Powered pulse shingle and nail remover/demolition
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Powered Pulse Shingle and Nail Remover/Demolition Tool, the “Demolition Demon”, is a tool composed of a frame, which has a T/D-handle, with an enclosed trigger. The handle is integral to the frame that provides alignment of components and structural strength to the tool as a whole. The “Demolition Demon” is essentially a combination shovel, crowbar, wrecking bar that has an air cylinder driven hammer device mounted on the frame to provide impact power to drive the shovel blade, flat bar, nail claw under the fastener, or cut, scrape, or separate members. This tool has multiple tools that can be attached to the end of the tool driver by using a common interface. The hammer effect is derived from accelerating a large mass over a distance to develop momentum and then impact the tool driver to which the tool is attached. Impact is controlled by a trigger mechanism that operates a multi-port valve. The impact can be adjusted by regulating the pressure at the compressor or by inserting an adjustable pressure restriction valve ahead of the air inlet on the tool.

Kingham, James Richard (Lexington Park, MD, US)
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Primary Examiner:
Attorney, Agent or Firm:
James Richard Kingham (Wiomico Church, VA, US)
1. I claim my invention, the “Demolition Demon”, to be a powered combination tool for removing nails/fasteners and performing demolition work, that uses pulses of energy that are sufficiently powerful as to drive the blade of the tool under the heads of a nails holding shingles to a roof on the first or second pulse. I claim the potential energy generated by air pressure, electrical power (AC or DC), or gas combustion must create a large enough force to generate impact of sufficient strength to accomplish the task at hand, demolition work or nail and shingle removal. I claim the application of impact energy, like a hammer blow, is required to be effective in demolition or roof removal work, not vibratory or reciprocating motion.

2. I claim that by using an air cylinder that has a high mass piston and shaft (with a stroke greater than 2 inches operated with high pressure air (greater than 90 psi) can provide the necessary high impact force to drive the tools blade to the desired position to perform shingle and nail removal or demolition work. I claim, for large tools, the addition of an accumulator may be required to keep the pressure sufficiently high throughout the stroke of the air cylinder. I claim that the use of commercially available multi port valves and pilot valves in conjunction with a high mass piston and shaft air cylinder can be effectively and efficiently controlled to perform the desired function, that of delivering a strong hammer like blow to the tool driver.



I reviewed the following patents and found none that used high impact pulses to perform shingle and nail removal or demolition. Most of the patents call for reciprocating or vibratory motion. Some of the tools suggested are bulky and very hard to manipulate. Others use an air cylinder to pry the nail out of the roof, not to engage the nail head. Still others just rip shingles off the roof without regard to the nails.

U.S. Pat. Nos. 6,128,979; 6,393,948 B1; 6,095,015; 5,906,145; 5,863,100; 5,800,021; 5,741,047; 5,001,946; 5,076,119; 4,858,503; 4,763,547; 4,709,479; and 4,663,995 (Abstracts are attached)


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There exists a need to remove nails and other fasteners from roofs for the purpose of re-roofing a structure. Roofers typically remove all the nails when removing shingles. There is also a need to separate wooden structures that are nailed together (i.e. remove sheathing from a floor, wall or roof). There are many manually operated tools for doing this work, all requiring a lot of physical exertion by the tool user. The “Demolition Demon” provides a means of removing nails and separating members from each other while requiring significantly less physical exertion on the part of the tool operator/user to get under the fastener or between two nailed members. The “Demolition Demon” provides the tool user sufficient controlled power to assist in getting the tool inserted under the fastener/nail or in between joined members and provides a fulcrum for prying the nails/fasteners out of the sheathing or separating members further using the users/operators own power applied to the handle of the tool. The tool by its length and location of the fulcrum near the application of the force, provides a long moment arm to reducing the force required to remove nails or separate joined members.

The use of vibrating or reciprocating motion of a tool to remove nails is ineffective. The motion of the tool is transmitted to the operator and he absorbs the energy not successfully delivered to the point of application. To effectively remove nails, you must first get the blade under the nails then pry them out of the roof sheathing, As a result of testing prototypes and experimentation I have found the most effective way to quickly get the blade under a nail for removing is to use a larger diameter air cylinder with a long stroke with a heavy piston and shaft to drive a tool driver that has a conventional roofing shovel end attached to the tool driver. With one squeeze of the trigger, the blade can be driven under nails lodged in ½″ plywood attaching the shingles to the roof. To remove the nails the operator has only to push down lightly on the handle of the tool, pivoting off the fulcrum.


Preferred Embodiment

The, “Demolition Demon”, consists of a light-weight stiff frame with components mounted along its length. The tool is used much like a conventional hand shovel or crow/pry bar for the removal of nails and roofing materials. This tool has D or T handled frame with a side mounted tubular handle for guiding and controlling the tool manually. Mounting points on the frame provide mounting for the air cylinder, trigger/switch, multi-port valve block, and associated tubing. There are guides incorporated into the frame that locate the tool driver with respect to the air cylinder. The handle has an integral trigger mechanism that operates the multi-port valve used to control the airflow to the air cylinder. The frame has stops that are used to limit the travel of the tool driver. The air cylinder is a mounted double-acting air-cylinder that has a shaft protruding from the nose of the air cylinder. What is unique about this tool is the air cylinder make up and location. The air cylinder is set up something like a jack-hammer, in that it has a heavy piston that creates large forces. Unlike a jack hammer the shaft is attached integrally to the piston and the air cylinder does not cycle when the trigger is squeezed. The air cylinder is triggered by the pilot valve activating the multi-port valve, which provides the control of airflow in and out of the air cylinder. The shaft provides a hammering strike to the tool driver near the end of its stroke. The high velocity found near the end of the stroke and the mass of the piston and shaft provide a powerful pulse strike to the tool driver (See FIG. 4). The tool driver is mounted on the frame in bushings that provide alignment with the air cylinder shaft and to control its translational movement. The tool driver is a lightweight structural member. The “Demolition Demon” uses a square tool driver shaft with square guide/bushings that allow translational movement and restrict rotational movement. The bulk of the “Demolition Demon's” weight is found near the upper end of the tool to provide the operator with better control and ease of handling the tool. The tool driver is prevented from rotating excessively by the guides mounted along the tool frame. The tool driver extends from the lower bushing at the lower end of the frame. Tools are attached to the tool driver by means of pinning. These tools include: nail removal shovel blade with integral fulcrum, flat bars, scrappers, wedges, punches, cutting blades, and specialty application tools such as guided prying wedges or cutting tools (i.e. a wedge with a channel shaped guide attached to the bottom of the wedge to guide it along a rafter when removing sheathing). The tool driver lower bushing is larger than the upper bushing in terms of opening and length. This is done to allow for inserting the tool mounting tube through the lower guide/bushing while inserting the tool driver and the tool mounting tube. This mounting method reduces the amount of bending that both the tool mounting tube and the tool driver experience individually during use. The insertion of the tool driver into the tool mounting tube effectively increases moment of inertia of the combined members to resist bending. The two members are then joined together on either sided of the bushing/guide by pinning. The pinning locations also serve as limits for transitional movement of the tool, tool driver, and the air cylinder piston.

The fame lower end is an open square tube tat can be used to insert and pin fixtures for use with the tools attached to the tool driver.



FIG. 1: Provides overall external view of nail/fastener removal tool “Demolition Demons” side view.

FIG. 2: Provides an overall external view of the nail/fastener removal tool “Demolition Demon” top view

FIG. 3: Provides a section view of the air cylinder (double acting, nose mounted) with one piece piston and shaft

FIG. 4: Is a graph illustrating the impact power associated with a high mass piston and shaft air cylinder versus a conventional air hammer.

FIGS. 5 Through 8: Samples of tools that may be attached using the common interface.


Description of the Preferred Embodiment

The preferred embodiment of the tool is a combination tool incorporating the following: D or T-handle (3) with integral trigger (2) and air inlet (1) mounted to a stiff frame with guides and mounting locations for other components of the system: a nose-mounted double-acting air-cylinder (6), a trigger (2), multi-port valve (4), tool driver (8), tool (15) and stops (11). The “T” or “D” handle allows the operator to push on the tool with the palm of his hand perpendicular to the motion rather than along the axis of the motion of the tool. The operator gains further control by grasping the tubular handle (26) that extends from the side of the frame (3). The air cylinder has a high mass piston/shaft (23 &18) single piece unit enclosed in the air cylinder. The top cap (17) of the air cylinder is mountable to the frame (3) and contains a threaded port (20) to allow for air delivery to the top of the piston (23). The bottom cap (18) contains a bushing (25) that provides support and alignment of the shaft The bottom cap (18) is mountable to the frame and has holes (24) to provide for exhaust and intake of air below the piston during its motion back and forth within the air cylinder (6). Both caps are sealed with o-rings (21) and are removable once detached from the stiff frame of the tool. The frame mounting provides secure mounting (13 &14) of the air cylinder caps to prevent them from blowing off under pressure. The use of commercially available air switch/pilot valve (2) and multi-port valve (4) provides air control for the air cylinder. The tool driver (9), which in operation is impacted by the end of the air cylinder shaft (8), is a structural member that transmits the impact to the tool (15). The tool driver is mounted in the frame using guides/bushings (10 &16) that limit rotation while allowing translational movement. The tool driver is hardened and has a solid end, in order to survive the impact of the air cylinder shaft. The tools (See FIGS. 5, 6, 7, &8) are mounted by attaching them to the tool driver by pinning There is a selection of tools available that may be interchanged by using a common interface mounting arrangement. The tools all have a mounting tube (12) that fits over/surrounds the tool driver, nests the tool driver, by having a slightly larger inside dimensions than the tool driver has outside dimensions. The tool mounting tube, while enclosing the bottom end of the tool driver provides the bearing surface within the bottom guide (10) on the frame, thereby allowing use of lighter members to provide adequate bending resistance when in use. The tools are pinned in place and the pins (11) also serve as stops to regulate the travel of the tool driver (9) and tool (15). The frame (3) while providing support and alignment of the components also provides a mounting position for fulcrums and engagement/holding fixtures that may be used with some of the tools. The main tube of the tool frame is tubular and as a result a fulcrum or engagement fixture (26) can be mounted to the frame by inserting and pinning (27) at the lower end of the frame, below the lower bushing/guide (16). The tubing connections from the trigger (2) are not shown as the tubing will be routed inside the frame/handle. The tubing (5) from the 4-port multi-port valve (5) will be covered by a shield to protect them from damage. There will also be a shield that encloses the air cylinder shaft (8) to shield the operator from getting his hand or clothing caught up in the impact between the air cylinder shaft (8) and the tool driver (9). The shield for the impact area will be a tube that is mounted between the lower cap bracket (14) and the upper tool driver bushing (10).


The “Demolition Demon” tool is attached to an air compressor by means of a hose. The air enters an air inlet connected to both the multi-port valve and the trigger/pilot valve. To operate the tool the user slides the tool into position to remove the nail, by attempting to get the blade of the tool close enough to engaging the underside of the head of the nail/fastener. The operator then squeezes the trigger. The air cylinder receives no air until the trigger is pulled. When the trigger is pulled the multi-port valve provides high pressure air to the top of the piston in the air cylinder, driving the piston rapidly down the cylinder. The air under the piston is driven out of port/ports in lower end cap of the air cylinder. The air cylinder shaft extends out and impacts the tool driver. The tool driver shaft has limits that establish the distance of travel required by the air cylinder shaft to make contact with the tool driver and also the amount of travel the tool driver can move forward with respect to the tool frame. The tool driver drives the attached tool blade under the fastener/fasteners. The operator now pushes down on the handle of the “Demolition Demon” extracting the nails/fasteners from the roof sheathing. When the operator releases the trigger, the air in the air cylinder is exhausted out the air inlet port of the Multi-port valve and the tool is free to return to the top of its travel as it engages a nail or resistance of some kind.

When using the scrapper, the same basic principle can be applied, when the scrapper gets stuck the air-cylinder can be fired. When using a specialty tool for demolition, such as a wedge that is guided along a rafter or floor joist to remove sheathing, the same manual controlled firing of the air-cylinder can be used. The advantages to having the bulk of the weight up by the handle and the weight at the lower end of the tool reduced to the extent possible is that the tool is less tiring to use and easier to manipulate. These are significant attributes to the operator who is doing a lot of shingle removal or anything that requires him to move the head of the tool frequently and for long periods of time.