Joist scaffold unit

Information

  • Patent Grant
  • 6749041
  • Patent Number
    6,749,041
  • Date Filed
    Monday, December 23, 2002
    22 years ago
  • Date Issued
    Tuesday, June 15, 2004
    20 years ago
Abstract
A joist scaffold unit including first and second vertical legs of adjustable length disposed generally parallel to one another. Horizontal crossbars of adjustable length extend between the first and second legs. A foot is pivotally attached to the bottom end of each leg and configured to be secured to a ceiling or floor joist. A vertical brace extends from the leg or the crossbar at an angle to the ceiling or floor joist. A foot at the end thereof is configured to be secured to the ceiling or floor joist. A supporting structure is placed over spaced-apart of joist scaffold units to allow construction workers to work on a roof or the like.
Description




BACKGROUND OF THE INVENTION




The present invention generally relates to scaffolding used in building construction and the like. More particularly, the present invention resides in a scaffold unit which is attachable to joists of a floor or ceiling to facilitate repairs and construction of a roof or ceiling.




The use of scaffolding in the construction industry is well known. For example, scaffolding may be constructed on an exterior of a building to facilitate plaster or paint work. Traditionally, scaffolding has been constructed of frame members which are assembled and placed a set distance apart from one another on a flat surface, such as the ground or a floor. Planks are laid across the assemblies in order to allow construction workers and the like to be elevated to the working area.




However, such scaffolding has certain disadvantages. For example, the end metal units are typically non-adjustable in height. Adjustability is provided by stacking scaffolding units upon one another, or selecting a scaffolding which meets the requirements of the user. Also, when constructing a roof, it is common to have ceiling or floor joists underlying the ceiling during the framing and construction process. This presents a challenge for traditional scaffolding.




Accordingly, there is a continuing need for a scaffolding structure which is particularly suited for the construction and repair of roofs and ceilings when floor or ceiling joists are positioned below the intended work area. Such a scaffolding structure should preferably be adjustable in width and height so as to accommodate the needs of the construction worker. The present invention fulfills these needs and provides other related advantages.




SUMMARY OF THE INVENTION




The present invention resides in a joist scaffold unit which is particularly designed for use on floor or ceiling joists, which typically comprise wood beams running parallel to one another to create the supporting structure for the floor or ceiling. The joist scaffold unit generally comprises first and second vertical legs of adjustable length disposed generally parallel to one another. Horizontal crossbars of adjustable length extend between the first and second legs. A foot is pivotally attached to a bottom of each leg, so as to be secured to the floor or ceiling joist. The foot includes a generally U-shaped bracket configured to receive an edge portion of a joist therein.




Each leg comprises a main body having a first end telescopically and slidably received within an upper riser. A second, lower end of the main body is telescopically and slidably received within a lower riser. Thus, the legs can be adjusted in height. The main body and upper and lower risers have alignable adjustment apertures for receipt of a locking pin or the like to fix the legs at the desired height. Each crossbar is comprised of a tubular first segment which telescopically and slidably receives a second segment extending from the opposite leg. The first and second segments include alignable adjustment apertures for receipt of a locking pin therethrough to fix the width of the legs so that the feet can be properly positioned over the floor joists.




A brace of adjustable length extends from the leg or the crossbar of the scaffold at an angle towards the floor joist. A foot which is pivotally attached at an opposite end of the brace is configured to be secured to the ceiling or floor joist. Such foot includes a generally U-shaped bracket configured to receive an exposed portion of the joist, and preferably includes a fastener extendable through the foot and into contact with joist to securely connect the foot thereto. The brace is preferably comprised of a first tube that telescopically and slidably receives a second tube so as to be adjustable in length. The first and second tubes include a linable adjustment apertures for receipt of a locking pin therethrough to lock the brace at the desired length.




In use, one joist scaffold unit is secured to floor or ceiling joists, and a second is secured to floor or ceiling joists and spaced from the first joist scaffold unit. Planks or the like are then placed over the upper most crossbars to provide a supporting surface for the construction workers to be elevated with respect to the floor ceiling joists and work on the roof above.











Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.




BRIEF DESCRIPTION OF THE DRAWINGS




The accompanying drawings illustrate the invention. In such drawings:





FIG. 1

is a partially exploded perspective view of a scaffolding unit embodying the present invention;





FIG. 2

is a cross-sectional view taken generally along line A—A of

FIG. 1

, illustrating the adjustable nature of legs of the scaffolding unit; and





FIG. 3

is a top plan view of the leg and crossbar unit of the invention.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




As shown in the accompanying drawings for purpose of illustration, the present invention resides in a scaffolding unit, generally referred to by the reference number


10


, which is particularly adapted for use in constructing or repairing roof structures when floor or ceiling joists lie below.




With reference now to

FIGS. 1-3

, the scaffolding unit


10


is comprised of first and second legs


12


and


14


having crossbars


16


extending therebetween. The vertical legs


12


and


14


are adjustable in length. In the illustrated particularly preferred embodiment, each leg


12


or


14


comprises a main body


18


having a first and telescopically and slidably received within an upper first riser


20


. A lower end of the main body


18


is also slidably connected to a lower riser


22


. This enables the legs


12


and


14


to be adjusted to a desired height. The various segments of the legs


12


and


14


include apertures


24


therethrough which are alignable within one another to receive a locking pin


26


such as a cotter pin or the like. In this manner, the height of the legs


12


and


14


can be fixed in place.




The crossbars


16


are also adjustable in length, or width, so as to alter and provide adjustment to the width of the structure


10


. With reference to

FIGS. 1 and 3

, each crossbar


16


is comprised of a tubular first segment


28


extending from one of the crossbars


12


or


14


, and a smaller second segment


30


extending from the opposite leg


12


or


14


. The second segment is telescopically and slidably received within the first segment


28


to provide width adjustment. The first and second segments


28


and


30


include alignable apertures


32


which receive a locking pin or the like to fix the relationship of the first and second segments


28


and


30


at the desired width.




To provide stability and strength, preferably, multiple crossbars


16


extend between the first and second legs


12


and


14


, although as few as a single upper crossbar


16


may be utilized in accordance with the present invention. As shown in

FIGS. 1 and 2

, notches or slits


34


are formed in the upper riser


20


so that the upper riser


20


is lowered onto the main body


18


in a crossbar


16


extending between the main bodies


18


of the first and second legs


12


and


14


will be received within the slot


34


. Similar slots


34


can be formed on either the main body


18


or lower riser


22


for the same purposes.




A foot


36


is pivotally attached to the bottom end of each leg


12


and


14


. The foot


36


is a generally U-shaped member which is sized and configured such so as to be slipped over an exposed edge of the floor or ceiling joist. Such floor and ceiling joists are one to two inches in thickness, thus the foot


36


is sized so as to fit over such edge of the joist. The feet


36


are pivotally attached to the legs


12


and


14


so that a construction worker is not limited to positioning the scaffold unit


10


running parallel to the ceiling or floor joist, but rather can elect to set up the joist scaffold perpendicular to the joist. In use, two joist scaffold units


10


are set up so that they are spaced from one another. A plank, or the like, is placed on the upper crossbars


16


of each to provide a working and supportive surface for the construction workers.




It has been found that although the feet


36


prevent lateral movements of the joist scaffold units


10


, forward or backward motion is still a possibility. Thus, the invention incorporates a vertical brace


38


which extends from either the legs


12


and


14


or crossbar


16


downwardly to a lower joist. The brace


38


includes an attachment means, such as the illustrated eyehook


40


which is received onto the legs


12


and


14


or braces


16


. In a particularly preferred embodiment, the eyehook


40


is sufficiently large so as to be received on the crossbars


16


or ends of the upper riser


20


and extend diagonally therefrom to the joists. A joist foot


42


is pivotally attached to the brace


38


at an opposite end thereof. The joist foot


42


is also a generally a U-shaped member sized so as to be positioned over an exposed edge of a joist. The joist foot


42


includes an aperture


44


for receipt of a thumb screw or other fastener which can be inserted through the joist foot


42


and into contact with the joist so as to fix the joist foot in place.




In a particularly preferred embodiment the brace


38


is adjustable in length. The brace


38


is comprised of a first tube


46


which is hollow so as to slidably and telescopically receive a second tube or rod


48


. Each tube


46


and


48


includes apertures


50


which are alignable with one another so as to receive a locking pin therethrough for fixing the length of the brace


38


. Typically in use, a brace


38


will extend from each leg


12


or


14


, or two braces


38


will extend from the crossbars


16


to provide a stable support for the construction worker.




A method of constructing the joist scaffolding unit


10


as described will now be provided. First, the main body


18


must be built. A 1″×3″ square tubing having a length of 24″ is provided. A 1″×1″ square tubing having a length of 23″ is welded thereto to form the first cross-bar segment


28


. On the opposite main body


18


, a ⅞″×⅞″ square tubing having the length of 23 inches is welded thereto so as to be aligned with the first segment


28


. This square tubing comprises the second segment


30


which is slidably received in the first segment


28


. Holes, ½″, are drilled through the crossbars


16


so as to accept a {fraction (7/16)}″ pin. The lower riser is comprised of ⅞″×2⅞″ square tubing having the length of approximately 28 inches. The crossbars


16


are formed generally in the same manner. The lower riser


22


can thus slide into the main body


18


. Holes, ⅝″, are drilled into the main body


18


and lower riser


22


to provide adjustment apertures. Thus, the lower riser


22


and main body


18


can be adjustably positioned from as little as 2′ in height to as much as 4′ in height. Slots


34


are created in the main body


18


as necessary to accommodate the lower riser


22


crossbar


16


.




The top riser is comprised of 1⅛″×3⅛″ square tubing having the length of approximately 32″. The crossbar


16


is assembled in the same manner as the others, and preferably the top crossbar


16


is welded at approximately 4″ below the top and bottom of the upper risers


20


. This enables the supporting plank to have side stability when placed over the units


10


. Notches or slots


34


are formed in the upper riser


20


so as to receive the crossbars


16


extending between the main body


18


. Similar adjustment holes


24


are formed in the upper riser


20


so as to receive a pin


26


or the like through aligned apertures


24


of the various segments of the legs


12


and


14


. The addition of the upper riser


20


enables the legs


12


and


14


to be raised approximately two more feet.




The feet


36


are then attached to the lower ends of the lower risers


22


. The U-shaped feet are approximately 1½″ in width. A hole is drilled therethrough and a pin or rivet type pin or bearing is used to connect to joist feet


36


to the lower riser


22


in a swivel-fashion.




Finally, the vertical brace


38


is created for stability. A 1¼″ diameter round tube is provided which accepts a 1″ iron rod or tube therethrough. Each segment is approximately 4′ long. The ends of the tubes are capped, if necessary, and the eyehook


40


is attached at an upper end thereof. Preferably, the eye of the hook


40


must be large enough to slip over the crossbars


16


. Holes of approximately ½″ in diameter are drilled into the tubes


46


and


48


. A joist foot


42


is attached to the lower end of the brace


38


, as described above. An aperture


44


is drilled through the joist foot for receipt of a hand-tum bolt such as a wing nut or the like which is able to grip the wood joist. Typically, a piece of iron or metal is fitted around the crossbar


16


on the inside of each vertical brace


38


to insure that the vertical brace


38


does not slip from the its place. These are preferably removably attached for adjusting purposes.




Although an embodiment has been described in detail for purposes of illustration, various modifications may be made without departing from the scope and spirit of the invention.



Claims
  • 1. A joist scaffold unit, comprising:first and second vertical legs of adjustable length disposed generally parallel to one another; horizontal crossbars of adjustable length extending between the first and second legs; a foot pivotally attached to a bottom end of each leg, and configured to be secured to a ceiling or floor joist; and a brace of adjustable length extending from the lea or the crossbar at a first end thereof, and having a foot pivotally attached at an opposite end thereof configured to be secured to a ceiling or floor joist; wherein the leg and brace feet each include a generally U-shaped bracket configured to receive a portion of a joist therein.
  • 2. The scaffold unit of claim 1, including a fastener extendible through the foot and into contact with the joist to securely connect the foot thereto.
  • 3. A joist scaffold unit, comprising:first and second vertical legs of adjustable length disposed generally parallel to one another; horizontal crossbars of adjustable length extending between the first and second legs; a foot pivotally attached to a bottom end of each leg, and including a generally U-shaped bracket configured to receive a portion of a joist therein; a fastener extendible through the foot and into contact with the joist to securely connect the foot thereto; a brace of adjustable length extending from the leg or the crossbar at a first end thereof; a foot pivotally attached at a second end of the brace and including a generally U-shaped bracket configured to receive a portion of a joist therein; and a fastener extendible through the brace foot and into contact with the joist to securely connect the brace foot thereto.
  • 4. The scaffold unit of claim 3, wherein each leg comprises a main body having a first end telescopically and slidably received within an upper riser, and a second end telescopically and slidably received within a lower riser, the main body and upper and lower risers having alignable adjustment apertures for receipt of a locking pin.
  • 5. The scaffold unit of claim 3, wherein each crossbar is comprised of a tubular first segment which telescopically and slidably receives a second segment, the first and second segments including alignable adjustment apertures for receipt of a locking pin therethrough.
  • 6. The scaffold unit of claim 3, wherein the brace is comprised of a first tube that telescopically and slidably receives a second tube, the first and second tubes including alignable adjustment apertures for receipt of a locking pin therethrough.
  • 7. A joist scaffold unit, comprising:first and second vertical legs of adjustable length disposed generally parallel to one another, wherein each leg comprises a main body having a first end telescopically and slidably received within an upper riser, and a second end telescopically and slidably received within a lower riser, the main body and upper and lower risers having alignable adjustment apertures for receipt of a locking pin; horizontal crossbars of adjustable length extending between the first and second legs, wherein each crossbar is comprised of a tubular first segment which telescopically and slidably receives a second segment, the first and second segments including alignable adjustment apertures for receipt of a locking pin therethrough; a foot pivotally attached to a bottom end of each leg, and including a generally U-shaped bracket configured to receive a portion of a joist therein; a fastener extendible through the foot and into contact with the joist to securely connect the foot thereto; a brace of adjustable length extending from the leg or the crossbar at a first end thereof, wherein the brace is comprised of a first tube that telescopically and slidably receives a second tube, the first and second tubes including alignable adjustment apertures for receipt of a locking pin therethrough; a foot pivotally attached at a second end of the brace and including a generally U-shaped bracket configured to receive a portion of a joist therein; and a fastener extendible through the brace foot and into contact with the joist to securely connect the brace foot thereto.
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Number Name Date Kind
1376924 Dixson May 1921 A
1474250 Folliord Nov 1923 A
1841676 Roberts Jan 1932 A
3508628 Conrad Apr 1970 A
3628628 Gilbrect Dec 1971 A
3917214 Ratcliff Nov 1975 A
4531613 Keigher Jul 1985 A
4858726 Preston Aug 1989 A
5114024 Meissner May 1992 A
6073726 McCrystal Jun 2000 A