CA1050583A - Two-wheel hand truck with elevator - Google Patents
Two-wheel hand truck with elevatorInfo
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- CA1050583A CA1050583A CA231,748A CA231748A CA1050583A CA 1050583 A CA1050583 A CA 1050583A CA 231748 A CA231748 A CA 231748A CA 1050583 A CA1050583 A CA 1050583A
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Abstract
Inventor: Bruce A. Walker Title: TWO WHEEL HAND TRUCK WITH ELEVATOR
ABSTRACT OF THE DISCLOSURE
An elevating mechanism is incorporated into the body of a two-wheel hand truck. The upright rails of the hand truck are tubular, slotted and open at their bottom ends. An elevator leg is telescopically mounted in each rail, and the two elevator legs are interconnected by a ladder-like array of cross bars extend-ing from the slots in the truck rails. Accordingly, the elevator legs will move in unison, and a crank-operated chain-pull mecha-nism at the back side of the truck is attached to an elevator-leg-cross bar to forcibly extend the elevator downwardly. An auto-matic safety brake on the crank will prevent dropping of the load should the crank be accidentally release, and a hand operated brake will bock the wheels of the hand truck when desired.
ABSTRACT OF THE DISCLOSURE
An elevating mechanism is incorporated into the body of a two-wheel hand truck. The upright rails of the hand truck are tubular, slotted and open at their bottom ends. An elevator leg is telescopically mounted in each rail, and the two elevator legs are interconnected by a ladder-like array of cross bars extend-ing from the slots in the truck rails. Accordingly, the elevator legs will move in unison, and a crank-operated chain-pull mecha-nism at the back side of the truck is attached to an elevator-leg-cross bar to forcibly extend the elevator downwardly. An auto-matic safety brake on the crank will prevent dropping of the load should the crank be accidentally release, and a hand operated brake will bock the wheels of the hand truck when desired.
Description
The present invention relates to two-wheel hand trucks and more particularly to means and apparatus to facilitate the raising and lowering of a loaded two-wheel hand truck from one level to anotherO
In the present invention, the raising and lowering ap-paratus is incorporated into the hand truck itself and thus, a primary object of the invention is to provide, in a two-wheel hand truck, a novel and improved elevating mechanism capable of raising and lowering a two-wheel hand truck from one level to another. As such, the invention will be hereinafter calied a "t~o~
; wheel hand truck with elevator" and the elevator will also be referred to as an "elevating mechanism".
Another object of the invention is to provide a novel and improved two-whèel hand truck having an elevating mechanism which is adapted to raise and lower the hand truck from one level ko another, not only for short distances such as up and down a stair, but also in situations where the vertical distance is sub-stantial, ~uch as, for example, from lhe ground level to the cleck of a van or to a loading dock, severa]L feet above the ground.
Another object of the invenlion is to provide a two-wheel hand truck which carries a novel and improved elevating mechanism within it which is capable of raising and lowering t:he hanrd truck, when loaded, from one leveI to another by simple, easy, manual operations without the need of the operator strain-ing or overly exerting himself.
Another object of the invention is to provide a novel and improved ~levating mechanism which is incorporated into a hand truck in a simple, structurally-sound, reliable and effec-tive manner, which does not impair or significantly alter the balance of the hand truck while an operator is handling and elevat~
ing it, and which can easily accommodate conventional safety fea tures to minimize the chances of the hand truck getting out of , . : . -:
: ' ' control.
The invention may be generally defined as a two-wheel hand truck having an elevator mechanism to facilitate raising and lowering the hand ~ruck to and from an elevated deck and comprising a hand truck, the basic . .
structure of which includes a pair of longitudinally extended tubular rails open at their bottom ends, a transverse pickup lip outstanding from the bottom front edge of the rails, a pair of spaced wheels mounted upon a transversely disposed wheel shaft adjacent to the bottom back edge of the rails and a handle at the top of the rails, all in an arrangement which permits a load to be picked up by the lip and lie against the front side of the rails when the truck is tipped rearwardly onto the wheels. The elevator mechanism includes a leg telescopically carried in each rail with the length of the leg approaching the length of ~he rail. An extension means is provided to extend and to retract a substantial portion of the legs from the bottom of the rails in unison to raise and lower the truck with a load thereon to a height which is a substantial portion of the height of the hand truck. Finally a cranking means is provided to operate the extension means.
With the foregoing and other objects in view, my present invention comprises certain constructions, combinations and arrangements of parts and elements as hereinafter described, defined in the appended claims and illustrated in preferred embodiment by the accompanying drawings in which:
- Fig. 1 is an isometric view of a two-wheel hand truck constructed according to the present invention by incorporating an elevator within its frame, the elevator illustrated as being partially extended to lift the -~
hand truck upwardly against the tailgate of a pickup truck to ultimately ' place the hand truck onto the deck oE the pickup truck;
Fig. 2 is a front elevation view of the two-wheel hand truck with the elevator retracted and with strap portions of the hand truck being broken away to show parts behind the straps;
Pig. 3 is a right-side elevation view of the hand truck with a portion of a side wheel being broken away to show the frame structure behind the wheel;
, Fig. 4 is a sectional side elevation view as taken from the indicated line 4-4 at Fig. 2;
Fig. 5 is a sectional side elevation view as taken from the indicated line 5-5 at Fig. 2;
Fig. 6 is a fragmentary sectional detail to show the upper portion of the elevating mechanism as taken from the indicated line 6-6 at Fig. 2, but on an enlarged scale;
Fig. 7 is a sectional detail as taken from the indicated line 7-7 at F g. 2, b~t with the leg of the elevating mechanism ',',f,'~ 3a -:' ' '', ; ,, ' ~' ' , , ~ , ,: ; , :
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being extended downwardly the same as illustrated at Fig. l;
Fig. 8 is a plan view of the hand truck as from the in-dicated arrow at Fig. 3, but on an enlarged scale;
Fig. 9 is a sectional plan view as taken from th~ indi-cated line 9-9 at Fig. 2, but on an enlarged scale;
Fig. 10 is a fragmentary sectional detail as taken from the indicated line 10-10 at Fig. 3, but on an enlarged scale;
Fig. 11 is a side elevational view of a hand truck simi-lar to Fig. 3, but showing the hand truck as being tilted against the deck of a truck with a modified arrangement for supporting the back of the truck against the corner of the deck;
Fig. 12 is a fragmentary detail view of a leg per se .
used in the truG~ shown at Fig. 11 to further illustrate the sup-porting member;
Fig. 13 is a fragment of the back side of the leg shown at Fig. 12 to illustrate further the manner of connecting the support to the leg; and Fig. 14 is a sectional view as taken from the indicated line 14-14 at Fig. 12, but on an enlarged scale.
The common two-wheel hand truck is used extensively to handle heavy, rigid, box-like loads, especially on a one man job.
The body of such a truck consists of a pair of upright rails which are spaced apart by crossbars and these rails are tipped to hold a load at their front faces. A lip outstands from the bottom edge o the front faces of the rails to reach underneath a load to pick it up and to place it upon the rails when the truck is tipped.
Two spaced-apart wheels are mounted upon a shaft at the back side of the rails and at the bottom of the truck so that when the ~ruck is tilted, it will be upon these wheels. Finally, a handle is provided at the top of, and at the back side of, each rail to enable an operator to hold the truck. In picking up a load, the operator pushes the truck against the side of a box-like load and :, . . . . :
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pushes the lip underneath it. He then tips the truck and the load rearwardly to place the load upon the truck. So posi-tioned, an operator can balance the load over the wheels and easi-ly move the loaded truck to its destination~
Such hand trucks are useful for moving loads across level, smooth surfaces, but they are awkward to handle when they must be lifted or lowered, such as up and down a stairway, and even more so where the lift is a substantial distance such as from the ground surface to a truck bed or from a ground surface to a loading dock. In many instances, ramps are provided where such lifting pxoblems exist, but pulling a loaded hand truck up a ramp is hard muscle-straining work, while guiding a truck down a ramp involves the risk of the l~ad getting away from the operator.
It follows that there is a need for an improved system for handling heavy loads with hand trucks where they must be Li~t-ed or lowered vertical distances as to and from truck beds and loading docks. The present invention was conceived and developed with the above considerations in view and comprises, in essen~e, a two-wheel hand truck having a pair of downwardly extendible legs forming part of an eleva~ing mechanism for raising and lower-ing the hand truck. In the preferred embodiment, the elevating legs are within hollow, slotted rails to telescopically extend therefrom. The rail slots permit the legs to be tied together to assure their movement in unison. The truck structure is aLso modified to an arrangement which permits the legs to be extended below the truck without interfering with the regular structural components o~ the truck. The legs are forcibly e~tended by a suitable, simple, chain-pull mechanism which is operated by a crank located on the hanclle at the top of the truck. Safety brake features may be included in this organization to prevent the crank from getting away from an opera-tor and also hold the truck wheels.
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Referring more particularly to the drawing, Figs. 1 to 10 depict a preferred embodiment of the invention, a two-whee:L
hand ~ruck T. This hand truck is essentially conventional in its general form and can be used the same as a standard hand truc]c.
The body of the truck T includes a pair of longitudinal upright rails 20 which are held apart in spaced parallelism. These rails are slotted, tubular members and the bottoms are open to carry extension legs E as hereinafter described. The other regular components of the truck are mounted upon the rails in an arrange-ment which will not inter~ere with the movements of these exten-sion legs.
A transverse pickup lip 21 outstands from the front face of the body at ~he bottom of the rails to lift a load which is to be tilted against the front of the body when the truck is be-ing used in a conventional manner. Left and right side wheels 22 are mounted upon a transverse shaft 23 behind the rearward faces of the rails 20 and near the bottom of these rails, with a wheel being at each outer side of each rail. The shaft 23 is held in position by bearing clips 24, and a clip 24 is affixed to the outward side of each rail 2~ with the shaft 23 projecting thererom to carry the wheeIs 22, as best shown at Fig. 3.
The two parallel rails 20 are held apart and in position at the bottom of the truck by ~ face plate 25 weIded or otherwise fastened to the front faces of the rails. Preferably, the face plate 25 is formed by folding the rearward portion of the lip 21 upwardly to lie against the front face of the rails. These rails are also held apart and in position at the top of the truck by a transverse structural pipe or tube 26 extending between and being securely welded to the rails. Other intermediate structural com-ponents may also be included to hold these rails in position pro-viding they are at the front or rear faces of the rails and in a position which will not interfere with the movement of the exten-:-- 6 --.
~ s~
sion legs as hereinafter described. In addition, a number of pli-able straps 27 may be spaced between the rails at the outer face thereof to hold a load thereon.
To complete the conventional arrangement, a transverse, tubular handle 28 is carried at the rear end of bars 29 projec-ting rearwardly from the top of each rail. In the present inven-tion, ~he handle 28 is modified to carry a transverse crankshaft, as hereinafter described.
This essentially conventional arrangement of a two-wheeL hand truck, as above described~ is modified to carry an ex-tension mechanism E by using tubular or hollow rails 20 as hereto-fore mentioned. These rails are rectangular in cross~section and have elsngated slots 30 at the~inner face of each rail which ex-tend the entire length of the rails. So positioned, the slots ; 30 in the rails oppose each other. Structural steel hollow sec-tions suitable for the purpose are commonly available in various standard sizes. For example, a suitabIe size for the purpose is a 2 x 4-inch hollow rectangular tube of 14 or 16 gage thickness h~v~ng a 2-inch slot at one~face, the slot 30 at the inner face of each rail 20.
The extension mechanism E includes a pair of legs 31 and a leg 31 is slidably fitted into each xail 20 to project from the bottom of the truck body. The legs 31 are interconnected by rung-like cross bars 32 in a ladder-like arrangement at;any seLected spacing, and although two cross bars 32 are shown, any number of cross bars, and even diagonal brace bars, may be select-ed for the purpose. Thé cross bars 32 extend from the opposing xail slots 30 between the rails and thus the legs may freely slide into and out of the rails 20 without *he cross bars 32 interfering with the structure of the truck T.
Since the truck will be lifted upon and supported by these legs 31, as illustrated at Fig. 1 and hereafter further . .: :" ' . . .
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~5~35~3 described, the base of each ley 31 is desirably fitted with an anti-slip shoe 33, a U-shaped member having an anti-slip under-surface, having its side portions connected to the base of each leg by a pivot 34 so that the shoe can be tipped to adjust to any tilt of the hand truck, or irregularity of the ground sur-face.
It is desirable to have the legs 30 to move in the rails with a free, easy sliding action. Accordingly, the legs 31 are rectangular in cross section, similar in form to the rails 20 but smaller so that they may telescope into the rails with a free-sliding fit. To minimize frictional resistance to movement of the legs within the rail, the top of each leg 31 is formed as I a clQvis-like crotch to hold a roller 35 upon a short shaft 36 ~'~ between the arms of the crotch.' The roller 35 will bear against ;~ the front face or rear face of the railæ, inside the rails, to keep the top portion of the legs from dragging. To minimize the~frictional resistance of a leg 30 bearing against the base of each rail 20, an anti-friction slide plate 37 is located at the front side of the base of the rail passageway and a rollex 38 is carried upon the whéel shaft 23 to project through an open-ing 33 in the back side of the rail 20, the'slide 37 and roller 38 being best sho'w~at Figs. 4 and 9.
The extension legs 3I are forcibly extended downwardly from the body o the truck and upwardly into the truck by turll-ing a crank 40 mounted upon a transverse shaft 41 which extends ~'~
through the transverse, tubular handle 28. ~he handle 28 is locat~d approximately 9 inches or so behind the rails, and is supported by the shbrt flat bars 29, as heretofore described.
For a right-hand operator, the crank'40 is located at the out-- -ward æide of thé right-hand bar 29. The shaft 41 transmits torque to a drive sprocket 42 mounted on the'shàft 41 at the center of the handle 28. The handle 28 is divided into two . ~ , . . ~ . . . : " , . .
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ii615~3 sections to allow for this sprocket. The sprocket 42 and other mechanisms ar~ housed in a simple gearcase 43 in thP form of a plate, folded to an inverted U and mounted at the center of the truck between the handle 28 and the spacer rod 26. The drive sprocket 42 is connected by a chain 44 to a torque-increasing sprocket 45 carried upon a shaft 46 within the gearcase 43, as shown at Fig. 6. The shaft 46 also carries a driven sprocket 47, connected with the torque-increasing sprocket to rotate therewith, and a lift chain 48, extending to ~he base of the truck is car-ried on the driven sprocket 47.
The lift chain 48 extends downwardly between the rails,at tha back side of the truck and to the bottom of the truck to an idler sprocket 50 mounted upon the'wheel shaft 230 The lift chain 48 thus forms a loop about the drive sprocket 47 and the idler spxocket 50. A clip 51 at the forward reach of this chain loop connects with'a sel:ected cross bar 32 which interconnects the:extension legs 3I. Accordingly, the'rotation of the crank 40 I turns the several sprockets wi:thin the gearcase 43'to operate the I lift:chain, which,' in turn, will extend or retract the elevator E to raise and lower the truck T to,various positions such as il- :
lustrated at Fig. 1. When lifting the truck, the entîre pull of the :chain will be upon the idler sprocket 50, and upon the wheel : ' !
shaft 23. To facilitate supporting this shaft 23,' the shaft :is carried in tubular support sections 52, as illustrated at Fig. 9, ' .
and these sections are supported by struts,53, as best illustrat~
ed at Figs. 2,,7 and 8. The movement of the extension legs from the rails 20 is 1imited by the location of the clip 51 or chaln 48 with~respect to the legs 31 since this clip cannot move down~
wardly beyond thé sprocket 50 about which the chain 48 turns.
ThIs clip is necessarily located a short distance from the top of the legs 31 below the roller 35, as upon a crossbar 32, as best:illustrated at Fig. 5. This permits the upper portion of :::
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ea~h leg 31 to remain within the embrace of the rails 20 when the leys are, operatively, fully extended. Such prevents a buck-ling of the leg~ at the bottom of the rails such as would occur if the top of the legs were at the bottom of the rails. This lo-~ cation of the clip 51 with respec't to the top end of the legs 31 ; thus provides a structure which will not be overstressed when the legs are, operatively, fully extended. A properly proportioned arrangement, such as that illustrated, can be easily determined by any skilled designer.
A crank brake 54 of a standard type which is normally locked and which will reIease only when the crank 40 is turned, is mounted upon the outer face of the handle support bar 29 adja-cent to the'crank 40. This brake prevents~the truck from acci-clentally,,suddenly dropping if an operator accidentally releases the handle 40 and is an important safety ~eature. This brake may be a conventional type, such as the hand brake manufactured by the Fulton Mfg. Co. of Milwaukee,,Wisconsin, cataloged as , No. 560 hand brake and hence it need not be described.
In addition to the automatic crank-brake 54 to prevent the truck from dropping when it is loaded, a hand brake 55 is pro-vided for preventing rotation of the wheels 22. This hand brake is conveniently located at ,the'left side of the truck in associ- ;, ation with the handle 28 so that an operator may apply the brake 55 wi,th his left hand while cranking with his right hand. The hand brake,55 is formed as a gripper bar adapted to lie along-~ side the handle 28 and to be pulled thereagainst. As such, it '~ is carried upon a lever arm 56 pivotally connected to the left side bar 29 as best illustrated at Fig. 7. The lever, in turn, is connected with a pair of braking cables 57 and 58 which are housed in cable sheaths 59 and 60~ respectively. The cable ,, sheaths 59 and 60 extend from the bifurcation point of the cables to the'interior of the support tube 26 to divert to the left and , 58~
right hand sides of the truck, as best illustrated at Fig. 8.
The sheaths then extend from their respective ends of the tube and through the walls of the rails 20 to lie alongside the outer - face o~ the respective rails to extend downwardly alongside the rails and to terminate at a point near the wheel 22 at the base ; of the truck. Each brake cable 57 and 58 extends from its shea~h and connects with a lever arm 61 adjacent to the wheel 22. I'his lever arm includes an outstanding tab 62 to engage the wheel.
Each lever 61 is pivotally connected to the rail in a position to move the pad 62 against the wheeI whenever its cable 59 or 60 is ' pulled upwardly. A spring 63 opposing the cable tends to normal-ly pull the pad away from the wheel. It follows that whenever an operator squeezes the brake handle, both'of the cabIes will be ~' pulled to lock both wheelc.
It is a relatively simple~ matter to lift a loaded two-wheeI hand truck with the elevator E ~he eIevator is normally kept at a retracted position and a load is placed' upon the hand truck in a conventional manner. The hand truck is then tipped to ride upon the wheels 22 on a level' surface'to ihe' rear of a vehicle or to the edge of a dock whereon it is to be lifted. The hand truck is then moved to rest in a tipped position against the edge'of the vehïcle'or dock as illustrated at Fig. 1. Next, the operator will get upon the d~ck of the vehicle'or dock to hold the hand truck in place'and he commences to turn the crank 40 with ;~ his right hand to cause thé elevator legs to be'extended downward-ly, lifting the truck and its load. By continuing this cranking operation, the hand truck is raised to a poink where'the wheels 22 ride over the edge o~ the vehicle tailgate or dock. The hand brake 55 locks the whéels 22 to prevent the truck from getting away ~rom the operator, and the elevator legs may then be re-tracted to permit the hand truck to continue its trip on the vehicle or dock to bring the load to its destination.
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,, , '' , An operation to lower a load from a vehicle or a dock to the ground surface is easily accomplished in substantially the same manner, but wi-th the steps being in the opposite sequence.
; The hand truck is rolled to the edge of the dock, the hand brake 55 is applied to prevent the loss of the load. Next, the legs 30 are extended downwardly to engage the lower surface and to then lift the vehicle and its load from the dock or truck deck.
Subsequently, the truck is lowered downwardly to the base eleva-tion of the vehicle deck or dock.
In order to slide the hand truck smoothIy against the edge of a vehicle dock or tailgate and to ease the wheels 22 over this edge, a slide bar 65 i5 secured to the~rearward side of each rail to engage the edge of the dock or tailgate. The slide bar extends from a point near the top of the hand truck to a position adjacent to the wheeIs 22 as illustrated and it is spaced reax-wardly ~rom the rearward edge of the rail to provide clearancl_ for the lift chain 48 and to provide a smooth transition from the ~ -~, slide bar to the wheels 22 as they move upon the deck of a vehicle i or dock. A slide bobbin 66 may be mounted upon each slide bar 65 to be held against the edge of a vehicle tailgate or loading dock deck, as illustrated at Fig. 1. This bobbin may be a simple, plastic member, as illustrated at Fig. 10, and it may be propor-tioned to slide freeIy upon its bar 65. A small frictional drag may be provided by a clip 67 so that the bobbin can be placed at i any select~d position upon the slide barO It is also contemplat-ed that the slide bar 65 will be of fairly hard material and ~will freely slide along the edge of a truck deck or loading dock i~
the bobbin is not used.
Other arrangements for easing the sliding action of the back edge of the rails 20 against the edge of a tailgate or dock are also pQs~ible, such as slide pads at the edge of the tailgate or dock or a pulley-belt arrangement at the back of the rails.
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Such arrangements are not shown since they are entirely conven-tional.
An alternative arrangement for holding the rear edge of the hand truck away from the corner of a vehicle deck or load-ing dock deck is illustrated at Figs. 11, 12 and 13 where a fend-er 70 is provided on each leg 31' to contact the corner of the deck. This finder 70 is formed as a looped arm which extends be-hind the rear edge of the hand truck and extends downwardly from the arm in spaced parallelism with the leg 32'. The spacing of each fender 70 from the truck rails is at a distance sufficient to straddle the shaft 23 and roller 38 upon this shaft to permit the wheels 22 to move past the fender arms and onto the deck in - a manner ess~ntially the same as heretofore~described.
I have n~w described my invention in considerable detail.
However, it is obvious that others skilled in the art can build and devise alternate and equivalent cs~nstructions which are never-theIess within the spirit and scope oiE my invention. Hence, I
desire that my pro-tection be limited not by the constructions il-lustrated and described, but only by the proper scope of the ap-20 pended claims.
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In the present invention, the raising and lowering ap-paratus is incorporated into the hand truck itself and thus, a primary object of the invention is to provide, in a two-wheel hand truck, a novel and improved elevating mechanism capable of raising and lowering a two-wheel hand truck from one level to another. As such, the invention will be hereinafter calied a "t~o~
; wheel hand truck with elevator" and the elevator will also be referred to as an "elevating mechanism".
Another object of the invention is to provide a novel and improved two-whèel hand truck having an elevating mechanism which is adapted to raise and lower the hand truck from one level ko another, not only for short distances such as up and down a stair, but also in situations where the vertical distance is sub-stantial, ~uch as, for example, from lhe ground level to the cleck of a van or to a loading dock, severa]L feet above the ground.
Another object of the invenlion is to provide a two-wheel hand truck which carries a novel and improved elevating mechanism within it which is capable of raising and lowering t:he hanrd truck, when loaded, from one leveI to another by simple, easy, manual operations without the need of the operator strain-ing or overly exerting himself.
Another object of the invention is to provide a novel and improved ~levating mechanism which is incorporated into a hand truck in a simple, structurally-sound, reliable and effec-tive manner, which does not impair or significantly alter the balance of the hand truck while an operator is handling and elevat~
ing it, and which can easily accommodate conventional safety fea tures to minimize the chances of the hand truck getting out of , . : . -:
: ' ' control.
The invention may be generally defined as a two-wheel hand truck having an elevator mechanism to facilitate raising and lowering the hand ~ruck to and from an elevated deck and comprising a hand truck, the basic . .
structure of which includes a pair of longitudinally extended tubular rails open at their bottom ends, a transverse pickup lip outstanding from the bottom front edge of the rails, a pair of spaced wheels mounted upon a transversely disposed wheel shaft adjacent to the bottom back edge of the rails and a handle at the top of the rails, all in an arrangement which permits a load to be picked up by the lip and lie against the front side of the rails when the truck is tipped rearwardly onto the wheels. The elevator mechanism includes a leg telescopically carried in each rail with the length of the leg approaching the length of ~he rail. An extension means is provided to extend and to retract a substantial portion of the legs from the bottom of the rails in unison to raise and lower the truck with a load thereon to a height which is a substantial portion of the height of the hand truck. Finally a cranking means is provided to operate the extension means.
With the foregoing and other objects in view, my present invention comprises certain constructions, combinations and arrangements of parts and elements as hereinafter described, defined in the appended claims and illustrated in preferred embodiment by the accompanying drawings in which:
- Fig. 1 is an isometric view of a two-wheel hand truck constructed according to the present invention by incorporating an elevator within its frame, the elevator illustrated as being partially extended to lift the -~
hand truck upwardly against the tailgate of a pickup truck to ultimately ' place the hand truck onto the deck oE the pickup truck;
Fig. 2 is a front elevation view of the two-wheel hand truck with the elevator retracted and with strap portions of the hand truck being broken away to show parts behind the straps;
Pig. 3 is a right-side elevation view of the hand truck with a portion of a side wheel being broken away to show the frame structure behind the wheel;
, Fig. 4 is a sectional side elevation view as taken from the indicated line 4-4 at Fig. 2;
Fig. 5 is a sectional side elevation view as taken from the indicated line 5-5 at Fig. 2;
Fig. 6 is a fragmentary sectional detail to show the upper portion of the elevating mechanism as taken from the indicated line 6-6 at Fig. 2, but on an enlarged scale;
Fig. 7 is a sectional detail as taken from the indicated line 7-7 at F g. 2, b~t with the leg of the elevating mechanism ',',f,'~ 3a -:' ' '', ; ,, ' ~' ' , , ~ , ,: ; , :
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being extended downwardly the same as illustrated at Fig. l;
Fig. 8 is a plan view of the hand truck as from the in-dicated arrow at Fig. 3, but on an enlarged scale;
Fig. 9 is a sectional plan view as taken from th~ indi-cated line 9-9 at Fig. 2, but on an enlarged scale;
Fig. 10 is a fragmentary sectional detail as taken from the indicated line 10-10 at Fig. 3, but on an enlarged scale;
Fig. 11 is a side elevational view of a hand truck simi-lar to Fig. 3, but showing the hand truck as being tilted against the deck of a truck with a modified arrangement for supporting the back of the truck against the corner of the deck;
Fig. 12 is a fragmentary detail view of a leg per se .
used in the truG~ shown at Fig. 11 to further illustrate the sup-porting member;
Fig. 13 is a fragment of the back side of the leg shown at Fig. 12 to illustrate further the manner of connecting the support to the leg; and Fig. 14 is a sectional view as taken from the indicated line 14-14 at Fig. 12, but on an enlarged scale.
The common two-wheel hand truck is used extensively to handle heavy, rigid, box-like loads, especially on a one man job.
The body of such a truck consists of a pair of upright rails which are spaced apart by crossbars and these rails are tipped to hold a load at their front faces. A lip outstands from the bottom edge o the front faces of the rails to reach underneath a load to pick it up and to place it upon the rails when the truck is tipped.
Two spaced-apart wheels are mounted upon a shaft at the back side of the rails and at the bottom of the truck so that when the ~ruck is tilted, it will be upon these wheels. Finally, a handle is provided at the top of, and at the back side of, each rail to enable an operator to hold the truck. In picking up a load, the operator pushes the truck against the side of a box-like load and :, . . . . :
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pushes the lip underneath it. He then tips the truck and the load rearwardly to place the load upon the truck. So posi-tioned, an operator can balance the load over the wheels and easi-ly move the loaded truck to its destination~
Such hand trucks are useful for moving loads across level, smooth surfaces, but they are awkward to handle when they must be lifted or lowered, such as up and down a stairway, and even more so where the lift is a substantial distance such as from the ground surface to a truck bed or from a ground surface to a loading dock. In many instances, ramps are provided where such lifting pxoblems exist, but pulling a loaded hand truck up a ramp is hard muscle-straining work, while guiding a truck down a ramp involves the risk of the l~ad getting away from the operator.
It follows that there is a need for an improved system for handling heavy loads with hand trucks where they must be Li~t-ed or lowered vertical distances as to and from truck beds and loading docks. The present invention was conceived and developed with the above considerations in view and comprises, in essen~e, a two-wheel hand truck having a pair of downwardly extendible legs forming part of an eleva~ing mechanism for raising and lower-ing the hand truck. In the preferred embodiment, the elevating legs are within hollow, slotted rails to telescopically extend therefrom. The rail slots permit the legs to be tied together to assure their movement in unison. The truck structure is aLso modified to an arrangement which permits the legs to be extended below the truck without interfering with the regular structural components o~ the truck. The legs are forcibly e~tended by a suitable, simple, chain-pull mechanism which is operated by a crank located on the hanclle at the top of the truck. Safety brake features may be included in this organization to prevent the crank from getting away from an opera-tor and also hold the truck wheels.
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, " ,, , . ' .:
Referring more particularly to the drawing, Figs. 1 to 10 depict a preferred embodiment of the invention, a two-whee:L
hand ~ruck T. This hand truck is essentially conventional in its general form and can be used the same as a standard hand truc]c.
The body of the truck T includes a pair of longitudinal upright rails 20 which are held apart in spaced parallelism. These rails are slotted, tubular members and the bottoms are open to carry extension legs E as hereinafter described. The other regular components of the truck are mounted upon the rails in an arrange-ment which will not inter~ere with the movements of these exten-sion legs.
A transverse pickup lip 21 outstands from the front face of the body at ~he bottom of the rails to lift a load which is to be tilted against the front of the body when the truck is be-ing used in a conventional manner. Left and right side wheels 22 are mounted upon a transverse shaft 23 behind the rearward faces of the rails 20 and near the bottom of these rails, with a wheel being at each outer side of each rail. The shaft 23 is held in position by bearing clips 24, and a clip 24 is affixed to the outward side of each rail 2~ with the shaft 23 projecting thererom to carry the wheeIs 22, as best shown at Fig. 3.
The two parallel rails 20 are held apart and in position at the bottom of the truck by ~ face plate 25 weIded or otherwise fastened to the front faces of the rails. Preferably, the face plate 25 is formed by folding the rearward portion of the lip 21 upwardly to lie against the front face of the rails. These rails are also held apart and in position at the top of the truck by a transverse structural pipe or tube 26 extending between and being securely welded to the rails. Other intermediate structural com-ponents may also be included to hold these rails in position pro-viding they are at the front or rear faces of the rails and in a position which will not interfere with the movement of the exten-:-- 6 --.
~ s~
sion legs as hereinafter described. In addition, a number of pli-able straps 27 may be spaced between the rails at the outer face thereof to hold a load thereon.
To complete the conventional arrangement, a transverse, tubular handle 28 is carried at the rear end of bars 29 projec-ting rearwardly from the top of each rail. In the present inven-tion, ~he handle 28 is modified to carry a transverse crankshaft, as hereinafter described.
This essentially conventional arrangement of a two-wheeL hand truck, as above described~ is modified to carry an ex-tension mechanism E by using tubular or hollow rails 20 as hereto-fore mentioned. These rails are rectangular in cross~section and have elsngated slots 30 at the~inner face of each rail which ex-tend the entire length of the rails. So positioned, the slots ; 30 in the rails oppose each other. Structural steel hollow sec-tions suitable for the purpose are commonly available in various standard sizes. For example, a suitabIe size for the purpose is a 2 x 4-inch hollow rectangular tube of 14 or 16 gage thickness h~v~ng a 2-inch slot at one~face, the slot 30 at the inner face of each rail 20.
The extension mechanism E includes a pair of legs 31 and a leg 31 is slidably fitted into each xail 20 to project from the bottom of the truck body. The legs 31 are interconnected by rung-like cross bars 32 in a ladder-like arrangement at;any seLected spacing, and although two cross bars 32 are shown, any number of cross bars, and even diagonal brace bars, may be select-ed for the purpose. Thé cross bars 32 extend from the opposing xail slots 30 between the rails and thus the legs may freely slide into and out of the rails 20 without *he cross bars 32 interfering with the structure of the truck T.
Since the truck will be lifted upon and supported by these legs 31, as illustrated at Fig. 1 and hereafter further . .: :" ' . . .
. . :, . .... ~ . . ~ , :
~5~35~3 described, the base of each ley 31 is desirably fitted with an anti-slip shoe 33, a U-shaped member having an anti-slip under-surface, having its side portions connected to the base of each leg by a pivot 34 so that the shoe can be tipped to adjust to any tilt of the hand truck, or irregularity of the ground sur-face.
It is desirable to have the legs 30 to move in the rails with a free, easy sliding action. Accordingly, the legs 31 are rectangular in cross section, similar in form to the rails 20 but smaller so that they may telescope into the rails with a free-sliding fit. To minimize frictional resistance to movement of the legs within the rail, the top of each leg 31 is formed as I a clQvis-like crotch to hold a roller 35 upon a short shaft 36 ~'~ between the arms of the crotch.' The roller 35 will bear against ;~ the front face or rear face of the railæ, inside the rails, to keep the top portion of the legs from dragging. To minimize the~frictional resistance of a leg 30 bearing against the base of each rail 20, an anti-friction slide plate 37 is located at the front side of the base of the rail passageway and a rollex 38 is carried upon the whéel shaft 23 to project through an open-ing 33 in the back side of the rail 20, the'slide 37 and roller 38 being best sho'w~at Figs. 4 and 9.
The extension legs 3I are forcibly extended downwardly from the body o the truck and upwardly into the truck by turll-ing a crank 40 mounted upon a transverse shaft 41 which extends ~'~
through the transverse, tubular handle 28. ~he handle 28 is locat~d approximately 9 inches or so behind the rails, and is supported by the shbrt flat bars 29, as heretofore described.
For a right-hand operator, the crank'40 is located at the out-- -ward æide of thé right-hand bar 29. The shaft 41 transmits torque to a drive sprocket 42 mounted on the'shàft 41 at the center of the handle 28. The handle 28 is divided into two . ~ , . . ~ . . . : " , . .
, , ; , - . :
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.
ii615~3 sections to allow for this sprocket. The sprocket 42 and other mechanisms ar~ housed in a simple gearcase 43 in thP form of a plate, folded to an inverted U and mounted at the center of the truck between the handle 28 and the spacer rod 26. The drive sprocket 42 is connected by a chain 44 to a torque-increasing sprocket 45 carried upon a shaft 46 within the gearcase 43, as shown at Fig. 6. The shaft 46 also carries a driven sprocket 47, connected with the torque-increasing sprocket to rotate therewith, and a lift chain 48, extending to ~he base of the truck is car-ried on the driven sprocket 47.
The lift chain 48 extends downwardly between the rails,at tha back side of the truck and to the bottom of the truck to an idler sprocket 50 mounted upon the'wheel shaft 230 The lift chain 48 thus forms a loop about the drive sprocket 47 and the idler spxocket 50. A clip 51 at the forward reach of this chain loop connects with'a sel:ected cross bar 32 which interconnects the:extension legs 3I. Accordingly, the'rotation of the crank 40 I turns the several sprockets wi:thin the gearcase 43'to operate the I lift:chain, which,' in turn, will extend or retract the elevator E to raise and lower the truck T to,various positions such as il- :
lustrated at Fig. 1. When lifting the truck, the entîre pull of the :chain will be upon the idler sprocket 50, and upon the wheel : ' !
shaft 23. To facilitate supporting this shaft 23,' the shaft :is carried in tubular support sections 52, as illustrated at Fig. 9, ' .
and these sections are supported by struts,53, as best illustrat~
ed at Figs. 2,,7 and 8. The movement of the extension legs from the rails 20 is 1imited by the location of the clip 51 or chaln 48 with~respect to the legs 31 since this clip cannot move down~
wardly beyond thé sprocket 50 about which the chain 48 turns.
ThIs clip is necessarily located a short distance from the top of the legs 31 below the roller 35, as upon a crossbar 32, as best:illustrated at Fig. 5. This permits the upper portion of :::
_ g _ :
", . ,, ....... , , , . , . : . ~ , .
ea~h leg 31 to remain within the embrace of the rails 20 when the leys are, operatively, fully extended. Such prevents a buck-ling of the leg~ at the bottom of the rails such as would occur if the top of the legs were at the bottom of the rails. This lo-~ cation of the clip 51 with respec't to the top end of the legs 31 ; thus provides a structure which will not be overstressed when the legs are, operatively, fully extended. A properly proportioned arrangement, such as that illustrated, can be easily determined by any skilled designer.
A crank brake 54 of a standard type which is normally locked and which will reIease only when the crank 40 is turned, is mounted upon the outer face of the handle support bar 29 adja-cent to the'crank 40. This brake prevents~the truck from acci-clentally,,suddenly dropping if an operator accidentally releases the handle 40 and is an important safety ~eature. This brake may be a conventional type, such as the hand brake manufactured by the Fulton Mfg. Co. of Milwaukee,,Wisconsin, cataloged as , No. 560 hand brake and hence it need not be described.
In addition to the automatic crank-brake 54 to prevent the truck from dropping when it is loaded, a hand brake 55 is pro-vided for preventing rotation of the wheels 22. This hand brake is conveniently located at ,the'left side of the truck in associ- ;, ation with the handle 28 so that an operator may apply the brake 55 wi,th his left hand while cranking with his right hand. The hand brake,55 is formed as a gripper bar adapted to lie along-~ side the handle 28 and to be pulled thereagainst. As such, it '~ is carried upon a lever arm 56 pivotally connected to the left side bar 29 as best illustrated at Fig. 7. The lever, in turn, is connected with a pair of braking cables 57 and 58 which are housed in cable sheaths 59 and 60~ respectively. The cable ,, sheaths 59 and 60 extend from the bifurcation point of the cables to the'interior of the support tube 26 to divert to the left and , 58~
right hand sides of the truck, as best illustrated at Fig. 8.
The sheaths then extend from their respective ends of the tube and through the walls of the rails 20 to lie alongside the outer - face o~ the respective rails to extend downwardly alongside the rails and to terminate at a point near the wheel 22 at the base ; of the truck. Each brake cable 57 and 58 extends from its shea~h and connects with a lever arm 61 adjacent to the wheel 22. I'his lever arm includes an outstanding tab 62 to engage the wheel.
Each lever 61 is pivotally connected to the rail in a position to move the pad 62 against the wheeI whenever its cable 59 or 60 is ' pulled upwardly. A spring 63 opposing the cable tends to normal-ly pull the pad away from the wheel. It follows that whenever an operator squeezes the brake handle, both'of the cabIes will be ~' pulled to lock both wheelc.
It is a relatively simple~ matter to lift a loaded two-wheeI hand truck with the elevator E ~he eIevator is normally kept at a retracted position and a load is placed' upon the hand truck in a conventional manner. The hand truck is then tipped to ride upon the wheels 22 on a level' surface'to ihe' rear of a vehicle or to the edge of a dock whereon it is to be lifted. The hand truck is then moved to rest in a tipped position against the edge'of the vehïcle'or dock as illustrated at Fig. 1. Next, the operator will get upon the d~ck of the vehicle'or dock to hold the hand truck in place'and he commences to turn the crank 40 with ;~ his right hand to cause thé elevator legs to be'extended downward-ly, lifting the truck and its load. By continuing this cranking operation, the hand truck is raised to a poink where'the wheels 22 ride over the edge o~ the vehicle tailgate or dock. The hand brake 55 locks the whéels 22 to prevent the truck from getting away ~rom the operator, and the elevator legs may then be re-tracted to permit the hand truck to continue its trip on the vehicle or dock to bring the load to its destination.
.:
,, , '' , An operation to lower a load from a vehicle or a dock to the ground surface is easily accomplished in substantially the same manner, but wi-th the steps being in the opposite sequence.
; The hand truck is rolled to the edge of the dock, the hand brake 55 is applied to prevent the loss of the load. Next, the legs 30 are extended downwardly to engage the lower surface and to then lift the vehicle and its load from the dock or truck deck.
Subsequently, the truck is lowered downwardly to the base eleva-tion of the vehicle deck or dock.
In order to slide the hand truck smoothIy against the edge of a vehicle dock or tailgate and to ease the wheels 22 over this edge, a slide bar 65 i5 secured to the~rearward side of each rail to engage the edge of the dock or tailgate. The slide bar extends from a point near the top of the hand truck to a position adjacent to the wheeIs 22 as illustrated and it is spaced reax-wardly ~rom the rearward edge of the rail to provide clearancl_ for the lift chain 48 and to provide a smooth transition from the ~ -~, slide bar to the wheels 22 as they move upon the deck of a vehicle i or dock. A slide bobbin 66 may be mounted upon each slide bar 65 to be held against the edge of a vehicle tailgate or loading dock deck, as illustrated at Fig. 1. This bobbin may be a simple, plastic member, as illustrated at Fig. 10, and it may be propor-tioned to slide freeIy upon its bar 65. A small frictional drag may be provided by a clip 67 so that the bobbin can be placed at i any select~d position upon the slide barO It is also contemplat-ed that the slide bar 65 will be of fairly hard material and ~will freely slide along the edge of a truck deck or loading dock i~
the bobbin is not used.
Other arrangements for easing the sliding action of the back edge of the rails 20 against the edge of a tailgate or dock are also pQs~ible, such as slide pads at the edge of the tailgate or dock or a pulley-belt arrangement at the back of the rails.
, . . . . .
"
Such arrangements are not shown since they are entirely conven-tional.
An alternative arrangement for holding the rear edge of the hand truck away from the corner of a vehicle deck or load-ing dock deck is illustrated at Figs. 11, 12 and 13 where a fend-er 70 is provided on each leg 31' to contact the corner of the deck. This finder 70 is formed as a looped arm which extends be-hind the rear edge of the hand truck and extends downwardly from the arm in spaced parallelism with the leg 32'. The spacing of each fender 70 from the truck rails is at a distance sufficient to straddle the shaft 23 and roller 38 upon this shaft to permit the wheels 22 to move past the fender arms and onto the deck in - a manner ess~ntially the same as heretofore~described.
I have n~w described my invention in considerable detail.
However, it is obvious that others skilled in the art can build and devise alternate and equivalent cs~nstructions which are never-theIess within the spirit and scope oiE my invention. Hence, I
desire that my pro-tection be limited not by the constructions il-lustrated and described, but only by the proper scope of the ap-20 pended claims.
'", ,"
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Claims (12)
1. A two-wheel hand truck having an elevator mechanism to facilitate raising and lowering the hand truck to and from an elevated deck and comprising:
(a) a hand truck, the basic structure of which in-cludes a pair of longitudinally extended tubular rails open at their bottom ends, a transverse pickup lip outstanding from the bottom front edge of the rails, a pair of spaced wheels mounted upon a transversely disposed wheel shaft adjacent to the bottom back edge of the rails and a handle at the top of the rails, all in an arrangement which permits a load to be picked up by the lip and lie against the front side of the rails when the truck is tipped rearwardly onto the wheels;
(b) said elevator mechanism including a leg tele-scopically carried in each rail with the length of the leg approaching the length of the rail;
(c) an extension means to extend and to retract a substantial portion of the legs from the bottom of the rails in unison to raise and lower the truck with a load thereon to a height which is a substantial portion of the height of the hand truck; and (d) a cranking means to operate the extension means.
(a) a hand truck, the basic structure of which in-cludes a pair of longitudinally extended tubular rails open at their bottom ends, a transverse pickup lip outstanding from the bottom front edge of the rails, a pair of spaced wheels mounted upon a transversely disposed wheel shaft adjacent to the bottom back edge of the rails and a handle at the top of the rails, all in an arrangement which permits a load to be picked up by the lip and lie against the front side of the rails when the truck is tipped rearwardly onto the wheels;
(b) said elevator mechanism including a leg tele-scopically carried in each rail with the length of the leg approaching the length of the rail;
(c) an extension means to extend and to retract a substantial portion of the legs from the bottom of the rails in unison to raise and lower the truck with a load thereon to a height which is a substantial portion of the height of the hand truck; and (d) a cranking means to operate the extension means.
2. In the organization defined in claim 1 wherein:
the inner side of each rail is slotted and the legs are joined together by cross bars extending from the slots.
the inner side of each rail is slotted and the legs are joined together by cross bars extending from the slots.
3. In the organization defined in claim 2, wherein:
the extension means includes a pull chain connected to a cross bar and extending downwardly therefrom to a connect-ing means near the bottom of the hand truck.
the extension means includes a pull chain connected to a cross bar and extending downwardly therefrom to a connect-ing means near the bottom of the hand truck.
4. In the organization defined in claim 2 wherein:
the extension means includes a transverse shaft near the top of the hand truck, a second transverse shaft near the bottom of the hand truck, a sprocket on each shaft, a chain loop between the sprockets having one point connected to a cross bar of the legs and said cranking means is associated with a sprocket to forcibly pull the chain loop about the sprockets and lower the cross bar with respect to the rails when the legs are being extended.
the extension means includes a transverse shaft near the top of the hand truck, a second transverse shaft near the bottom of the hand truck, a sprocket on each shaft, a chain loop between the sprockets having one point connected to a cross bar of the legs and said cranking means is associated with a sprocket to forcibly pull the chain loop about the sprockets and lower the cross bar with respect to the rails when the legs are being extended.
5. In the organization defined in claim 4 wherein:
the aforesaid truck handle comprises a tubular member positioned behind the rails and said cranking means includes a shaft through the handle, a hand crank connected with the shaft at one side of the handle and gear means operatively interconnect-ing the shaft and the aforesaid top shaft sprocket.
the aforesaid truck handle comprises a tubular member positioned behind the rails and said cranking means includes a shaft through the handle, a hand crank connected with the shaft at one side of the handle and gear means operatively interconnect-ing the shaft and the aforesaid top shaft sprocket.
6. In the organization defined in claim 5 wherein:
said gear means includes a drive sprocket connected to the crank shaft at the center of the handle, said top shaft parallels the crank shaft and the aforesaid top shaft sprocket thereon connects with the said drive sprocket through a driven sprocket on the said top shaft which, in turn, connects with the said top shaft sprocket.
said gear means includes a drive sprocket connected to the crank shaft at the center of the handle, said top shaft parallels the crank shaft and the aforesaid top shaft sprocket thereon connects with the said drive sprocket through a driven sprocket on the said top shaft which, in turn, connects with the said top shaft sprocket.
7. In the organization defined in claim 4 wherein:
the aforesaid second transverse shaft near the bottom of the hand truck is. the said wheel shaft and means to support this shaft at each side of the bottom shaft sprocket.
the aforesaid second transverse shaft near the bottom of the hand truck is. the said wheel shaft and means to support this shaft at each side of the bottom shaft sprocket.
8. In the organization defined in claim 5 including:
a braking means associated with the said hand crank adapted to prevent rotation of the crank whenever the same is released.
a braking means associated with the said hand crank adapted to prevent rotation of the crank whenever the same is released.
9. In the organization defined in claim 1 including:
a slide means at the back side of each rail adapted to hold the rails away from an edge of an elevated deck where-onto the truck is being lifted or wherefrom the truck is being lowered.
a slide means at the back side of each rail adapted to hold the rails away from an edge of an elevated deck where-onto the truck is being lifted or wherefrom the truck is being lowered.
10. In the organization defined in claim 9 wherein:
each slide means comprises a rigid slide bar spaced rearwardly from the back side of the rails and a slide spool thereon adapted to engage the edge of the deck to permit the slide bar to slide within the spool.
each slide means comprises a rigid slide bar spaced rearwardly from the back side of the rails and a slide spool thereon adapted to engage the edge of the deck to permit the slide bar to slide within the spool.
11. In a two-wheel hand truck of the type having a pair of longitudinally extended rails, a transverse pickup lip out-standing from the bottom, front edge of the rails, a pair of spaced wheels mounted upon the truck in transverse axial align-ment with a wheel being at each side of the truck near the bottom back edge of a rail, and a handle means at the top of the rail, all in an arrangement which permits a load to be picked up by the lip and to lie against the front side of the rails when the truck is tipped rearwardly onto the wheels;
the improvement consisting of an elevator mechanism to facilitate raising and lowering the hand truck to and from an elevated deck and comprising:
(a) a leg having a length substantially the length of said rail is telescopically associated with each rail to normally nest within the rail, but to extend downwardly below the bottom of the rail; and (b) a manually actuated cranking means interconnect-ing the legs to forcibly move said legs in unison to extend a substantial portion of the legs below the rails and to retract the same whereby to raise and lower the truck to and from an elevated deck whose height is a substantial portion of the height of the truck through such extension and retraction of the legs.
the improvement consisting of an elevator mechanism to facilitate raising and lowering the hand truck to and from an elevated deck and comprising:
(a) a leg having a length substantially the length of said rail is telescopically associated with each rail to normally nest within the rail, but to extend downwardly below the bottom of the rail; and (b) a manually actuated cranking means interconnect-ing the legs to forcibly move said legs in unison to extend a substantial portion of the legs below the rails and to retract the same whereby to raise and lower the truck to and from an elevated deck whose height is a substantial portion of the height of the truck through such extension and retraction of the legs.
12. In the organization defined in claim 11, wherein:
said manually actuated cranking means includes a braking means adapted to hold the legs at any position whenever they are being extended and to retard and/or stop the movement of the legs whenever they are being retracted.
said manually actuated cranking means includes a braking means adapted to hold the legs at any position whenever they are being extended and to retard and/or stop the movement of the legs whenever they are being retracted.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA231,748A CA1050583A (en) | 1975-07-18 | 1975-07-18 | Two-wheel hand truck with elevator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA231,748A CA1050583A (en) | 1975-07-18 | 1975-07-18 | Two-wheel hand truck with elevator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1050583A true CA1050583A (en) | 1979-03-13 |
Family
ID=4103634
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA231,748A Expired CA1050583A (en) | 1975-07-18 | 1975-07-18 | Two-wheel hand truck with elevator |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1050583A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1984002499A1 (en) * | 1982-12-23 | 1984-07-05 | Norris Terrence W | Hand trolley |
| US5741169A (en) * | 1997-03-04 | 1998-04-21 | Chen; Hwa-Lo | Device capable of climbing on top of an obstruction |
-
1975
- 1975-07-18 CA CA231,748A patent/CA1050583A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1984002499A1 (en) * | 1982-12-23 | 1984-07-05 | Norris Terrence W | Hand trolley |
| US5741169A (en) * | 1997-03-04 | 1998-04-21 | Chen; Hwa-Lo | Device capable of climbing on top of an obstruction |
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