US3694918A

US3694918A - Metal-cutting apparatus

Info

Publication number: US3694918A
Application number: US190766A
Authority: US
Inventors: Darrel E Bailey; Earl M King
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-10-20
Filing date: 1971-10-20
Publication date: 1972-10-03
Anticipated expiration: 1989-10-03

Abstract

An apparatus for cutting sheet metal or the like under emergency conditions includes a bar having a pry surface and a cutting blade at one end thereof, and a cylinder reciprocably slidable thereon. In operation, the point of the cutting blade and the pry surface are rested on the sheet metal. The cylinder is extended, then slid in the direction of the point so as to drive the point through the sheet metal when the cylinder engages a corresponding stop on the bar. Cutting is then accomplished by rocking the bar, using the pry surface as a fulcrum.

Description

United States Patent Bailey et al.

[ 1 Oct. 3, 1972 [54] METAL-CUTTING APPARATUS [22] Filed: Oct. 20, 1971 [21] Appl. No.: 190,766

[52] US. Cl. ..30/277, 7/12, 173/126, 30/22 [51 Int. Cl ..B26b 27/00, B25d 17/02 [58] Field of Search....30/l6, 22, 277, 359, 168, 280, 30/314, 164.6; 7/12; 145/21, 30.5, 61 F;

[56] References Cited UNITED STATES PATENTS 584,189 6/1897 Nelson ..145/61 F 840,580 l/1907 McMillan ..145/61 F 1,174,785 3/1916 Watts... ..30/277 1,624,853 4/ 1 927 Winter ..30/168 1,667,360 4/1928 Sweeney ..30/314 2,285,386 6/1942 Atwood ..30/314 Primary Examiner-Robert C. Riordon Assistant ExaminerRoscoe V. Parker, Jr. Attorney-Christensen & Sanbom [5 7] ABSTRACT An apparatus for cutting sheet metal or the like under emergency conditions includes a bar having a pry surface and a cutting blade at one end thereof, and a cylinder reciprocably slidable thereon. In operation, the point of the cutting blade and the pry surface are rested on the sheet metal. The cylinder is extended, then slid in the direction of the point so as to drive the point through the sheet metal when the cylinder engages a corresponding stop on the bar. Cutting is then accomplished by rocking the bar, using the pry surface as a fulcrum.

7 Claims, 6 Drawing Figures METAL-CUTTING APPARATUS FIELD OF THE INVENTION This invention generally relates to apparatus for cutting sheet metal or the like and finds particular applicability in a device for freeing victims of vehicular accidents from a vehicle.

BACKGROUND OF THE INVENTION In vehicular accidents, it is often the case that access cannot be made to the interior of the vehicle through the vehicles doors or windows due to frame and body distortions. Because speedy access to the victims may often mean the difference between life and death, some means must be provided for cutting away the body sheet metal so as to create new access openings.

The prior art has almost exclusively relied on the use of a power saw for obtaining access. These saws suffer from serious disadvantages. First, their use causes a very loud, rasping noise as the cutting blade engages the sheet metal. This noise can be very disturbing to both the user thereof and any onlookers. Second, the cutting action of the saw creates sparks which are extremely hazardous in situations where gasoline is leaking. Third, the saw is relatively slow with respect to desired times of access to the victims.

It is therefore an object of this invention to provide a metal-cutting apparatus which is particularly useful in cutting sheet metal under emergency conditions.

It is a further object of this invention to provide a metal-cutting apparatus in which the cutting force is entirely obtained as a result of the application of manual force thereto.

It is yet another object of this invention to provide such a metal-cutting apparatus which is quiet and speedy in operation, and which does not create sparks as the result of the engagement of the apparatus thereof and sheet metal.

It is still a further object of this invention to provide such a metal-cutting apparatus which is readily adaptable to other metal-working operations, such as prying, bending, and the like.

SUMMARY OF THE INVENTION These objects and others are achieved in one embodiment of the invention by the provision of an elongated bar having a cutting blade and a pry surface at one end thereof and additionally having stop means thereon, and an impact member reciprocable with said bar, including means for engaging said stop means thereof.

BRIEF DESCRIPTION OF THE DRAWINGS The invention can perhaps be best understood by reference to the following portion of the specification, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a pictorial view showing the use of the metal-cutting apparatus of this invention;

FIGS. 2 and 3 are side elevation views showing the preferred embodiments of the invention, with the impact member in extended and retracted positions, respectively;

FIG. 4 is a front elevation view showing a portion of the apparatus; and

FIGS. 5 and 6 are side elevation views showing alternate, interchangeable metal-working bars for use with the apparatus in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference now to FIG. 1, the metal-cutting apparatus16 of this invention is shown in use. In the illustrated situation, access is desired through the roof 10 of a vehicle. In this case, the user of the apparatus 16 has created an initial opening 12 in the roof 10, then has proceeded to cut the roof 10 along the line 14. Both the initial opening 12 and the cut 14 are produced by appropriate manipulation of the apparatus 16, in a manner to be described in more detail hereinafter.

With reference now to the embodiment shown in FIGS. 2, 3 and 4, the apparatus 16 includes an elongated bar 18 which is preferably composed of solid steel stock. The bar 18 has pry surfaces 20a, 20b at one end thereof. A cutting blade 22 is welded or otherwise afiixed to the bar 18 and includes a first cutting surface 24a which extends from the bar 18 to a second, rightangle cutting surface 24b which preferably extends along blade 22 in a direction parallel to the axis of bar 18. Cutting blade 22 also includes a third cutting surface 240 which extends from cutting surface 24b to a termination point 26 of blade 22. As can be seen, termination point 26 is separated from but substantially coplanar with pry surfaces 20a, 20b. Preferably, cutting blade 22 is composed of a hardened carbon steel.

The apparatus also includes a metallic cylinder 28 which is reciprocably slidable on bar 18. In detail, the upper end of cylinder 28 is terminated by a member 30 which is in threaded engagement therewith and which defines an aperture 32 for guiding the reltive reciprocation of bar 18. The extension of bar 18 is limited by the engagement of the inner surface of member 30 and a corresponding enlarged portion 34 of bar 18. As the diameter of enlarged portion 34 is chosen to roughly approximate the interior diameter of cylinder 28, enlarged portion 34 additionally serves as a first guide means for reciprocation.

The other end of cylinder 28 is closed by a solid steel slug 38 which is welded into place. The retraction of bar 18 is limited by the engagement of slug 38 and a corresponding, enlarged diameter stop 36 on the end of bar 18. Because of its increased diameter, portion 36 additionally functions as a second guide means for reciprocation.

In operation, the pry surface 20a and point 26 are brought to bear against the sheet metal surface which is to be cut. The cylinder 28 is then slid so that the bar 18 is extended. When the extension is limited by the engagement of portion 34 and the corresponding member 30, the user pushes the cylinder 28 at a high rate towards the sheet metal surface. When the slug 38 therein impacts the corresponding enlarged diameter portion 36, the impulse resulting from the momentum of cylinder 28 is transferred through the bar 18 to pry surface 20a and point 26. This impulse usually drives the point 26 through the sheet metal and further serves to enlarge the hole, such as the aperture 12 in FIG. 1, by cutting action of the surface 240. It has been found in practice that no more than two or three impulses are required to drive the point 26 through a sheet metal surface.

To cut along the line 14, the user then rocks the apparatus 16 by using the pry surface 20a as a fulcrum and the bar 18 and cylinder 28 as a lever. As a result of this rocking motion, the sheet metal is cut by the cutting surfaces 24a and 24b.

If the apparatus is appropriately dimensioned, the use thereof employs a large mechanical advantage in transmitting the rocking motion exerted by the user into a cutting action such that practically any sheet metal surface can be rapidly cut with a minimum of effort. In a practical embodiment, the bar 18 was about 3 feet long from end to end and comprised a 1 inch diameter bar of solid steel stock. The cylinder 28 comprised a section of 2 inch steel pipe, approximately 2 /2 feet long. Finally, the cutting blade 22 was fashioned from an automobile leaf spring and was approximately inches long. The enlarged diameter portion 34 was formed by welding a machined bushing onto shaft 18, and the enlarged diameter 36 was formed by appropriate heat treatment thereof.

The metal-cutting apparatus 16 is also useful for cutting through vehicle door pillars and other more substantial metal surfaces. ln this regard, both the pry surfaces a and 20b are useful in exerting a prying force between a jammed door and its pillar or frame, between the trunk and surrounding sheet metal, or other corresponding surfaces.

The design illustrated is also applicable for receiving tools for other metal-working operations. With particular reference to FIG. 5, a bar 18' includes enlarged portions 34', 36, which are of similar construction to the

enlarged portions

34, 36 of the bar 18. The bar 18' is reciprocable within a coupling member and includes at the upper end thereof a flared cutting blade 40 having a cutting surface 42 on each side thereof. The bar 18 is installed in the cylinder 28 by unscrewing the coupling member 30 associated with bar 18, removing bar 18, inserting bar 18' and screwing coupling member 30 onto the corresponding threaded portion of cylinder 28. The bar 18' is particularly useful for making narrow cuts through relatively thick sheet metal surfaces.

Bar 18", useful for prying and bending operations, is illustrated in FIG. 6 and includes enlarged portions 34' 36", a coupling member 30, and two pry surfaces 44 on either side of one end thereof. Bar 18" is inserted into the cylinder 28 in a manner identical to

bars

18 and 18.

Although the invention has been described particularly in terms of a metal-cutting apparatus for use in obtaining access to vehicles of a emergency conditions, it should be clearly understood by those skilled in the art that the invention is not limited thereto. For example, the invention finds applicability in any situation where a rough, speedy cut of sheet metal or other like material is required. Therefore, the limits of the invention are intended to be bounded only by those of the appended claims.

We claim:

1. A metal-cutting apparatus comprising:

a. an elongated bar having a pry surface at a first end thereof and including a stop means adjacent a second end thereof,

b. a cutting blade affixed to said elongated bar adjacent said first end thereof, said cutting blade havingja cutting surface separated from but extendgig su stantially parallel to and facing said bar, an a point adjacent said cutting surface which is substantially co-planar with said pry surface of said bar, and

c. an impact member reciprocal with said elongated bar which includes means for engaging said stop means at some point in reciprocation to thereby transmit an impulse to said elongated bar.

2. An apparatus as recited in claim 1, wherein said cutting blade includes a second cutting surface extending from said first cutting surface to said point thereof.

3. An apparatus as recited in claim 2, wherein said cutting blade includes a third cutting surface extending substantially at a right angle from said cutting surface to said bar.

4. An apparatus as recited in claim 1, wherein said impact member comprises a hollow member slidable on said bar, and wherein said engaging means of said impact member comprises a solid member closing a lower end of said hollow member, and said stop means on said bar comprises said second end thereof.

5. An apparatus as recited in claim 4, wherein said bar further includes an enlarged portion thereof between said first and second ends, and said impact member further includes a coupling member for closing the upper end of said hollow member, said coupling member defining an aperture therein for the passage of said bar and including means for engaging said enlarged portion thereof so as to limit the extension of said bar relative to said said impact member.

6. An apparatus as recited in claim 5, wherein said bar, said hollow member, said stop means, said engaging means and said coupling member are substantially cylindrical.

7. An apparatus as recited in claim 1, wherein said cutting blade is composed of a sheet of spring steel which is relatively thin with respect to the thickness of said bar.

Claims

1. A metal-cutting apparatus comprising: a. an elongated bar having a pry surface at a first end thereof and including a stop means adjacent a second end thereof, b. a cutting blade affixed to said elongated bar adjacent said first end thereof, said cutting blade having a cutting surface separated from but extending substantially parallel to and facing said bar, and a point adjacent said cutting surface which is substantially co-planar with said pry surface of said bar, and c. an impact member reciprocal with said elongated bar which includes means for engaging said stop means at some point in reciprocation to thereby transmit an impulse to said elongated bar.