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The present invention relates to the field of cranes, hoists, and lifting devices.
This invention teaches improvements to portable hoists that are mountable to vehicles, building structures, carts, trailers, and the like. Examples in prior art are abundant and include teachings by Harr and Cary who introduce portable cranes in U.S. Pat. Nos. 5,752,799 and 5,993,137. Kruse teaches a in U.S. Pat. No. 6,007,289 that mounts into a receiver hitch and uses a jig to stabilize and increase the lifting capability of a hoist that is designed for powered mobility chairs. Williams teaches a portable mobility chair crane in U.S. Pat. No. 6,830,423 that engages a vehicle receiver adapter. Robinette teaches a low-pivot-point lift in U.S. Pat. No. 5,211,526 that does not have a hinge point.
Spitsburgen teaches a portable lift in U.S. Pat. No. 6,499,610 for medium to heavy applications. The '610 apparatus is readily assembled before each use and can be disassembled after use for easy storage. The Spitsburgen lift is mountable to vehicles, equipment, trailers, and building structures. Griffith teaches recoverable installation of a hitch hoist that is suitable for heavier objects in Canadian Patent 2,108,107. Davis teaches a multi-purpose hoist in U.S. Pat. No. 5,749,697 with top and bottom components mate together during assembly. Likewise Barger teaches a portable crane in U.S. patent application Ser. No. 10/657,029 that is adaptable to shop work benches, vehicles, and other stable structures. Amato teaches a swingable boom-type portable crane in U.S. Pat. No. 4,881,864 that engages the receiver hitch of a vehicle.
Compton teaches a collapsible hoist in U.S. Pat. No. 6,152,675 that has a sufficiently high center mast to elevate hunting game; the hoist is assembled, installed, and subsequently removed between uses. A collapsible hoist taught by Perkins in U.S. Pat. No. 6,578,722 also engages a vehicle receiver hitch and has a telescoping mast that is able to achieve a sufficient height to raise tall objects. Phillip and Angel teach similar game hoists in U.S. Pat. Nos. 6,705,821 and 7,201,552.
Other exemplary embodiments are described in U.S. Pat. Nos. 6,478,528, 6,386,820, 5,520,498, 5,445,487, 5,014,863, 7,300,238, 6,981,834, 6,860,703, 6,138,991, 6,089,431, 6,082,561, 5,810,547, 5,788,095, 5,800,117, 5,662,451, 4,417,665 and US patent application publication 20110206488.
All examples and combinations of examples of portable cranes found in prior art rely on assembly before use and disassembly after use. Among the above listed examples, the '675, '522, '722 and '821 cranes share the additional common drawback that they do not pivot. US Patent Application US2009/0067968 A1 also teaches a portable crane that requires assembly between uses and does not pivot. Prior art is quick to point out that each phase of assembly can be performed in as little as 2 minutes.
The present invention unveils a notable improvement by teaching a hoist that unfolds into a usable state in as little as 2 seconds and folds into a stowed state just as quickly. No assembly is required to transition the present invention in an operable state and no disassembly is required to revert the present invention back into a stowed state. To achieve this improvement over prior art the present invention combines a low profile pivoting hinge with latching and stopping surfaces, a hinge mounted mast with latching and stopping surfaces, and a hinge mounted boom with latches and stopping surfaces that automatically lock the hoist into operable and stored states as it is folded or unfolded. Nothing found in prior art or any combination thereof is seen to describe the present invention.
This invention teaches improvements to portable hoists. The principal improvement over prior art is the capability to unfold into an operable state without additional steps to assemble or secure the hoist. Other improvements over prior art include knee-operable rotational load control, safety measures to enable the apparatus to remain assembled and engaged to a receiver hitch while in tow, a telescoping kick-stand style jig, the capability to fold into a stowed state without additional steps to disassemble or secure the hoist, and a pivoting hinge that is designed to engage the stanchion in a manner that improves lifting capacity and product safety.
Further features, advantages, and benefits of this invention, as well as the structure and operation of various embodiments thereof, are described in detail below with reference to the accompanying drawings. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digits in the corresponding reference number. The drawings disclosed herein are illustrative of preferred and sample embodiments of the disclosed invention and are not intended to limit the spirit or scope thereof.
The present invention is a portable crane that is able to fold in and out of operative states without the need for assembly or disassembly between uses and is able to remain assembled while in tow. Essential components of this invention include a pivot shaft 240, boom latch 220, load coupler 250, and an assembly comprising a stanchion 210, pivot hinge assembly 230, and boom 260; all having locking surfaces automatically engage as the hoist is folded between operable and stowed states.
Embodiments of this invention are shown unfolded into an operative state in
The term “stanchion” refers herein to a component of the hoist 210 that operates as a substantially vertical mast when the hoist is unfolded into an operable state. The stanchion 210 of the present invention has a locking surface at the distal end 211 that engages the upper surface of a pivot hinge 231 as the apparatus is unfolded. The stanchion 210 also has a locking surface at the proximal end 212 that engages the distal surface 221 of the boom lock. The pivot hinge 230 and the boom lock 220 are defined below.
The term “pivot hinge” refers herein to a component 230 that is hinge coupled to the base of the stanchion 210, has a substantially horizontal upper surface 234 that engages the locking surface at the distal end 211 of the stanchion as it is unfolded into a locked operative position.
The term “pivot shaft” refers herein to a substantially cylindrical shaped shaft 240 that is rotationally coupled to a pivot hinge 230 and adaptively coupled to a receiver adapter 770.
The term “boom” refers to a lifting arm 260 that is adaptively coupled to a load coupling device 250 when the hoist is in use. The boom 260 is substantially horizontal in both operational and stowed states in preferred embodiments of this invention.
The terms “boom latch” and “boom lock” interchangeably refer herein to a latch 220 that is hinged coupled at the distal end 221 to the distal region 261 of the boom 260 and has at least one locking surface at its distal end 222 that engages a locking surface at the proximal end 211 of the stanchion 210 as this invention is unfolded into an operable state.
The term “mounting base” refers to any structure that is capable of supporting the crane assembly and load during use and has an insertion opening 770 that can be adaptively coupled to the pivot shaft 240. 710, 810, 910, 1010, 1110 are exemplary embodiments of mounting bases that are usable with for the present invention.
The term “insert adapter” refers herein to a substantially vertical cylindrical opening 770 adaptable to mate with the pivot shaft during recoverable installation of the hoist to the mounting base 710.
Preferred embodiments of the present invention employ additional latches 1210, 1310, 1610, jigs 1510, boom extenders 1410, actuators 1810, and winches 1630, 1710 to improve performance or utility of the present invention for specific applications.
The term “base latch” refers herein to a latching mechanism 1210 that engages and secures the proximal end 211 of the stanchion 210 to any surface on the mounting base as the present invention is folded into a stowed state.
The term “stanchion latch” refers herein to a latching mechanism 1310 that engages and secures the stanchion 210 to the boom 260 as the present invention is folded into a stowed state.
The term “boom extender” refers herein to an insert 1410 that is preferably attached to a load coupler and can be inserted into the boom 260 to collectively extend the reach of the boom 260. The adaptively coupled position of boom extender 1410 inside the boom 260 is adjustable in preferred embodiments.
The term “kick-stand jig” refers herein to a hinge mounted jig 1510 that operates substantially in the same manner as a kick-stand. The jig relies on a spring 1520 or other means of mechanical tension to force the jig to snap into operable and stowed states. The top of the jig includes an upper surface that engages and locks to a lower surface on the mounting base when the jig is unfolded into an operable state.
The term “rotational swing lock” refers herein to a rotational latch 1620 at the base of the pivot hinge that is capable of adaptively coupling with a plurality of surfaces 1621 at the distal end 211 of the stanchion 210 or the lower end 235 of the pivot hinge 230 to control pivotal rotation.
The term “tilt lock” refers herein to a releasable latch 1610 at the distal end 211 of the stanchion 210 that engages a locking surface 233 on the pivot hinge 230 to prevent the stanchion 260 from folding backward into a stowed state while it is unfolded into an operative state.
In preferred embodiments, the pivoting hinge 230 serves as a supporting stop for the stanchion 210 as it is unfolded, the boom lock 220 drops and locks into place as the lifting arm 260 is raised into operating position, and safety latches 1210, 1310 engage the stanchion 210 and boom 260 when it is folded back into storage. Preferred embodiments position the pivoting hinge 230 at a low elevation on the structure to give a folded embodiment of the present invention a low profile.
Preferred embodiments rely on two essential features to improve lifting capacity and operational safety; namely a pivot hinge 230 that adaptively couples to the stanchion 210, and a pivot shaft 240 that is rotationally coupled through the pivot hinge 230. The pivot hinge 230 and pivot shaft 240 mate by passing the pivot shaft 240 through a substantially vertical cylindrical opening in the pivot hinge 230. In preferred embodiments the vertical height of the cylindrical opening on the pivot hinge 230 is substantial enough to distribute force along the shaft 240.
In preferred embodiments, the pivot shaft 240 is designed to be a weak point in the apparatus that slowly bends to lower a load that is heavy enough to induce failure in the crane. The sample illustration in
Assembly of the essential components comprises the steps of rotationally coupling the pivot hinge 230 and pivot shaft 240 as shown in
A preferred assembly of the pivot shaft 240 and pivot hinge 230 is shown in
Preferred embodiments of the pivot hinge 230 have a substantially horizontal upper surface 234 that engages the distal end 211 of the stanchion as it is unfolded into a locked operating position. The upper surface 234 of the pivot hinge is preferably angled slightly downward toward the proximal end 232 of the pivot hinge 230. The proximal end 232 of the pivot hinge 230 preferably has a substantially horizontal locking surface 233 that engages a tilt lock 1610 to prevent unintentional folding of the stanchion 210 when in use.
The pivot hinge 230 and stanchion 210 are preferably hinge coupled in a manner that maximizes surface contact between the distal end 211 of the stanchion 210 and the upper surface 231 of the pivot hinge 230. An exemplary embodiment of the pivot hinge 230 and stanchion 210 assembly is shown in
Preferred embodiments of the boom lock 220 include a hinge coupling point at the proximal end 222 and a locking surface at the distal end 221 that engages a locking surface at the proximal end 211 of the stanchion 210. Bends and gussets along the edges of the boom lock 220 are preferably used to enhance strength.
Preferred boom 260 embodiments include a hinge coupling point 264 that is offset slightly from the center of the distal end 261 as shown in
Preferred base latch embodiments 1210 include a spring affixed to the latch to ensure proper engagement to a mating surface 712 on the mounting base 710.
Embodiments of the present invention are adaptively attachable to any plurality of mounting bases. Exemplary embodiments of mounting bases include a vehicle receiver hitch mounting base 710, a base to a portable cart or portable engine hoist 810, mounting base attachments for trailers and portable carts 910, adaptable inserts for tables or working benches 1010, and adaptable inserts for roof, floor, and wall mounts 1110.
The mounting base embodiment 710 shown in
Preferred embodiments of the receiver hitch adaptable mounting base 710 include a kick-stand style jig 1510 at the proximal region 712 of the mounting base 710. The kickstand jig includes a hinge coupling point that is offset from the distal end 1511, a plurality of segments 1513, 1514 that provide height adjustment, a base at the proximal end 1512, and a spring 1520 or other mechanical means to force the kickstand jig to snap into operable and stowed states as it is folded and unfolded.
Accessories such as hand-brake winches 1630, electric winches 1710, and actuators 1810 are interchangeably attachable to preferred embodiments of the present invention.
Essential steps of the preferred method include disengaging latches and locks and unfolding the apparatus from a stowed state, ensuring that all latches and locks that lock the hoist into an operative state are engaged before use, coupling the apparatus to a load, raising the load, optionally engaging a rotational latch to control pivotal rotation, swinging the load into a desired position, lowering the load, uncoupling the hoist from the load, swinging the hoist over the mounting base, and disengaging all latches and locks that lock the hoist into an operative state, folding the apparatus back into a stowed state, and ensuring that all latches and locks that lock the apparatus into a stowed state are engaged.
It is optimal to use this invention on a level surface to minimize the threat of damage to the hoist, host vehicle, or payload and further to impede the threat injury to the hoist operator. If this invention is used on an uneven surface, a preferred method is to level the hoist by making height adjustments to the kickstand jig 1510. If a load must be lifted from an uneven or un-level surface, a preferred method to prevent damage or personal injury is to engage the rotational swing latch until the load can be transported to a level surface.
The present invention is well suited for most lifting applications. Spreaders 1920 should be used when lifting large objects such as lawn mowers, equipment, or all-terrain vehicles 1910. The kickstand style jig should also be deployed when lifting heavy loads; particularly those that approach the limit of the device that supports the mounting base. More than one lifting point should be used on the load as shown in
The present invention is well suited for hunting applications and can be used to winch in large game and to subsequently elevate the animal for processing. The exemplary application in
If the present invention is used to lift logs or other durable items, it may be beneficial to simply wrap the lifting cable of the hoist around the load and use the load coupling hook to form a noose with the cable as shown in
The present invention is well suited for lifting powered mobility chairs and other light loads when affixed to the rear of a vehicle as shown in
It is understood that the above embodiments and applications are merely illustrative of the possible specific applications which may represent principles of the present invention. Other embodiments may readily be devised in accordance with the principals herein by those skilled in the art without departing from the scope and spirit of this invention.