The present invention relates generally to lifting devices and, more particularly, to lifting devices for lifting an article from a ground level to a work surface or table or support surface, such as in a wood working or metal working shop or the like.
It is known to provide lifting mechanism that raise and lower a platform to raise and lower an article relative to the support surface or ground at which the platform is positioned. Such lifting mechanisms are typically scissor-type lifting mechanism and require the article to be substantially centered and balanced on the platform before the platform may be raise to lift the article.
The present invention provides a lifting assist device or leveraged lift assist device that allows a user to place an end or a portion of a heavy article (such as a large piece of plywood or particle board or drywall or the like or such as an elongated metal or wood beam or the like) on the support platform of the lift assist device, whereby the user may readily tilt or pivot the lift assist device towards a vertical orientation to raise the other or distal end or portion of the article above the ground, so as to allow for raising the article to a table or other support by a single person. The lift assist device may be vertically nonadjustable or manually adjustable, whereby the support platform is not vertically moved relative to the base of the lift assist device during use of the device (with the user selecting and presetting the length or height of the lift assist device before use), or optionally the list assist device may be powered or automated, whereby, after the end or portion of the article is positioned at or on the support platform, the user may tilt the lift assist device toward its vertical orientation and also may lift or raise the support platform upward (such as via a linear actuator or pneumatic actuator or cylinder or the like) to raise the article to a desired height for positioning the article on a table or other support surface.
According to an aspect of the present invention, a lift assist device for assisting a user in lifting an item includes a base having a center portion and a side portion that is angled relative to the center portion, a support shaft extending upward from the center portion of said base, and a support platform attached at an upper end of the support shaft. The lower end of the support shaft is attached at the center portion and the support platform is rotatably attached at the upper end of the support shaft and rotatable about an axis that is generally parallel to a longitudinal axis of the support shaft. The lift assist device is tiltable between a loading position, where the side portion of the base rests on a floor or support surface and the support shaft is in a tilted orientation, and a lifting position, where the center portion of the base rests on the floor or support surface and the support shaft is in a generally vertical orientation.
Optionally, the support shaft may be adjustable in length to adjust a height of the support platform relative to the base, and the support shaft may be manually adjustable or automatically adjustable responsive to the position of the lift assist device.
According to another aspect of the present invention, a method for lifting an article off of a support surface includes providing a lift assist device having a base, a support shaft and a support platform. The base has a center portion and a side portion that is angled relative to the center portion. The support shaft extends upward from the center portion of the base, and has a lower end attached at the center portion and an upper end opposite the lower end, and the support platform is attached at the upper end of the support shaft. The method includes tilting the lift assist device to a loading position, where the side portion of the base rests on a floor or support surface and the support shaft is in a tilted orientation, and lifting an end of an article onto the support platform when the lift assist device is in the loading position, whereby the lifted end of the article is supported by the support platform and an opposite end of the article is supported at the support surface. With the end of the article supported on the support platform, the lift assist device is tilted to a lifting position, where the center portion of the base rests on the floor or support surface and the support shaft is in a generally vertical orientation. The opposite end of the article is raised above the support surface when the lift assist device is tilted to the lifting position.
Therefore, the present invention provides a lift assist device and method of lifting articles that assists a user in lifting heavy objects or articles. The lift assist device is particularly suited for assisting a user in lifting heavy articles, such as large sheets of plywood or particle board or drywall or the like or elongated beams or the like, from a support surface or floor or ground up and onto an elevated target support surface or table, such as a workbench or work table or the like, where the user may process or work on the lifted article. The lift assist device provides the lifting function via the balanced configuration of the lift assist device and the leverage it provides when a portion of the object or article is supported on the lift assist device. A user of the lift assist device of the present invention thus may readily lift a portion of an article onto the lift assist device and then, using the lift assist device as a fulcrum and to provide the desired leverage, may readily raise the un-supported or opposite end portion of the article to a desired level or height to generally align the article with the elevated target support surface or table.
These and other objects, advantages, purposes and features of the present invention may be readily understood upon review of the following specification in conjunction with the drawings.
Referring now to the drawings and the illustrative embodiments depicted therein, a lift assist device 10 includes a base or base portion 12, a support shaft or rod 14 with a lower end 14a attached to and extending upward from base 12, and a support platform 16 attached at an upper end 14b of support shaft 14. Base 12 includes a first or generally central portion 12a, from which support shaft 14 extends upwardly therefrom, and an angled or curved portion 12b that curves upwardly from the first base portion 12a, such that the lift assist device 10 can be tilted between a supporting or lifting position (
In the illustrated embodiment, support platform 16 comprises a generally planar platform portion 16a, with downwardly angled or curved side regions or portions 16b. The downwardly angled support platform portion 16b may allow the operator to begin the loading process of the lift assist device when the lift assist device is in its non-tilted orientation, such that when the end portion of the article is raised onto the support platform, the article may contact one of the downward extending lifts 16b and may cause the lift assist device to move or pivot or tilt toward its tilted orientation (
As can be seen in
Support shaft 14 may comprise any elongated shaft or rod, with its lower end 14a attached at the central base portion 12a of base 12, and with its upper end 14b attached at support platform 16 (or at rotating bracket 18). In the illustrated embodiment, support shaft 14 comprises a telescoping shaft having a hollow lower shaft portion 20 and an upper shaft portion 22 slidably or adjustably received in an upper end portion of lower shaft portion 20. As best shown in
Base 12 may comprise any suitable material, such as a metal plate or the like, and may be formed such that the angle or curved base portion 12b angles or curves upwardly from the central or support shaft mounting portion 12a to allow the base 12 to tilt from its untitled position (
As shown in
Thus, during use, a user of the lift assist device 10 may first set the degree of extension of a support shaft 14 to a desired amount (such as by setting the height of the support platform 16 at or near the height of a targeted support surface or cable or the like at which the article is to be placed). When the desired height of the lift assist device has been set, the user may tilt the lift assist device so that it is supported on the angled base portion 12b, and may then manually lift an end or portion of the article (such as a large sheet of plywood or particle board or drywall or the like, or such as an elongated beam or the like) and may place the end or portion of the article on the support platform 16. The user may place the portion of the article on the support platform, such that the end of the lifted portion of the article extends beyond the support platform, whereby the user may push downward on that end portion of the article while pulling back on the lift assist device, in order to pivot the lift assist device toward its supporting position (
When the lift assist device is in its supporting position of
Optionally, although shown as having slippage limiting rubber protrusions 16c spaced over the upper surface of the support platform, other support surfaces may be implemented while remaining in the spirit and scope of the present invention. For example, other rubber coatings or elements may be disposed at the upper surface of the support platform to assist in limiting slippage of the article relative to the support platform during use of the lift assist device. Optionally, however, the support platform may provide movement enhancing means to assist in moving or sliding the article back onto the support platform and off of the support platform and onto the targeted support surface or table. For example, the support platform may include a plurality of rollers or the like that facilitate rolling of the article in one or more directions on the support platform to ease the operator's efforts in loading and unloading the support platform. It is envisioned that such rollers may comprise rotatable balls that allow for multidirectional movement of the article on the support platform, and it is envisioned that such rollers or balls may be selectively lockable to allow for selective movement of the article and selective non-movement of the article to provide enhanced control of the movement and loading/unloading of the article by the user of the lift assist device.
Also, although shown as having a telescoping support shaft that is adjustable to provide varying heights or degrees of lift of the lift assist device, other types of support shafts may be implemented, while remaining in the spirit and scope of the present invention. For example, the support shaft may have a fixed length, whereby the lift assist device is not vertically adjustable and may lift the article to desired or various heights by tilting the lift assist device back toward and onto the second angled portion 12c of the base 12. Optionally, other types of adjustable support shafts may be implemented, such as a manually hand-crank type of support shaft (whereby the user may turn a crank to cause extension or retraction of one shaft portion relative to another) or any other suitable means for extending and retracting the support shaft to raise and lower the height support platform relative to the base.
Optionally, it is envisioned that the lift assist device may be vertically adjustable when the end portion of the article is loaded onto and support by the lift assist device. For example, after the end portion of article is loaded onto support platform and the lift assist device it tilted toward its non-tilted position, the user may selectively adjust the height of the support platform (or the lift assist device may automatically adjust the height of the support platform) to raise the support platform and article partially supported thereon to a desired level. Such a configuration allows for loading of the article onto a lower or unraised support platform, where further lifting of the article to the desired height (so as to generally align the article with the height of the elevated targeted support surface or table) is done by the lift assist device and not by the user or operator. Such vertical adjusting of the lift assist device when loaded may be done any via suitable adjusting means, such as via a manual hand-crank or the like that the operator may turn or actuate to raise or lower the support platform the desired amount, or such as via a power assist system or mechanism or device, which may automatically raise the support platform or article to a desired level or height responsive to a user input or other triggering device or event.
For example, and with reference to
In the illustrated embodiment, the actuator or actuating device or mechanism 130 comprise a pneumatic actuating device, which includes a control valve 132 that is connected to a pressurized air source 134 (such as via an air supply line 136 or the like) and is selectively operable to pressurize a pneumatic actuator or cylinder 138 to cause extension of a piston and rod 138a of the pneumatic cylinder 138 and support shaft 114. As best shown in
Actuation of the switch 144 (such as via depressing the switch toward the control valve 132 as discussed below) causes the control valve 132 to allow for passage of pressurized air from the air source 134 to the lower or input end of the pneumatic cylinder 138, thereby moving the piston and rod 138a along the pneumatic cylinder 138 to raise the support platform 116 relative to base 112. Optionally, and desirably, when the switch 144 is no longer depressed, and moves away from the control valve 132, the control valve 132 may vent the pressurized air in the air cylinder 138 via the relief port 142 to cause or allow retraction of the piston rod 138a back into the pneumatic cylinder 138, thereby lowering the support platform 116 relative to the plate 112. As best shown in FIG, 10, the control valve 132 is mounted at the lower end 114a of support shaft 114 (which comprises a pneumatic cylinder 138), and switch 144 extends downwardly from the control valve 132 and is aligned with and extends at least partially through an aperture or hole 112d formed in the base plate 112 (such as in the central base portion 112a or such as at or near or in the second angled portion 112c).
Thus, during use of powered lift assist device 110, a user may initially tilt the lift assist device to its tilted or loading position (such as shown in
The user may then push down on the end 150a of the beam 150 and/or may pull back on the lift assist device 110 (such as via pulling at a handle 148 of the lift assist device 110 toward the raised end 150a of the beam 150 and away from the distal and non-lifted end 150b of the beam). As the lift assist device is pivoted toward its upright or lifting position (
After the article or beam is aligned with the targeted support surface or table and moved or unloaded from the lift assist device, the user may tilt the lift assist device in either direction to allow for extension of the switch from the control valve to cause the control valve to no longer supply pressurized air to the pneumatic cylinder 138, but instead to vent the pressurized air from the pneumatic cylinder 138 through the relief port or vent 142, thereby allowing the support shaft to retract to lower the support platform back to its lowered position.
Optionally, and as shown in
Optionally, a switch cover or membrane or plate (such as a spring steel plate or flexible plastic or rubber plate or cover or the like) may be disposed at the base and generally at the hole (such as at the bottom or lower surface of base portion 112c of the base 112), in order to allow or enhance the switch to properly function on soft ground or materials, such as when the lift assist device is used in grass or dirt or gravel or the like. The flexible cover or membrane thus limits the extension of the switch and, when depressed, actuates the switch, and the flexible cover provides a greater surface area at the switch-to-ground interface, thereby enhancing performance of the switch when the lift assist device is used on soft ground (and limiting the possibility of the switch extending into the soft ground when the lift assist device is tilted past its upright position). Optionally, the flexible cover or membrane may be enlarged and the hole in the plate may be enlarged to provide a greater surface area interface for the switch, depending on the particular application of the lift assist device.
Optionally, the lift assist device may include a pedal or foot actuator or element that allows the user to depress or step down on or at the second angled portion of the base to assist in pivoting the lift assist device from its loading position to its support or lifting or raising position, such as when an object or article is supported at the support platform. For example, and with reference to
The foot pedal 150 provides enhanced control of the tilting of the lift assist device and allows the user to use both hands to hold and steady the article supported on the support platform 116 (particularly for lightweight articles or sheets of plywood or the like that may otherwise slide off of the support platform when the user pulls back on the handle 148 to tilt the lift assist device to its upright or lifting position). The foot pedal 150 may also provide added leverage to assist the user in tilting the lift assist device (with an article supported thereat) from the loading position to the lifting or support position, and may provide enhanced control of actuating the switch 144 to actuate or control the control valve 132 during use and operation of the lift assist device. The foot pedal 150 may comprise an extension of the angled base portion 112c or may comprise a separate attachment or pedal bolted or otherwise attached to the angled base portion 112c, and the foot pedal 150 may extend generally parallel to the angled base portion 112c or may be bent or angled relative to the angled base portion to provide an angled surface that the user may more readily place their foot on during use and operation of the lift assist device.
Optionally, the lift assist device of the present invention may include a larger support platform or may include extension supports (such as elongated rods or beams or brackets) that extend from the support platform generally in the direction of tilting to assist in supporting larger items or articles, such as large sheets of plywood or the like. For example, and again with reference to
The support rods provide additional support for an article being lifted by the lift assist device, such as a large, lightweight sheet of plywood or laminate or the like (which may be flexible or non-rigid): For example, the support rods may provide enhanced support for large sheets (such as a four by twelve sheet of plywood or laminate or the like) that may otherwise bend or flex during lifting so that they are difficult to lift and load onto a raised surface or table. The support rods provide support to the lifted end of the article and allow for a generally flat or non-flexed or non-bent end of the article that can then be readily guided onto the elevated support surface or table when the lift assist device is raised to the desired or targeted elevation.
Although shown and described as a pneumatic actuator or actuating device or mechanism or system that is operable responsive to a switch at the base plate 112, clearly other means for selectively extending and retracting the support shaft to raise and lower the support platform and article supported thereon may be implemented while remaining within the spirit and scope of the present invention. For example, the actuator or actuating device or extension/retraction mechanism may comprise any suitable actuating means, such as a hydraulic actuator or cylinder (such as a single action hydraulic cylinder or a double action hydraulic cylinder or the like) or any other linear actuator device or the like. Optionally, actuation or control of the extending/retracting actuator may be performed via any suitable means, such as a switch of the type shown and described above (that automatically actuates the actuator responsive to the tilting of the lift assist device during use), or a switch or user input or inputs at the handle 148 or the like, where a user may selectively control the raising and lowering of the support platform during use of the lift assist device via actuation of an appropriate user input or switch or button.
Thus, the present invention provides for a lift assist device that facilitates relatively easy lifting and moving of heavy objects by a single person, with substantially reduced efforts required by the person and with the person never having to lift the entire article or object by himself or herself. The lift assist device, and the base plate and support platform, are substantially balanced to allow for relatively easy tilting and stabilizing of the lift assist device at its tilted orientation, and the configuration of the lift assist device provides the appropriate leverage to facilitate and enhance the tilting back of the lift assist device to its generally upright or lifting orientation, and thus to enhance the raising of the distal end of the article supported by the lift assist device, whereby the article may be readily held and maintained at its lifted state.
In the illustrated embodiment, the support shaft is mounted to the central or bottom base portion of the base plate and is off-center relative to the base plate, while the support platform may also be mounted off center on the support shaft (such as can be seen with reference to
Changes and modifications to the specifically described embodiments may be carried out without departing from the principles of the present invention, which is intended to be limited only by the scope of the appended claims, as interpreted according to the principles of patent law.
The present application claims the filing benefit of U.S. provisional application Ser. No. 61/482,673, filed May 5, 2011, which is hereby incorporated herein by reference in its entirety.
Number | Date | Country | |
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61482673 | May 2011 | US |