Self-adjusting drywall crane

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of PPA Appl. No. 60/577,041 filed Jun. 07, 2004, by the present inventor.

FEDERALLY SPONSORED RESEARCH

Not Applicable

SEQUENCE LISTING OR PROGRAM

Not Applicable

BACKGROUND OF THE INVENTION—FIELD OF INVENTION

This invention relates to drywall lifting devices, specifically to an improved craning mechanism and self-adjusting platform.

BACKGROUND OF THE INVENTION

In the process of building a new home by myself, I was in need of a drywall lift that could be used for 11 feet high walls and ceilings. The standard lifts currently on the market would only reach 10 feet. The model designed to reach 14 feet required the drywall to be lifted 7 feet to place on the platform, which is difficult even for two people. I needed something that I could maneuver easily myself, that would reach the desired heights and that was inexpensive to make. Safety was foremost in my mind, a factor I found lacking in the current market devices. My 30 years of experience as a crane operator helped me to realize this goal.

U.S. Pat. No. 6,010,299 issued on Jan. 4, 2000 to Ronald Jesswein discloses a Lifting and Positioning Device (Prior Art FIG. 1) that has a large number of parts and utilizes an indexing arrangement for positioning the drywall platform. It appears to be heavy and cumbersome, utilizing a floor jack that alone can weigh approximately 65 pounds. A common floor jack also routinely displays cautions on their labels to ‘not get under the object or load being lifted.’

U.S. Pat. No. 6,244,810 B1 issued on Jun. 12, 2001 to Guadalupe Reyes discloses a Drywall Handyman (Prior Art FIG. 3), which utilizes a friction brake. If a panel should need to be lowered, pressure must me applied to a brake handle. Since there is no racheting system to gently lower the panel, the platform and drywall are subject to freefall. I have spoken to many drywall handlers who do not trust these devices.

Accordingly, several advantages of my invention are:

• • (a) A device that has only 7 parts
  • (b) A device that is lightweight, tubular steel, used in building lightweight, strong, load-bearing scaffolding. The total weight is approximately 74 pounds.
  • (c) A device that can be completely assembled in one (1) minute and disassembled in 30 seconds.
  • (d) A device that uniquely utilizes a scissor-lift device (FIG. 1), which is manufacture-rated at a maximum lift capacity of 6500 pounds and can also be used as a stabilizing device to hold up to 6500 pounds when not raising or lowering the drywall.
  • (e) A device that is easily maneuverable when empty or when loaded with drywall and with the platform in any position. It can be easily pushed or pulled over rough surfaces or wires and cables.
  • (f) A device which allows the drywall to be lifted only approximately 20 inches to place on the platform. The platform can be raised to a more comfortable height for a taller person.
  • (g) A device which holds the drywall securely in place, but allows for maximum maneuverability of the drywall sheet into the desired position within 2 inches.
  • (h) A device which lifts and holds a sheet of drywall or lowers the drywall, if necessary, safely and without fear of freefall. It provides a safe environment, even when standing under the platform and drywall.
  • (i) A device that can lift both 8 feet and 12 feet panels and can install panels on a 12 feet high wall or ceiling.
  • (j) A device that embodies a floating, self-adjusting head, which allows for installation of a panel on walls or ceilings at any angle and with no adjustments necessary to any part of the device.
  • (k) A device that can be loaded, operated and allows for installation of a drywall panel by a single person.

SUMMARY

This is a drywall lifting crane that enables a single person to apply drywall to higher ceilings and walls, as found in most currently built homes. It is easily maneuverable and safe to operate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the drywall crane platform in the maximum lowered position.

FIG. 2 shows the drywall crane platform in the fully raised position.

DETAILED DESCRIPTION—FIGS. 1 AND 2—PREFERRED EMBODIMENT

The device consists of a tubular steel tower 1. which is welded to a tubular base that has 2 sets of wheels attached. Two tubular legs 2. are inserted into the tubular base. The legs have a third set of wheels attached to the front to stabilize the device and to make it highly maneuverable.

The lifting device 3. is a scissor-lift, capable of hoisting 6500 pounds. It is bolted to the tower 1. frame. The tubular steel boom assembly 4. is attached to the top of the lifting device 3. with a pin. The top of the boom assembly 4. is attached to the top of the tower 1. with a 5 inch hinge.

The tubular steel boom 5. with the attached drywall cradle 7. is inserted into the boom assembly 4. The drywall cradle 7. is a balanced, pivoting platform, which has been pinned to the base of the boom 5. A tension spring 6. is hooked to the drywall cradle 7. and to the boom 5. to hold the drywall cradle 7. at an approximate 40 degree angle.

OPERATION—FIGS. 1, 2

You need to lift a sheet of drywall approximately 20 inches to place on the cradle 7. lugs, which keep the sheet securely against the drywall cradle 7.

The lifting device 3. is activated by a hand-crank to the desired height. The lifting device 3. will act upon the boom assembly 4. to raise or lower the drywall cradle 7.

When the drywall cradle 7. touches the wall or ceiling to which the drywall is to be secured, the drywall cradle 7. will automatically pivot and level itself off to the pitch of the wall or ceiling.

The entire device can then be rolled to facilitate closer placement, within 2 inches of the nailing position. You can also safely work beneath the entire 8 or 10 foot drywall sheet, since there is no center post to impede maneuverability as in other drywall lifts.

The boom 5. can be lowered safely by reverse cranking the lifting device. 3.

The device can be disassembled in seconds and broken down into 4 parts: The base containing the tower 1. and scissor-lift, the two (2) stabilizing legs 2, and the boom 5. containing the drywall cradle. 7. The largest part of the disassembled device will fit through a 20 inch doorway.

ADVANTAGES

From the description above, it is evident that the process of hanging a sheet of drywall can be done by a single person, with ease of assembly and ease of maneuvering. Above all, this device embodies a high level of stability which enables this process to be done safely.