Patent Application
20110259073
1. Field Of The Invention
This invention relates generally to the field of metal-working tools and relates more particularly to a compound leverage hand seamer having removable blades.
2. Description Of The Related Art
Hand seamers, also known as hand brakes, are portable hand tools that are used for bending and flattening sheet metal such as flashing for roof and window applications. Conventional hand seamers are constructed from two levers that are pivotably connected to one another at a point intermediate their ends. A first end of each lever terminates in a substantially planar, rectangular blade. A second end of each lever defines an elongated handle, sometimes also referred to as a hand grip. By moving the handles of the seamer toward one another, a user causes the blades of the seamer to pivotably move toward one another and ultimately clamp together in a flatly abutting relationship. Modern hand seamers commonly incorporate a conventional compound leverage handle configuration for allowing the blades of a seamer to be clamped firmly together by applying relatively less force to the handles as compared to traditional, non-compound leverage hand seamers.
To use a conventional hand seamer, a user firmly clamps an area of sheet metal flatly between the blades of the seamer. The user then manually rotates the seamer to bend the clamped portion of metal to a desired angle relative to the surrounding sheet metal, causing the metal to be folded along a line defined by the top edges of the clamped blades. The hand seamer thereby allows a user to create clean, straight fold lines in sheet metal which is otherwise difficult to manipulate by hand. A hand seamer can be employed in a similar manner to grip and flatten, or unbend, a segment of bent sheet metal.
A problem commonly associated with both traditional and compound leverage hand seamers is that the blades of such seamers are integral with, and are not removable from, the rest of the tool. Therefore, if the blades are damaged in such a way that renders them ineffective or unusable, such as by being severely scratched, dented or cracked, the entire tool must be disposed of and replaced.
Another problem commonly associated with existing hand seamers is that the blades of a particular hand seamer are of a predetermined, fixed size that cannot be easily modified by a user. Hand seamers are thus typically offered in a variety of different blade sizes (e.g. 3″×1″, 6″×2″, 9″×1″, etc) for accommodating different size applications. A particular hand seamer is therefore generally only appropriate for handling a particular size of job. For example, if a user needs to bend or flatten an immovable piece of sheet metal that is located in an area having only three inches of surrounding clearance, a user would not be able to use a hand seamer having 6″ long blades for the task. Conversely, if a user needs to create a 6″ long bend in a piece of sheet metal, a hand seamer having 3″ long blades would not be as appropriate for the task as a hand seamer having 6″ long blades. Frequent users of hand seamers are therefore required to purchase, store, and maintain several different sizes of hand seamers to ensure preparedness for various different tasks. This can be costly and burdensome.
It is therefore an object and feature of the present invention to provide a hand seamer with blades that can be easily replaced independently from the rest of the tool when one or both of the blades become ineffective or unusable.
It is a further object and feature of the present invention to provide such a hand seamer with interchangeable blades of various different sizes for accommodating a variety of different tasks without requiring a user to purchase and maintain several different tools.
In accordance with the present invention, there is provided an improved compound leverage hand seamer with removable blades. The hand seamer includes a pair of pivotably connected handles and a pair of pivotably connected seamer heads. Each of the seamer heads is connected to one of the handles at a first end and terminates at a second end in a substantially planar head segment having a flat, inwardly-facing mounting surface. A substantially planar, rectangular blade is removably mounted to the mounting surface of each of the seamer heads in a flatly abutting relationship therewith, preferably by a pair of threaded fasteners that engage mounting holes in the seamer heads and in the blades. By forcibly moving the handles of the seamer toward one another, the blades can be firmly clamped together. The improved hand seamer can thereby be used in the manner of a conventional hand seamer for griping and bending sheet metal.
If one or both of the blades of the improved hand seamer become worn or damaged over the course of use, the fasteners that hold the blades to the seamer heads can be removed, such as with a conventional screwdriver, and the blades can be replaced with a new set of similar blades. Therefore, unlike traditional hand seamers having non-removable blades, a damaged blade does not render the entire tool useless or ineffective. Similarly, if a user of the improved hand seamer encounters a task that requires smaller or larger blades than the blades that are currently mounted to the seamer heads, the existing blades can be removed from the seamer heads and a set of blades of a more appropriate size can be installed. The user of the hand seamer therefore does not have to own and maintain multiple, different-sized hand seamers for performing different-sized tasks.
Additional blades are preferably provided for the improved hand seamer in incremental lengths of 1 inch and incremental widths of 0.5 inches, and preferably range from a shortest length of 3 inches to a longest length of 9 inches and a narrowest width of 1 inch to a widest width of 5 inches. Such additional blades can be provided with the improved hand seamer as part of a set or can be sold to consumers separately.
In describing the preferred embodiment of the invention which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific term so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
Referring to
Referring to
The seamer heads 20 and 22 of the hand seamer 10 are similar to the seamer heads of conventional compound leverage hand seamers insofar as they are generally T-shaped with elongated neck segments 28 and 30. The neck segments 28 and 30 are pivotably connected to the handles 12 and 14 by pivot pins 32 and 34 at a first end and terminate in perpendicular head segments 36 and 38 at a second end. The neck segments 28 and 30 of the seamer heads 20 and 22 are pivotably connected to one another in a conventional manner by a main pivot pin 40 that passes transversely through a pair of laterally-aligned connecting lobes 42 and 44 that extend inwardly from each of the neck segments 28 and 30. This configuration allows the neck segments 28 and 30 of the seamer heads 20 and 22 to be pivoted relative to one another about the axis of the main pivot 40 pin without intersecting or colliding with each other. The hand seamer 10 thereby operates in the manner of conventional compound leverage hand seamers, with forcible movement of the hand grips 16 and 18 toward one another causing the head segments 36 and 38 of the hand seamer 10 to pivotably move toward one another.
Referring now to
The blade 26 is a substantially planar, rectangular plate that is preferably formed of conventional steel of the type used to fabricate common hand tools, although it is contemplated that the blade 26 can be formed of any other suitably rigid and durable material, including, but not limited to high carbon steel and titanium. Importantly, the blade 26 should be rigid enough to be able create a clean, straight fold line in a piece of sheet metal (as described below), but resilient enough to resist chipping and cracking when placed under force in the course of normal use. The blade 26 has an outwardly-facing mating surface 52 and an opposing, inwardly-facing engagement surface 54. The engagement surface 54 of the blade is preferably textured with a plurality of narrow, wave-shaped grooves (not shown) for providing a tread-like, frictional surface for securely gripping sheet metal. It is contemplated that the engagement surface 64 of blade can incorporate a variety of alternative textured groove patterns for achieving a similar purpose, such as a diamond-shaped pattern, a concentric circle pattern or a zig-zag pattern. Any such alternative surface patterns should not, however, incorporate sharp projections or other features that could cause damage to a segment of sheet metal being gripped by the hand seamer 10.
Two laterally-spaced, threaded mounting holes 56 and 58 extend through the blade 26 in a perpendicular relationship with the mounting and engagement surfaces 52 and 54. The mounting holes 56 and 58 are preferably equidistant from the lateral center of the blade 26. The on-center distance between the mounting holes 56 and 58 is equal to the on-center distance between the mounting holes 44 and 46 in the head segment 38, and the radii of the mounting holes 56 and 58 are preferably equal to the radii of the mounting holes 44 and 46 in the head segment 38. An alternative embodiment of the invention is contemplated in which the mounting holes 56 and 58 extend from the mating surface 52 only partially through the blade 26, thereby leaving the engagement surface 54 of the blade 26 continuous and unbroken.
Still referring to
It is contemplated that direction of the fasteners 48 and 50 can be reversed, with the fasteners 48 and 50 being inserted through the engagement surface 54 of the blade 26 instead of through the outwardly-facing surface of the head segment 38. In such a configuration, annular recesses are preferably formed in the engagement surface 54 surrounding the mounting holes 56 and 58 for matingly accepting the fastener heads in the manner described above, thereby preventing the fastener heads from protruding from the engagement surface 54 of the blade 26 and possibly damaging sheet metal gripped by the hand seamer 10. It is further contemplated that a greater or fewer number of removable fasteners can be used to secure the blade 26 to the seamer head 22 in the manner described above, with a commensurate number of threaded mounting holes formed through the blade 26 and the through head segment 38.
The assembled hand seamer 10 is operated in substantially the same manner as a conventional compound leverage hand seamer, with the seamer heads 20 and 22 being pivotably movable between a closed position (shown in
The blades illustrated in
Additional blades are preferably provided in incremental lengths of 1 inch (e.g. 3 in, 4 in, 5 in, 6 in etc.) and incremental widths of 0.5 inches (e.g. 1 in, 1.5 in, 2 in etc.), and preferably range from a shortest length of 3 inches to a longest length of 9 inches and a narrowest width of 1 inch to a widest width of 5 inches. For example, a pair of 6 inch long, 1 inch wide blades 200 and 202 is shown installed on the hand seamer 10 in
This detailed description in connection with the drawings is intended principally as a description of the presently preferred embodiments of the invention, and is not intended to represent the only form in which the present invention may be constructed or utilized. The description sets forth the designs, functions, means, and methods of implementing the invention in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and features may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention and that various modifications may be adopted without departing from the invention or scope of the following claims.
