Patent Application
20160145879
The present invention relates generally to a drywall lift which is based upon a four-bar linkage and is operable by a single person.
The increased use of drywall in housing means the ability to easily and efficiently install drywall is essential to home contractors. The need is even greater for ceiling installations of drywall, as it is difficult for a single person to install drywall to ceilings. There is a need to improve the existing methods and tools for installing drywall to ceilings.
One current method of installing drywall sheet to the ceiling employs the use of two men and two cripples. A cripple is a T-shaped brace constructed commonly of two 2″×4″ boards; usually the boards are about 2 & 8 feet long respectively. The two men carry the drywall sheet, holding it by its edges. Then the two men rotate the sheet up over their heads. First one man uses one hand to grab a cripple and place the cripple under the sheet. Then the second man does the same, and then the sheet is lifted to the ceiling. The cripples are wedged between the floor and ceiling to hold the sheet in place. Next drywall screws are used to attach the sheet to the ceiling rafters. This method works, but is not without its drawbacks. For one, a light-weight panel of drywall (4′×8′×½″ thick) weighs 40 pounds. This is a cumbersome weight even for a two man team, let alone an individual worker: it is nearly impossible for a single person to install a panel of drywall to a ceiling without help.
To assist individual workers with drywall installation, there are a number of drywall lifts available. An example of a common drywall lift is one that works on the same principle of a single telescoping tube center assemble. The tube is mounted to a tripod base. A rack, which holds the drywall sheet, is connected to the top of the tube assembly by a hinge. A hand-operated crank, connected to a cable, pulley, and hoist, allows the tube to be moved up and down. This is similar to a boat hoist. These devices are desirable for a number of reasons: they are operable by a single person, work well, and have been adopted by numerous commercial contractors. However, there remains room for improvement. They are somewhat complex, expensive, heavy, and require a large amount of effort is required to rise the drywall ceiling. Furthermore, they are slow; even though they only require a single operator, it takes a lot of turns on the wheel to raise a drywall sheet to the ceiling which slows down the installation process. The present invention seeks to address the shortcoming of current drywall installation methods by providing an apparatus which is easily operated by a single person. In addition to being able to be individually operated, the present invention functions well, and is used by commercial contractors, and some professional installers. However, the exiting lifts are somewhat complex, expensive, heavy, and slow in lifting.
All illustrations of the drawings are for the purpose of describing selected versions of the present invention and are not intended to limit the scope of the present invention.
The present invention is a drywall lift that is operable by a single person. The present invention is designed for quick and easy assembly and disassembly with industry standard fasteners and tools. Additionally, the present invention can be easily handled, assembled, disassembled, and moved by a single non-professional person. The present invention is also projected to be ⅓ of weight and cost of any other existing apparatus that uses to lift drywalls. These said advantages allow the present invention to be an efficient apparatus for home improvement projects that are related to drywall lifting and fills the need for a do-it-self drywall lifting. The present invention is implemented as a mechanical linkage, specifically a modified four-bar linkage, and as such comprises a base link structure 1, an upright link structure 2, a working link structure 3, and a supporting link structure 4. The base link structure 1 and the upright link structure 2 act as fixed links in the present invention, supporting hinged movement of both the working link structure 3 and the supporting link structure 4. These combine into a linkage system with two pivots and one sliding connection. A first pivot is fixed to the upright link structure 2, while a second pivot moves in an arc relative to the first pivot. A sliding connection is between a floor and the bottom of the supporting link structure 4, which drags across the floor during operation of the present invention. These core components of the present invention are subsequently elaborated upon. Illustrations of the present invention are provided via
The base link structure 1 lies flat against a planar surface, e.g. a floor. The upright link structure 2 is connected atop the base link structure 1; these two structures serve as a fixed frame of the present invention. The upright link structure 2, being vertical, is oriented to be perpendicular to the base link structure 1. The working link structure 3 comprises a drywall retaining shelf 31, which allows a drywall panel to independently supported and manipulated (e.g. raised towards a ceiling for connection via ceiling rafters) by the present invention. The working link structure 3 is hingedly connected to the upright link structure 2 through a first axle 5. As a result, the working link structure 3 can be rotated about a fixed end, i.e. the end that is hinged to the upright link structure 2 by said first axle 5. Similarly, the supporting link structure 4 is hingedly connected to the working link structure 3 through a second axle 6. This allows the supporting link structure 4 to be rotated with respect to the working link structure 3. This is important as the supporting link structure 4 can be used to support and secure the working link structure 3 at a non-equilibrium angle. In reference to
In order to further stabilize the structure of the present invention, a first buttress 7 and a second buttress 8 can be installed as part of the present invention. The first buttress 7 and second buttress 8 serve as braces between the base link structure 1 and the upright link structure 2, helping to provide improved stabilization for the present invention. The first buttress 7 and the second buttress 8 are positioned opposite each other across the base link structure 1 and the upright link structure 2. Effectively, the two buttresses are respectively positioned at the left side and the right side of the present invention. Each buttress is positioned at an angle relative to the base link structure 1 and the upright link structure 2; the first buttress 7 and second buttress 8 are both angularly connected between the base link structure 1 and the upright link structure 2, albeit at opposite sides. In short, from a side profile view, the buttresses form a triangular shape in combination with the base link structure 1 and the upright link structure 2. The buttresses can be seen in
The first stay 41 and the second stay 42, being used to support the working link structure 3, are each hingedly connected with the link structure by means of the second axle 6. Resultantly, the first stay 41 and the second stay 42 can be rotated relative to the working link structure 3. As the first stay 41 and the second stay 42 are meant to support the load of the working link structure 3, they are positioned at opposite sides of the present invention. Resultantly, the first stay 41 is positioned adjacent with the first buttress 7 while the second stay 42 is positioned adjacent with the second buttress 8. Each stay effectively remains coplanar with its corresponding buttress; this holds true when resting on a floor at an angle (i.e. when a drywall panel is being loaded onto the drywall retaining shelf 31 and when angled to an upright position (i.e. when a drywall panel is being fastened to a ceiling). It is noted that the first stay 41 and the second stay 42 can be rotated about the second axle 6 independently from each other; this improves safety of the present invention. Even if one of the stays is knocked away or otherwise fails, the other stay remains in place and support the drywall panel and working link structure 3 from falling, resulting in improved workplace safety.
The drywall retaining shelf 31, which receives a drywall panel and secures said drywall panel during rotation towards a ceiling. Thus, the drywall retaining shelf 31 is adjacently positioned with a top surface 32 of the working link structure 3. Furthermore, the drywall retaining shelf 31 is centrally connected to the working link structure 3; this central positioning means that a larger portion of the working link structure 3 will be available to bear the weight of the panel of drywall.
As the present invention is provided for the installation of drywall, and because ceiling heights vary, it is desirable to provide a means of height-adjustment for the present invention. In support of this, the upright link structure 2, the first stay 41, and the second stay 42 each comprise a fixed member 91, an extension member 92, and a locking mechanism 93. The extension member 92 is slidably engaged with the fixed member 91, effectively allowing the extension member 92 to be raised or lowered in relation to the fixed member 91. This allows an operator of the present invention to adjust the extension member 92 to a desired height. The locking mechanism 93 is mounted to the fixed member 91 and selectively engaged with the extension member 92; engagement of the locking mechanism 93 and the extension member 92 prevents movement of the extension member 92. Disengaging the locking mechanism 93 from the extension member 92 allows movement of the extension member 92. The locking mechanism 93 can be reengaged with the extension member 92 once the extension member 92 has been set to the desired height.
A variety of components can be implemented as part of the locking mechanism 93. In the illustrated embodiment, the locking mechanism 93 is preferably a spring-loaded latch. The spring-loaded latch is engaged with the extension member 92 through a plurality of latch receptacles, the plurality of latch receptacles being positioned along the extension member 92. A locking shaft of the spring-loaded latch is pressed against the extension member 92; when the locking shaft is aligned with one of the plurality of latch receptacles, the locking shaft traverses into the latch receptacle. Thus, when the locking shaft is engaged with an arbitrary latch receptacle from the plurality of latch receptacles, movement of the extension member 92 relative to the fixed member 91 is prevented. These are shown in
In other embodiments, as mentioned, different implementations of the locking mechanism 93 can be utilized. For example, in one embodiment the locking mechanism 93 is a clamp; by engaging the clamp pressure is applied to fixed member 91 and the extension member 92. The resulting frictional forces prevent movement of the extension member 92. In another example, the locking mechanism 93 is a screw lock. The screw lock, similar to the clutch lock, applies pressure to the extension member 92 and the fixed member 91 In order to prevent movement. Unscrewing the screw lock releases pressure and allows movement of the extension member 92 to a desired height. In another example, the locking mechanism 93 is a twist-lock similar to a painter's extension pole so that the extensions member 92 is able to move into a desired height in relation to the fixed member 91. This, along with the previous examples, is one of a few possible implementations for the locking mechanism 93 and doesn't not preclude the use of alternative implementations. Components related to the height-adjustable nature are shown through
Just as different implementations are possible for the locking mechanism 93, variations in engagement between the fixed member 91 and the extension member 92 are possible. In the illustrated embodiment the extension member 92 is shown as being adjacently engaged with the fixed member 91. That is, the fixed member 91 serves as a track for the extension member 92. Resultantly, the extension member 92 can slide along the track of the fixed member 91 in order to adjust the height of the present invention. In another embodiment, the extension member 92 traverses into the fixed member 91, resulting in a telescoping connection between the extension member 92 and the fixed member 91. The use of different sliding engagements opens up further possibilities for locking mechanisms 93, such as a twist lock for the telescoping engagement. These two examples shown potential means by which the extension member 92 may be slidably engaged with the fixed member 91; other methods remain possible within the scope of the present invention.
The present invention, as thus far described, serves as a mobile apparatus which allows for a drywall panel to be raised to an elevated height by a single person. In a default position, the working link structure 3 rests against the first buttress 7 and the second buttress 8. The supporting link structure 4, i.e. the first stay 41 and the second stay 42, are rotated such that they are parallel with the working link structure 3. This provides better access to the working link structure 3 for a user of the present invention. In the described position, the present invention is similar to an easel, allowing a drywall panel to easily be loaded onto the working link structure 3 and drywall retaining shelf 31. Once the drywall panel has been loaded, the working link structure 3 can be rotated away from the upright link structure 2 and towards a ceiling as the bottom of supporting link structure 4 slides across the floor and pushes the working link structure 3 and the drywall up to the ceiling. Once the drywall panel has been raised to the ceiling, the supporting link structure 4 is perpendicularly positioned with the floor into an upright position. The supporting link structure's 4 first stay 41 and second stay 42 can be independently, rotated, allowing a user to hold the working link structure 3 up with one hand while rotating the first stay 41 with their other hand. After rotating the first stay 41 to an upright position, a user can then rotate the second stay 42 to an upright position to further stabilize the present invention; with both stays rotated to an upright position, the upright link structure 2, first stay 41, and second stay 42 provide multiple load-bearing sections that are able to hold the working link structure 3 and drywall panel in a raised position. This effectively converts the present invention from a “floor-easel” configuration, i.e. prior to lifting of the drywall panel, to a “support-table” configuration, i.e. when the drywall panel is raised to the ceiling.
With the drywall panel being supported by a present invention, a user has both hands free. The panel can thus be mounted to the ceiling by a single person. This is an improvement over other tools, such as the T-shaped brace known as a “cripple”, which require two persons for drywall installation. Thanks to the height-adjustable nature of the present invention, by means of the first extension member 92 and second extension member 92, the present invention can be adapted for use with ceilings of different height. By moving the extension member 92 of the first stay 41, second stay 42, and upright link structure 2, the total height of the present invention can be increased or decreased. This increases flexibility of the present invention, as it is not limited to ceilings of a specific height.
In the illustrated embodiment, the base link structure 1, the upright link structure 2, and the working link structure 3 each comprise a number of frame pieces. More specifically, the base link structure 1 comprises a first leg 11 and a second leg 12. The upright link structure 2 comprises a first pillar 21 and a second pillar 22. The working link, comprises a first arm 33 and a second arm 34. These components effectively serve as a left side and a right side of the present invention, somewhat similar to the first buttress 7 and the second buttress 8. On one side, the first pillar 21 is connected perpendicular to the first leg 11. On the other side, the second pillar 22 is connected perpendicular to the second leg 12. The drywall retaining shelf 31, which helps secure and bear the load of the panel of drywall, is connected across the first arm 33 and the second arm 34.
The first arm 33 and the second arm 34 are rotatable with respect to the corresponding first pillar 21 and second pillar 22. This coupling is enabled by the first axle 5, which traverses through the first pillar 21, the second pillar 22, the first arm 33, and the second arm 34. The first axle 5 is positioned opposite the base structure along the first pillar 21 and the second pillar 22, allowing the working link structure 3 to be rotated to the same height as the upright link structure 2. The first axle 5 is also positioned opposite the supporting link structure 4 along the first arm 33 and the second arm 34. This positioning maximizes torque; by using the full length of the working link structure 3 as a lever arm, a person is more easily able to lift the working link structure 3.
While the base link structure 1 can be repositioned through simple sliding (except when a drywall panel is being raise; the weight of the drywall panel effectively anchors the base link structure 1 in place), in some embodiments it is desirable to facilitate easier repositioning of the present invention. In such embodiments, lockable wheels, casters, and vertically adjustable feet could be connected to the base link structure 1.
The second axle 6, which allows for rotation of the supporting link structure 4 relative to the working link structure 3, traverses through the first arm 33, the second arm 34, the first stay 41, and the second stay 42. The second axle 6 is positioned opposite the upright link structure 2 along the first arm 33 and the second arm 34; this positioning helps better split the load of the working link structure 3 between the supporting link structure 4 and the upright link structure 2. The second axle 6 is further described as being positioned adjacent to the working link structure 3 along the first stay 41 and the second stay 42; by being positioned at an end of the supporting link structure 4, the second axle 6 allows the full height of the supporting link structure 4 to be used.
In order to better help bear the load of a panel of drywall, the working link structure 3 comprises an at least one cross brace 35. This at least one cross brace 35 is perpendicularly connected with the first arm 33 and the second arm 34. Resultantly, the structural integrity of the working link structure 3 is improved. Potentially, more cross brace 35s could be provided to further increase integrity of the working link structure 3. Furthermore, to help prevent over-rotation of the first stay 41 and the second stay 42, a stop may be connected adjacent to the end of each arm; the stop would prevent the stays from rotating beyond 90 degrees towards the base link structure 1 and upright link structure 2, which aids the operator knowing when both sides of the drywall shelf is in full up 90 degree position.
The components of the base link structure 1, the upright link structure 2, and the working link structure 3, as formerly described, are just one example of a possible implementation for the present invention. As the core concept of the present invention is the use of a four-bar linkage system (via the base link structure 1, upright link structure 2, working link structure 3, and supporting link structure 4), other components can be utilized as part of the link structures without deviating from the scope of the present invention. For example, the base link structure 1 and the upright link structure 2 could be implemented as planar bodies (e.g. a wooden panel) rather than as legs and pillars.
Specific materials and dimensions of the present invention are not restricted; the present invention can easily be fabricated from available materials, such as recycled decking boards. Higher end implantations could be constructed from aluminum or other metals. Likewise, the types of fasteners used are variable; in the illustrated embodiment compression nuts and sleeves are used to install the first axle 5 and second axle. However, in a simpler embodiment, simple screws can be used for connection of the axles. The effort needed to raise the working link structure 3 is also variable. For example, during prototype testing, it was found that lifting effort ranged from 12 to 22 pounds, with initial required effort being low and increasing as the working link structure 3 is raised to the ceiling. The amount of effort required can vary based on the material and dimensions of the present invention, as these can affect weight of the working link structure 3.
While the present invention has been described as a drywall lift, it can be used to raise a variety of building materials. For example, plywood, sheetrock, beams, trims, lighting, heat ducts, fans, and further items can be lifted through rotation of the working link structure 3.
Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.
The current application claims a priority to the U.S. Provisional Patent application Ser. No. 62/083,778 filed on Nov. 24, 2014.
| Number | Date | Country | |
|---|---|---|---|
| 62083778 | Nov 2014 | US |
