shaft [4 (Figs. 5 and 6), the said shaft l4 formingbearlugs for the inner ends of the upper parallel connecting links l5.
- the opposite ends of the links I5 are secured-as by welding to a sleeve l6 that is mounted through suitable bushings for rotation about a shaft I! carried in bearings 18 formed on the upper ends of brackets if! that are an integral part of the lifting head II'.
- the elevating platform lll' may be said to be pivoted at-the upper end of its standard l2 relatively to the lifting head I I through the inter mediary of upper parallel links ii.
- the opposed links 22 are welded to a sleeve 22a (Fig.6) and are thereby pivoted relatively to a shaft 23 mounted on the lower bracket portions 24 of the lifting head as best shown in Figs. 2 and 4.
- the mechanism whereby links 22 are pivoted about shaft 23 is the mechanism preferably used for linkage mounting throughout the truck.
- the links 22 are pivoted to a pair of rods 26 that extend rearwardly to rear wheel supporting links 21 as best shown in Fig. 1.
- the links 21 carry the rear lifting wheels 28 of the elevating platform land are adapted for rotation about pivot shafts 29.
- a holding strut 39 best shown in Figs. 2, 3 and 4.
- This strut 30 is pivoted about the shaft M on which the inner ends of the links [5 are mounted, and between the said links, as best shown in Fig. 6.
- the holding shaft 3i supports a treadle 32 pinned thereto, and is maintained normally in the position of Fig. 2 by a spring 33 secured at one end to the pin 34 of arm 35 integral with the treadle and shaft-3
- the holding mechanism is not part of vating platform relatively to the lifting head about lower links 22 and the upper links is from the position of Fig. 2 to the position of Fig.
- a dashpot 36 is utilized to cushion the downward movement of the elevatingplatform when the holding mechanism just described releases it for movement. Since the dashpot and its supporting mechanism is not part of the invention herein claimed, it is not thought necessary to describe it in detail here.
- the lower end of the dashpot is pivoted about a shaft 38a supported in brackets 31 and 38 formed integrally with the lifting head H.
- the piston of the dashpot designated by reference numeral 39, is secured to a block 40 that .is formed with a rounded end 41 as best shown in Fig. 4, for cooperation with a bracket 42 that is an integral part of the standard. 12.
- the lifting head H of my truck is adapted to support what is termed in theart a steering head.
- This steering head comprisesv a main casting 45 formed with a sleeve portion; that through the intermediary of a bushing 4'! rotates-relatively to the tubular portion 48 of the lifting head H.
- the sleeve portion 48 supports the steering wheels in a conventional manner as illustrated.
- a steering and lifting handle assembly is designated by reference numeral 49, and is supported by a shaft 50, secured to its casting portion 51, for rotation on bearings 5
- the handle 52 of thesteering and lifting handle assembly 48 is hollow for the housing of a handle balancing mechanism such as is well shown and described in my Patent No. 2,093,392, dated September 14, 1937.
- the balancing mechanism of the handle comprises a pair of links 53 pivoted at 54'to the steering head casting 65, the said links 53 supporting about pivot 55 a roller 56, the functioning of which will presently be indicated. It is merely necessary to appreciate at this time that the arrangement of the handle balancingmechanism is such that the handle is yieldingly maintained in its position of Fig. 2 with the'roller 56 also in the position shown inFig. 2.
- the casting 51 of the steering and lifting handle assembly 49 supports a shaft 58 on which is pivoted a link 59.
- the link 59 in turn has pivoted thereto, through the pin 66, an actuator for
- the actuator takes the form of a lift hook 6
- the main casting 45 of the steering head carries a bearing shaft 62 on which is adapted to be supported a lifting member designated generally by reference numeral 63.
- This lifting member 63 is in the form of a bell crank fabricated from a pair of parallel plates 64 pivoted on the shaft 62 and held together by the pins 65 and 66.
- Pin 65 is termed a lift pin, and cooperates with lift hook 6
- Pin 66 supports a thrust roller 61 that cooperates with a. boss 68 secured to the end of a bracket 69.
- the bracket 69 is formed as an integral part of the elevating platform, as is probably best illustrated in Figs. 2, 4 and 6, and is so arranged that its boss 68 overlies the steering axis of the steering head in all positions of the elevating platform.
- the boss 68 has sufficient area so that it cooperates with the thrust roller 61 in all posi tions of that thrust roller, it being appreciated, as will be hereinafter set forth in more detail, that the thrust roller 61 rotates with the steering head and is maintained as closely as possible to the steering axis.
- Fig. 2 we note there that the elevating platform is in its fully lowered position and that the steering and lifting handle assembly 49 is in its vertical position. With the parts located as in Fig. 2, the roller 56 of the handle balancing mechanism operates against the tail 59a of the link 59 for holding that link in its illustrated position against the force of gravity. It will also be seen that the boss 68 presses downwardly on the thrust roller 61, and that thrust roller 61 in turn presses against the tail 6
- a lever 15 functions to limit the drop of the lift hook 6
- a treadle 16 is secured to a shaft 11 fixed to the lever 15. the shaft 11 being supported as best seen in Fig. 5 by suitable bearings 18 on the steering head. With this arrangement of the parts, depression of the treadle 16 will bring the lift hook 6
- the treadle i6 and lever 15 may also be useful where an intermediate lift is desired, in which case the strut 36 will be made to hold the elevating platform in more than one elevated position. Because this structure is not claimed in this application no further showing v thereof is thought necessary here.
- a lifting truck a lifting head, an elevating platform, means mounting said elevating platform for lifting movement relatively to said lifting head, a lifting member for lifting said elevating platform movably mounted on said lifting head, a part of said elevating platform extending over said lifting member for engagement thereby in all positions of said elevating platform,
- a steering and lifting handle pivoted on said lifting head for vertical swinging movement, a link pivoted on said steering and lifting handle, means pivoted on said link adapted to engage and disengage said lifting member, and movable upon downward swinging of said steering and lfting handle when engaged with said lifting member for moving said lifting member to contact the part of said elevating platform to lift said eleve ing platform.
- a lifting head an elevating platform, means mounting said elevating platform for lifting movement relatively to said lifting head, a steering head rotatable on said lifting head, a bell crank pivoted on said steering head and having a thrust imparting portion thereon, a boss secured as a part of said elevating platform and overlying said thrust imparting portion in all steering positions of said steering head and in all positions of said elevating platform, a steering and lifting handle pivoted on said steering head for downward swinging movement, a link pivoted on said steering handle, a hook pivoted to said link and adapted to engage a part of said bell crank to rotate said bell crank when the steering and lifting handle swings downwardly, whereby through said thrust imparting portion and boss to lift the elevating platform, said hook being biased normally out of engagement with said part but adapted to be held in engagement therewith by the stress therebetween incidental to the lifting operation, the relieving of said stress as after the elevation of said platform allowing separation of said hook from said bell crank part to contribute a free steering and lifting
- a lifting head an elevating platform, means mounting said elevating platform for lifting movement relatively to said lifting head, a steering head rotatable on said lifting head, a bell crank pivoted on said steering head and having a thrust imparting i portion thereon, a boss secured as a part of said elevating platform and overlying said thrust imparting portion in all steering positions of said steering head and in all positions of said elevating platform, a steering and lifting handle pivoted on said steering head for downward swinging move- 'ment, a link pivoted on said steering handle, a
- hook pivoted to said link and adapted to engage a part of said bell crank to rotate said bell crank when the steering and lifting handle swings downwardly, whereby through said thrust imparting portion and boss to .lift the elevating platform, said hook being biased normally out of engagement with said part but adapted to be held in engagement therewith by the stress therebetween incidental to the lifting operation, the relieving of said stress as after the elevation of said platform allowing separation of said hook from said bell crank part to contribute a free steering and lifting handle, and means whereby said hook is moved toward engagement with said bell crank part when said elevating platform is lowered.
- a lifting head an elevating platform, means mounting said elevating platform for lifting movement relatively to said lifting head, a steering head rotatable on said lifting head, a bell crank pivoted on said steering head and having a thrust imparting portion thereon, a boss secured as'a part of said elevating platform and overlying said thrust imparting portion in all steering positions of said steering head and in all positions of said elevating platform, a steering and lifting handle pivoted on said steering head for downward swinging movement, a link pivoted on said steering handle, a hook pivoted to said link and adapted to engage a part of said bell crank to rotate said bell crank when the steering and lifting handle swings downwardly, whereby through said thrust imparting portion and boss to lift the elevating platform, said hook being biased normally out of engagement with said part but adapted to be held in engagement therewith by the stress therebetween incidental to the lifting operation, the relieving of said stress as after the elevation of said platform allowing separation of said hook said lifting head, a bell crank pivoted on said steering
- a lifting head an elevating platform, means mounting said elevating platform for lifting movement relatively to'said lifting head, a steering head rotatable on said lifting head, a bell crank pivoted on said steering head and having a thrust imparting portion thereon, a boss secured as a part of said elevating platform and overlying said thrust imparting portion in all steering positions of said steering head'and in all positions of said elevating platform, a steering and lifting handle piv oted on said steering head for downward swinging movement, a link pivoted on said steering handle, a hook pivoted to said link and adapted to engage a part of said bell crank to rotate said bell crank when the steering and lifting handle swings downwardly, whereby through said thrust imparting portion and boss to lift the elevating platform, said hook being biased normally out "of engagement with saidpartbut adapted to be held in engagement therewith by the stress therebetween incidental to the lifting operation,- the relieving of said stress as after the elevation of said platform allowing separation of saidhookfromi-said
- a-lifting head in a truck-of the classcdescribed, a-lifting head,zan elevating platform; means mounting said elevating platform for lifting movement relatively to said lifting head, a steering'head rotatable on said lifting head, a bell crank pivotedon said steering head and having athrust imparting portion thereon, aboss secured as a part of said elevating platformand overlying said thrust im'- parting ortion in all steeringpositions of said steering head and in all positionsof said elevating platform, a steering and liftinghandle pivoted on 25 saidsteering head for downward swinging movement, a link pivoted on said steering handle, .a hook pivoted tosaidlink and adapted to engage a part of said bell crank to rotate said bell crank-- when the steering and lifting, handle swings 3Q downwardly, whereby; through said thrust imparting portion and boss to lift the elevatin D1atform, said hook being biased normally out engagement with said part but adapted to behold in: engagement therewith bythe "stress therebe twe
- a lifting head, an elevatingplatform, means mounting
- crank part tocontribute a free steering and lift lnghandle, and means whereby said hook, is positionedfautomatically to effect, engagement of said hook with said bell crank partby the lowering movement of said elevating'platform.
- a lifting head In a truck of the class'described, a lifting head, an elevating platform, means mounting said elevating platform for lifting movement relatively to said liftinghead, a steeringhead rotatable'on said lifting head, a bell crank pivoted on said steering head'and having a thrust impartlo'ing portion thereon, a-boss secured as a part of said elevating platform and overlying said thrust impartingportion in all steering positions of said steering head and in all positions of said elevat ing platform, a'steering and lifting handle pivoted on said steering head for downward swinging movement, a hook movable with said steering and lifting handle and adapted to engage a part of said bell crank to rotate said bell crank when the steeringand lifting handle swings downwardly, whereby through said thrust imparting 18.
- a lifting need an elevating p1atform,means mounting said 1 ;,elevating platform for lifting movement relatively to said lifting head, a. steering head rotatable on said lifting head, ,a bell crank pivoted on said steering head and having a thrust imparting portion thereon, a boss secured as a part of said ele- 40 vating platform and overlying said thrust imparting portion in all steering positions of said steering head and in all positions of said elevating platform, a steering and lifting handle pivoted on saidsteeringhead for downward swinging move- 4o ment, a link pivoted'relatively to said steering handle and adapted to engage a part of said bell crank to rotate said bell crank when the steering and lifting handle swings downwardly, whereby through said thrust imparting portion and boss to liftthe elevating platform, said link being biased normally out of engagement with said part but 'adaptedto be held in engagement therewith by the stress therebetween incidental to the liftingoperation, therelieving of said stress as after the elevation of said
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Description
April 13, 1948; 5 QUAYLE HAND L IFT TRUCK- Filed Jan. 29, 1-944" 4 Sheets-Sheet 1 INVENTOR Gepr e Quay/ ATTORNEY Aprii 13, 11948.
G. 'QUA YLE ,781 7 HAND LIFT TRUCK v Filed Jan. 29, 1944 4 Sheets-Sheet 2 5; .2. v V 4 5+ 52 l 45 I -v I Y V INVENTOR BY G e 4 1 ATTORNEY April 13, 1948. I QUAYLE 2,439,781
HAND LIFT TRUCK Filed'Jan. '29, 1944 4 sheets-sheet '5 INVENTOR a my 2 Que ATTORNEY April 13, 1948.
G. QUAYLE HAND LIFT TRUCK Filed Jan. 29, 1944 4 Sheets-Sheet 4 K L m T%m c Y Patented Apr. 13, 1948 HAND LIFT moon George Quayle, Philadelphia, Pa., assignor to The Yale & Towne Manufacturing Company, Stamford, Conn., a corporation of Connecticut Application January 29, 1944, Serial No. 520,186
18 Claims. (Cl. 254-2) This invention relates to an industrial truck of the type in which an elevating platform is lifted relatively to a lifting head or main frame by lifting means actuated relatively to the lifting head. More particularly, my invention relates to a truck of the class described in which the lifting mechanism comprises mechanically actuated means carried on the lifting head and adapted to apply lifting effort to the elevating platform whereby to raise that platform relatively to the lifting head. In setting forth my invention, I shall describe it as applied to an elevating truck of the single frame type; that is, a truck in which the elevating platform is mounted at its forward end relatively to a lifting head so that the forward end of the platform is lifted relatively to the lifting head by means on the lifting head, while the rear end ofthe elevating platform is raised through load wheels pivotally supported at that rear end and actuated through suitable mechanism extending toward the lifting head. In My Patent No. 2,274,- 164 I illustrate a single frame truck of the class described.
The invention of this application resides particularly in a new type of lifting mechanism that is extremely simple and yet contributes features that have long been desired in the hand lift truck industry. One feature of the invention resides in the means whereby a compound lifting action takes place through the downward swinging of a lifting lever that is preferably the steering handle of the truck. Thus, the downward swinging movement of the steering and lifting handle first operates at a lower rate of mechanical advantage to impart relatively swift movement to the elevating platform while the latter part of the swinging movement of the handle actuates the lifting mechanism at a higher mechanical advantage to lift the elevating platform at a relatively lower rate. The conception of a compound lifting mechanism is old in the art, my invention residing in the particular compound lifting mechanism I have developed and the manner in which it is associated with a lifting member it is adapted to actuate.
As a further features of the invention, the lifting member and the compound lifting mechanism are rotated together with the steering and lifting handle so as to be effective in all steering positions of the handle, and with the lifting member applying lifting thrust to a part ofthe elevating platform in all steering positions.
A further feature of my invention resides in means whereby the operative connection between the lifting member and the steering and lifting handle may be controlled to release the steering and lifting handle from the lifting member to contribute a free handle. Those skilled in the art will of course appreciate that broadly this feature of my invention is old in the art. The novelty of my-invention resides not only in the structure I have conceived, but also in the arrangement of the feature between a lifting member and a lifting handle that are both mounted on the lifting head of a truck. As a more particular feature of the invention, the lifting member and the steering handle are both mounted on what is termed the steering head of the truck for rotation together. Heretofore, where such means of connection have been susceptible to disconnection for contributing a free handle,
they have extended between the lifting member and the elevating platform rather than between parts of the lifting mechanism per se.
A further feature of my invention resides in the arrangement of the means of connection between the lifting member and the lifting handle so that the said means of connection are controlled by the downward movement of the elevating platform to bring the liftin member and the lift means of the steering and lifting handle into operative engagement.
I have thus described generally the main features of my invention in order that a better understanding of the relation of my invention to the prior art may be had. There are of course additional valuable features inherent in my invention that I have not, up to this point, outlined, because those features will best be understood from the specific disclosure that follows. Naturally, I consider my contribution to the art to be of considerable breadth, and I shall solicit the grant of patent claims that will prevent the appropriation of my invention by those skilled in the art in forms varying mechanically from the particular form of my invention hereinafter set forth. I
For a detailed description of my invention I shall refer to the drawings wherein Fig. 1 is a general elevation of a truck to which my invention is shown applied.
Fig. 2 is a vertical partial section through the front end of the truck showing the elevating platform lowered.
Fig. 3 is a view of certain parts of Fig. 2 showing the elevating platform partly elevated and with the compound lifting mechanism about to lift the platform at a higher mechanical advan 3 tage than during the first part of the lifting operation from Fig. 2 to Fig. 3.
Fig, 4 is a view of the parts of Figs. 2 and 3 showing the elevating platform fully elevated.
Fig. 5 is a section taken along lines 5-5 of Fig. 2.
Fig. 6 is a section taken along lines 6-45 of Fig.2.
I shall now refer more particularly to the drawings to describe the specific structure of the truck therein shown as embodying my invention. In describing the structure of the truck I shall refer to the parts by the specific names I have chosen for them, ratherthan by generic terms, but those skilled in the art will readily appreciate that the parts of my invention may be varied widely while operating to yield the action that is the contribution of my invention.
Referring first to Fig. l, I show there a single frame truck comprising an elevating platform It and a lifting head designated generally by reference numeral ii, there being several, such reference numerals H applied to the lifting head in order to indicate better its outline. The forward end of the elevating platform. Ill is formed with a vertical standard 12 as is well shown in Figs. 1, 2 and 3, the standard being welded to the elevating platform or otherwise-secured thereto as manufacturing technique may make desirable.
The upper end of the standard l2 is'formed with a pair of brackets l3 supporting a shaft [4 (Figs. 5 and 6), the said shaft l4 formingbearlugs for the inner ends of the upper parallel connecting links l5. The opposite ends of the links I5 are secured-as by welding to a sleeve l6 that is mounted through suitable bushings for rotation about a shaft I! carried in bearings 18 formed on the upper ends of brackets if! that are an integral part of the lifting head II'. In this manner, the elevating platform lll'may be said to be pivoted at-the upper end of its standard l2 relatively to the lifting head I I through the inter mediary of upper parallel links ii.
The lower end of the elevating platform, immediately to the rear of the forward standard [2, is pivoted about the axis of a shaft 2| to opposed links 22 located at each side of the truck. The opposed links 22 are welded to a sleeve 22a (Fig.6) and are thereby pivoted relatively to a shaft 23 mounted on the lower bracket portions 24 of the lifting head as best shown in Figs. 2 and 4. Incldentally, the mechanism whereby links 22 are pivoted about shaft 23 is the mechanism preferably used for linkage mounting throughout the truck.
Through a shaft 25, the links 22 are pivoted to a pair of rods 26 that extend rearwardly to rear wheel supporting links 21 as best shown in Fig. 1. The links 21 carry the rear lifting wheels 28 of the elevating platform land are adapted for rotation about pivot shafts 29. As will be quite apparent, the upward movement of the ele- For holding the elevating platform in its elevated position, once that position is reached, there is utilized a holding strut 39 best shown in Figs. 2, 3 and 4. This strut 30 is pivoted about the shaft M on which the inner ends of the links [5 are mounted, and between the said links, as best shown in Fig. 6. It hangs downwardly from shaft 14 for cooperation witha holding shaft 3| mounted on brackets am, the end of the strut 38 being formed as shown at 33a for this purpose. The holding shaft 3i supports a treadle 32 pinned thereto, and is maintained normally in the position of Fig. 2 by a spring 33 secured at one end to the pin 34 of arm 35 integral with the treadle and shaft-3|, the other end of the spring being secured at 3512 to the lifting head of the truck. Thoseskilled in the art will readily appreciate the action of the holding strut 3B and the holding shaft 3!. The holding mechanism is not part of vating platform relatively to the lifting head about lower links 22 and the upper links is from the position of Fig. 2 to the position of Fig. 4 in a manner to be described hereinafter, effects not only the elevation of the forward end of the elevating platform H], but also the downward movement of the rear wheels 28 to lift the rear end of theelevating platform. The particular construction of the parts so far. described is not per 'se my invention here claimed and is merely set forth to illustrate onetype of truck to whichmy claimed invention may-be applied.
the invention claimed in this application and it istherefore thought unnecessary to describe it in more detail here.
A dashpot 36, best shown in Fig. 6, is utilized to cushion the downward movement of the elevatingplatform when the holding mechanism just described releases it for movement. Since the dashpot and its supporting mechanism is not part of the invention herein claimed, it is not thought necessary to describe it in detail here. As shown in the drawings, the lower end of the dashpot is pivoted about a shaft 38a supported in brackets 31 and 38 formed integrally with the lifting head H. The piston of the dashpot, designated by reference numeral 39, is secured to a block 40 that .is formed with a rounded end 41 as best shown in Fig. 4, for cooperation with a bracket 42 that is an integral part of the standard. 12. For yieldingly maintaining the block 49 and its round end ll against the bracket 52 I utilize the spring bolt arrangement designated generally by reference numeral 43. It is thought that the operation of the dashpot will be quite apparent to those skilled in the art. It may be well at this time to reiterate that the structure so far described is merely' one form of structure that may be employedas part of an industrial truck of the class to Which-may invention may be applied.
Referring now more particularly to Figs. 14 inclusive, the lifting head H of my truck is adapted to support what is termed in theart a steering head. This steering head comprisesv a main casting 45 formed with a sleeve portion; that through the intermediary of a bushing 4'! rotates-relatively to the tubular portion 48 of the lifting head H. The sleeve portion 48 supports the steering wheels in a conventional manner as illustrated. A steering and lifting handle assembly is designated by reference numeral 49, and is supported by a shaft 50, secured to its casting portion 51, for rotation on bearings 5| formed as part of the steering head casting 45. The handle 52 of thesteering and lifting handle assembly 48 is hollow for the housing of a handle balancing mechanism such as is well shown and described in my Patent No. 2,093,392, dated September 14, 1937. The balancing mechanism of the handlecomprises a pair of links 53 pivoted at 54'to the steering head casting 65, the said links 53 supporting about pivot 55 a roller 56, the functioning of which will presently be indicated. It is merely necessary to appreciate at this time that the arrangement of the handle balancingmechanism is such that the handle is yieldingly maintained in its position of Fig. 2 with the'roller 56 also in the position shown inFig. 2.
the lifting member.
The casting 51 of the steering and lifting handle assembly 49, supports a shaft 58 on which is pivoted a link 59. The link 59 in turn has pivoted thereto, through the pin 66, an actuator for In the particular structure shown, the actuator takes the form of a lift hook 6|, the operation of which will be described presently.
The main casting 45 of the steering head carries a bearing shaft 62 on which is adapted to be supported a lifting member designated generally by reference numeral 63. This lifting member 63 is in the form of a bell crank fabricated from a pair of parallel plates 64 pivoted on the shaft 62 and held together by the pins 65 and 66. Pin 65 is termed a lift pin, and cooperates with lift hook 6| as will hereinafter be set forth.
Referring now to Fig. 2, we note there that the elevating platform is in its fully lowered position and that the steering and lifting handle assembly 49 is in its vertical position. With the parts located as in Fig. 2, the roller 56 of the handle balancing mechanism operates against the tail 59a of the link 59 for holding that link in its illustrated position against the force of gravity. It will also be seen that the boss 68 presses downwardly on the thrust roller 61, and that thrust roller 61 in turn presses against the tail 6|a of the lift hook 6|. This action of the bossmoves the lift hook 6| into lifting cooperation with the lift pin 65 extending between the plates 64 of the bell crank lifting member 63. It is therefore seen that when the elevating platform is lowered the parts connecting the lifting handle assembly with the lifting member 63 move automatically toward engagement when the lifting lever is brought into an initial vertical position. This is a very valuable and desirable arrangement because it makes it possible for the operator to begin the lifting operation without performing any intermediate action.
If the operator now desires to lift the elevating platform, he swings the steering handle assembly 49 downwardly toward the positions of Figs. 3 and 4. It is quite obvious that this action serves to rotate the lifting member 63 with its roller 61 applying lifting thrust to the boss 68, and that 6 die assembly 49, the link 59 will function as an integral part of the lifting handle assembly 49 with the result that the rotation of the liftin member 63 will be at a lower rate of speed than during the movementof the parts to the position of Fig. 3.
Continued downward swinging movement of the lifting handle assembly 49 will bring the parts to the position of Fig. 4, in which position the elevating platform is shown fully elevated. As is also seen in Fig. 4, the holding strut is now in holding relation to the shaft 3| so that upward swinging movement of the lifting handle 49 will not be accompanied by a downward movement of the elevating platform [6. Therefore, if the operator now swings the handle assembly 49 upwardly, the lift hook 6| will leave the lift pin 65 and will drop into its dash and dotted line position free of the lifting member 63. This action is entirely automatic and yields what is known in the art as a free handle. It is, of course, obvious that during the lifting operation the stress developed between the hook 6| and lift pin 65 will keep those two parts together.
It may be well to indicate at this point that a lever 15 functions to limit the drop of the lift hook 6| as is apparent in Fig. 4, and also to control the hook. Thus, a treadle 16 is secured to a shaft 11 fixed to the lever 15. the shaft 11 being supported as best seen in Fig. 5 by suitable bearings 18 on the steering head. With this arrangement of the parts, depression of the treadle 16 will bring the lift hook 6| in engagement with the pin 65 should such engagement be desired as where special control of the lifting member 63 is necessary. The treadle i6 and lever 15 may also be useful where an intermediate lift is desired, in which case the strut 36 will be made to hold the elevating platform in more than one elevated position. Because this structure is not claimed in this application no further showing v thereof is thought necessary here.
Should the operator step on the treadle 32 to effect the lowering of the elevating platform, he will move the holding strut 30 out of holding position and the elevating platform will be lowered toward the position of Fig. 2 under the control of the dashpot assembly 36. The parts will 'of course gradually move into the position of Fig. 2 and the boss 68 will effect the movement of the lift hook 6| toward the lift pin 65 so that a second lifting operation may be performed. without any additional intermediate acts.
The operation and construction of my invention will now be quite clear to those skilled in the art.
I now claim:
1. In a lifting truck, a lifting head, an elevating platform, means mounting said elevating platform for lifting movement relatively to said lifting head, a lifting member for lifting said elevating platform movably mounted on said lifting head, a part of said elevating platform extending over said lifting member for engagement thereby in all positions of said elevating platform,
a steering and lifting handle pivoted on said lifting head for vertical swinging movement, a link pivoted on said steering and lifting handle, means pivoted on said link adapted to engage and disengage said lifting member, and movable upon downward swinging of said steering and lfting handle when engaged with said lifting member for moving said lifting member to contact the part of said elevating platform to lift said eleve ing platform.
. 9 of said lifting member in all positions of said elevating platform, a steering and lifting handle pivotally mounted on said lifting head,'connectof engagement with said lifting member but held in engagement by the lifting stress therebetween during lifting movement of the steering and lift- 3 ing handle, the relieving of said stress as after the elevation of said platform allowing separation of said connecting means, from said lifting member to contribute a free steering and lifting handle, and means whereby said connecting means are moved toward engagement with said lifting member by the lowering movement of said elevating platform.
10. In a truck of the class described, a lifting head, an elevating platform, means mounting said elevating platform for lifting movement relatively to said lifting head, a steering head rotatable on said lifting head, a bell crank pivoted on said steering head and having a thrust imparting portion thereon, a boss secured as a part of said elevating platform and overlying said thrust imparting portion in all steering positions of said steering head and in all positions of said elevating platform, a steering and lifting handle pivoted on said steering head for downward swinging movement, a link pivoted on said steering handle, a hook pivoted to said link and adapted to engage a part of said bell crank to rotate said bell crank when the steering and lifting handle swings downwardly, whereby through said thrust imparting portion and boss to lift the elevating platform, said hook being biased normally out of engagement with said part but adapted to be held in engagement therewith by the stress therebetween incidental to the lifting operation, the relieving of said stress as after the elevation of said platform allowing separation of said hook from said bell crank part to contribute a free steering and lifting handle.
11. In a truck of the class described, a lifting head, an elevating platform, means mounting said elevating platform for lifting movement relatively to said lifting head, a steering head rotatable on said lifting head, a bell crank pivoted on said steering head and having a thrust imparting i portion thereon, a boss secured as a part of said elevating platform and overlying said thrust imparting portion in all steering positions of said steering head and in all positions of said elevating platform, a steering and lifting handle pivoted on said steering head for downward swinging move- 'ment, a link pivoted on said steering handle, a
hook pivoted to said link and adapted to engage a part of said bell crank to rotate said bell crank when the steering and lifting handle swings downwardly, whereby through said thrust imparting portion and boss to .lift the elevating platform, said hook being biased normally out of engagement with said part but adapted to be held in engagement therewith by the stress therebetween incidental to the lifting operation, the relieving of said stress as after the elevation of said platform allowing separation of said hook from said bell crank part to contribute a free steering and lifting handle, and means whereby said hook is moved toward engagement with said bell crank part when said elevating platform is lowered.
12. In a truck of the class described, a lifting head, an elevating platform, means mounting said elevating platform for lifting movement relatively to said lifting head, a steering head rotatable on said lifting head, a bell crank pivoted on said steering head and having a thrust imparting portion thereon, a boss secured as'a part of said elevating platform and overlying said thrust imparting portion in all steering positions of said steering head and in all positions of said elevating platform, a steering and lifting handle pivoted on said steering head for downward swinging movement, a link pivoted on said steering handle, a hook pivoted to said link and adapted to engage a part of said bell crank to rotate said bell crank when the steering and lifting handle swings downwardly, whereby through said thrust imparting portion and boss to lift the elevating platform, said hook being biased normally out of engagement with said part but adapted to be held in engagement therewith by the stress therebetween incidental to the lifting operation, the relieving of said stress as after the elevation of said platform allowing separation of said hook said lifting head, a bell crank pivoted on said steering head and having a thrust imparting portion thereon, a boss secured as a part of said elevating platform and overlying said thrust impart ing portion in all steering positions of said steering head and in all positions of said elevating platform, a steering and lifting handle pivoted on said steering head for downward swinging movement, a link pivoted on said steering handle, a hook pivoted to said link and adapted to engage a part' of said bell crank to rotate said bell crank when the steering and lifting handle swings downwardly, whereby through said thrust imparting portion and boss to lift the elevating platform, said hook being biased normally out of engagement with said part but adapted to be held in engagement therewith by the stress therebetween incidental to the lifting operation, the relieving of said stress as after the elevation of said platform allowing separation of said hook from said bell crank part to contribute a free steering and lifting handle, and means whereby when said handle is in its vertical position when the platform is lowered said boss moves said bell crank part and hook into engagement.
14. In a truck of the class described, a lifting head, an elevating platform, means mounting said elevating platform for lifting movement relatively to'said lifting head, a steering head rotatable on said lifting head, a bell crank pivoted on said steering head and having a thrust imparting portion thereon, a boss secured as a part of said elevating platform and overlying said thrust imparting portion in all steering positions of said steering head'and in all positions of said elevating platform, a steering and lifting handle piv oted on said steering head for downward swinging movement, a link pivoted on said steering handle, a hook pivoted to said link and adapted to engage a part of said bell crank to rotate said bell crank when the steering and lifting handle swings downwardly, whereby through said thrust imparting portion and boss to lift the elevating platform, said hook being biased normally out "of engagement with saidpartbut adapted to be held in engagement therewith by the stress therebetween incidental to the lifting operation,- the relieving of said stress as after the elevation of said platform allowing separation of saidhookfromi-said" bell crank part to. 'contrlbutea free steering and lifting handle, and means whereby said hook is moved into engagement with said bell crank part when said elevating platform is "low-- ered' and said steering and lifting handle i inlan initial vertical position.
15.: In a truck-of the classcdescribed, a-lifting head,zan elevating platform; means mounting said elevating platform for lifting movement relatively to said lifting head, a steering'head rotatable on said lifting head, a bell crank pivotedon said steering head and having athrust imparting portion thereon, aboss secured as a part of said elevating platformand overlying said thrust im'- parting ortion in all steeringpositions of said steering head and in all positionsof said elevating platform, a steering and liftinghandle pivoted on 25 saidsteering head for downward swinging movement, a link pivoted on said steering handle, .a hook pivoted tosaidlink and adapted to engage a part of said bell crank to rotate said bell crank-- when the steering and lifting, handle swings 3Q downwardly, whereby; through said thrust imparting portion and boss to lift the elevatin D1atform, said hook being biased normally out engagement with said part but adapted to behold in: engagement therewith bythe "stress therebe tween incidental to the lifting operation, the2relieving of said stress as after the elevation of said platform allowing separation of said hook from said bellcrank part to oontributeafreesteering and lifting handle, and means wherebysaid link and hook are positioned automatically to effect engagement of said hook with said bell crank part when saidelevating platform is in its lowered position and said steering and lifting handle 'is in an initial vertical posit-ion.
16; In a truck of the class described, a lifting head, an elevatingplatform, means mounting,
said elevating platform for lifting movement relatively to said lifting head, a steering head rotatable on said lifting head, a bell'crank pivoted on said steering head and having a thrust im-- parting. portion thereon, a boss secured as. a part of =saidelevatingmlatform and overlying said thrust imparting portion in allv steering positions of said steering head and in; all positions :of said elevating platform, a steering and lifting handle pivoted on said steering head; for-downward swinging movement, a. hook movable with said steering and lifting handle: and adapted to en, gage: a part of said bell crank to rotate saidbell crank when the steering and lifting handle swings downwardly; whereby through said thrustimparn, ing portion and boss to lift the elevating platform, saidlhook Qing'biaSed norm lly o t. of-eng e ment. h anger: but; adapt diobe held: in en.
gagement therewith by the .stress .thEIQbEtWeBL incidental to the lifting operatiomthe relieving of said stress as after the: elevation of saidplatform allowingseparation ofsaid hook-from said bell."
crank part tocontribute a free steering and lift lnghandle, and means whereby said hook, is positionedfautomatically to effect, engagement of said hook with said bell crank partby the lowering movement of said elevating'platform.
17'. In a truck of the class'described, a lifting head, an elevating platform, means mounting said elevating platform for lifting movement relatively to said liftinghead, a steeringhead rotatable'on said lifting head, a bell crank pivoted on said steering head'and having a thrust impartlo'ing portion thereon, a-boss secured as a part of said elevating platform and overlying said thrust impartingportion in all steering positions of said steering head and in all positions of said elevat ing platform, a'steering and lifting handle pivoted on said steering head for downward swinging movement, a hook movable with said steering and lifting handle and adapted to engage a part of said bell crank to rotate said bell crank when the steeringand lifting handle swings downwardly, whereby through said thrust imparting 18. In .a truck of the class described, a lifting need, an elevating p1atform,means mounting said 1 ;,elevating platform for lifting movement relatively to said lifting head, a. steering head rotatable on said lifting head, ,a bell crank pivoted on said steering head and having a thrust imparting portion thereon, a boss secured as a part of said ele- 40 vating platform and overlying said thrust imparting portion in all steering positions of said steering head and in all positions of said elevating platform, a steering and lifting handle pivoted on saidsteeringhead for downward swinging move- 4o ment, a link pivoted'relatively to said steering handle and adapted to engage a part of said bell crank to rotate said bell crank when the steering and lifting handle swings downwardly, whereby through said thrust imparting portion and boss to liftthe elevating platform, said link being biased normally out of engagement with said part but 'adaptedto be held in engagement therewith by the stress therebetween incidental to the liftingoperation, therelieving of said stress as after the elevation of said platform allowing separation of said link from said bell crank part to contribute a free steering .andlifting handle, and means whereby said link is moved toward engagement with saidbell' crankpart by the lowering movement ofsaid elevating platform.
GEORGE QUAYLE'.
REFERENCES. CITED. The-following references are'of record in the file of thls'patent:
STATES PATENTS.
Number- Name Date 1,741,712 Hennessy Dec. 31, 1929 70. 1,769,995 Hennessy July 8, 1930 1,773,935 Barrett Aug. 26, 1930
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US520186A US2439781A (en) | 1944-01-29 | 1944-01-29 | Hand lift truck |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US520186A US2439781A (en) | 1944-01-29 | 1944-01-29 | Hand lift truck |
Publications (1)
Publication Number | Publication Date |
---|---|
US2439781A true US2439781A (en) | 1948-04-13 |
Family
ID=24071518
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US520186A Expired - Lifetime US2439781A (en) | 1944-01-29 | 1944-01-29 | Hand lift truck |
Country Status (1)
Country | Link |
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US (1) | US2439781A (en) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1741712A (en) * | 1928-02-03 | 1929-12-31 | Lewisshepard Company | Elevating truck |
US1769995A (en) * | 1929-07-23 | 1930-07-08 | Shepard Co Lewis | Elevating truck |
US1773935A (en) * | 1927-07-21 | 1930-08-26 | Barrett Cravens Co | Lift truck |
-
1944
- 1944-01-29 US US520186A patent/US2439781A/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1773935A (en) * | 1927-07-21 | 1930-08-26 | Barrett Cravens Co | Lift truck |
US1741712A (en) * | 1928-02-03 | 1929-12-31 | Lewisshepard Company | Elevating truck |
US1769995A (en) * | 1929-07-23 | 1930-07-08 | Shepard Co Lewis | Elevating truck |
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