Scaffolding hoist

Abstract

The most common users of the scaffolding hoist are mason contractors.

Description

FIELD OF THE INVENTION

[0001] This disclosure concerns an invention relating generally to hoists, lifts, elevators, and other devices for lifting objects, and more specifically to such devices which are suitable for use in conjunction with scaffolding or a similar structural framework.

BACKGROUND OF THE INVENTION

[0002] In construction and renovation operations such as roofing, window work, wall masonry, and the like, scaffolding or similar support structures are commonly used to provide elevated surfaces for use by construction personnel. Since building materials, tools, and the like must be transported to the support structure at which the personnel is performing the work, it is common to use forklift, telescopic lift, or “cherry picker” to easily lift the desired items to the support structure. Hoists (also referred to as “lifts” or “elevators”) are also used, and these can be manually driven. As with a cranking winch, or may be motorized.

[0003] Problems are sometimes encountered with the mounting of hoists to the scaffolding or other support structure used to support the working personnel. The driving mechanism (a motor, cranking winch, or other winding mechanism) of the hoist must be affixed to the support structure so that the lift line (the cable, chain, rope, or other line) may be spooled from the driving mechanism at a location where the end of the lift line—which generally bears a basket, hook, or other device allowing tools and materials to be carried on the lift line—may freely descend to the ground, or to whichever level from which the tools and materials are to be lifted. Thus, the driving mechanism must generally be mounted to the support structure in cantilevered fashion, with the driving mechanism (or at least the point on the driving mechanism from which the lift line is spooled) resting over the side of the support structure. Alternatively, the driving mechanism may be mounted to the support structure, and the lift line spooled from the driving mechanism may feed through a pulley which is cantilevered from the side of the support structure. The cantilevered mounting limits the lifting capability of the hoist, since a heavy load may place too much stress on the mounting arrangement or the scaffolding or other support structure. It would thus be useful to have a hoist and/or a mounting arrangement for a hoist, which avoids the problems encountered with prior hoists.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG. 1 is a drawing of an exemplary scaffolding hoist in accordance with the invention, shown installed on exemplary scaffolding.

[0005] FIG. 2 is a drawing of the scaffolding hoist of FIG. 1, shown with most of the scaffolding removed.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0006] Referring initially to FIG. 2, the scaffolding hoist includes a folding V-frame whereupon a driving mechanism is mounted (with a lift line shown descending from the driving mechanism), and one or more optional guide cables descending from the V-frame to an anchor (here shown as a bar extending horizontally from the scaffolding). The V-frame includes a pair of pivotally linked H-frames, wherein one of the H-frames is slightly narrower than the other so that is may be received between the side bars of the other of the H-frame and pivotally linked to these side bars. Thus, the two H-frames may be folded from a position wherein the planes of the two H-frames are nearly parallel, to a position such as the one shown wherein the planes of the two H-frames are situated at a angle to each other. At the base of each H-frame opposite the pivoting link, the bases are furcated so that a horizontal bar of the scaffolding may be received within the furcations (see FIG. 1). As a result, the H-frames may be mounted between two opposing parallel scaffolding bars, even if the scaffolding bars are of different heights, so long as the scaffolding bars are not spaced so far apart that their spacing exceeds the length of the unfolded V-frame (i.e., the V-frame wherein both H-frames are pivoted into the same plane). The furcations include oppositely-spaced apertures so that fasteners may be inserted therein once a scaffolding bar is fit within the furcations, with the fasteners then maintaining the scaffolding bars within the furcations, thereby preventing the bases of the H-frame from being dislodged from the scaffolding bars.

[0007] The driving mechanism is then situated on a bridge provided on one of the H-frames, the bridge extending from one of the side bars of the H-frame to the other. Preferably, this is done so that the point from which the lift line unspools from the driving mechanism is situated below (or nearly below) the pivot axis of the V-frame, thereby enhancing the stability of the V-frame.

[0008] In the drawings, the lift line is shown descending to a basket, and the basket is prevented from swinging during lifting or lowering by slidably affixing its sides to one or more guide cables (with two guide cables being shown in the drawings). The guide cables (which are preferably ropes, wires or similar spoolable materials) ride within eyelets provided on the basket, thereby preventing the basket from swinging about the axis of the lift line during lifting or lowering. The guide cables descend from the V-frame to be attached to any suitable anchor at the ground or other level from which material and/or tools at to be lifted (with a simple anchor being exemplified by the rightmost guide cable in FIGS. 1 & 2). Alternatively, the guide cables may be affixed to the anchor by pulley, eyelet, or other means for slidably receiving the guide cable, with the guide cable then being attached to a winch or other device to allow tensioning of the guide cable (as exemplified by the leftmost guide cable in FIGS. 1 & 2, wherein a cranking winch is provided to tension the guide cable).

[0009] Turing to FIG. 1, it is seen that the hoist may be installed on scaffolding or a similar support structure by simply fitting its furcations between two opposing generally parallel scaffolding bars, with the lift line (and its basket, if provided) then descending downwardly within the interior of the scaffolding. The scaffolding hoist thereby allows a non-cantilevered mounting arrangement for a hoist, thereby increasing its load capacity. The hoist may be easily mounted between scaffolding bars virtually regardless of their spacing and/or relative heights. Additionally, the hoist is easily installed or removed from scaffolding during setup or shutdown.

[0010] The H-frames are shown with a support bar extending between Their side bars for the purpose of adding rigidity, but if desired, the support bar may be removed, allowing each to the side bars of the H-frame to swing to different angular positions to affix to the same or different scaffolding bars. If desired, the side bars of the H-frames may also be formed of telescoping sections to allow the H-frame to collapse or expand to different lengths. For example, one telescoping side bar of the H-frame could be affixed to a scaffolding bar at one height, and the other telescoping side bar could be attached to a scaffolding bar at another height.

[0011] Further, at the base of each H-frame, the furcations could be pivotally affixed to their side bars to allow their rotation about the axes of these side bars, and allow their mounting to scaffolding bars oriented at angles other than the horizontal.

[0012] The description set out above is merely of exemplary preferred versions of the invention, and it is contemplated that numerous additions and modifications can be made. These examples should not be construed as describing the only possible versions of the invention.

[0013] Claims priority over previously filed provisional application on Jun. 11, 2002.

Claims

1. A scaffolding hoist having a frame which folds so that the distance traversed by its base may be varied to extend across and engage different scaffolding sections, the frame preferably being a V-frame with a central pivot point, wherein the frame has a driving mechanism for a lift line thereon.

2. Apparatus as recited in claim 1 at the base of each H-frame opposite the pivoting link, the bases are furcated so that a horizontal bar of the scaffolding may be received within the furcations including oppositely-spaced apertures so that fasteners may be inserted therein.

3. Apparatus as recited in claim 1 having a frame that can be made out of any shape or design of material with rigid or telescoping members.

4. The lift line can be used independently to lift product, buckets, other materials or basket as shown in FIGS. 1 & 2, secured with a guide line for stability of basket.

5. Apparatus as recited in claim 4 comprises of a basket with self-leveling apparatus that connects to the lift line and basket is equipped with eyelets, tubing or other forms for the guide lines to be run through.

6. Apparatus as recited in claim 4 comprising a guideline to be a single or double line run through the basket, secured to unit frame or scaffolding, anchored to cross member and tightened with hand-winch or other tensioning device as shown in FIGS. 1 & 2.