Patent Application
20070006469
The present invention relates to cutting devices for cutting various types of material such as thin vinyl, plastic, paper, cardboard, or string. In particular, the present invention is directed to the art of hand-held cutting devices and cutting devices capable of being supported by at least one human finger.
Generally, finger mounted cutting devices exist in the art. However, these devices have a number of limitations. One limitation involves the breadth of material that prior art cutters can cut. In most cases, the prior art cutters are capable of cutting only a limited range of materials (e.g. grape stems or envelopes). Another limitation involves the ergonomic and safety aspects of the prior art cutters. Many prior art devices use an exposed fixed blade design which can lead to severe cuts if the user is not extremely careful at all times. In addition, other prior art devices attach to the user's hand in a manner that may result in fatigue and discomfort after extended use. Further limitations of the prior art cutters involve their ability to make straight, smooth, and consistent cuts.
For the reasons discussed above, it is the objective of the present invention to provide certain improvements in the art of hand-held cutting devices.
The present invention sets forth multiple novel improvements to the art of cutting devices that slide over or are supported by a human finger. These improvements primarily involve the safety, convenience, accuracy, and speed with which various types of material may be cut. The cutter invention described herein is a device that is comfortable to hold, simple to use, and capable of making quick and accurate cuts.
In one embodiment, the cutter device invention includes a generally cylindrical inner sleeve slideably engaged with a generally cylindrical outer sleeve, where each sleeve includes an open end and a closed end. The open end of the inner sleeve is adapted to fit over a human finger. The inner sleeve has an extended position and a retracted position with respect to the outer sleeve. A blade for cutting various materials is attached to the closed end of the inner sleeve. When the inner sleeve is in the extended position, the blade protrudes through a slot in the closed end of the outer sleeve thus permitting the user to bring the blade into contact with the material to be cut. A button is formed from the inner sleeve material resembling a tab and is bent slightly in an outward radial direction. A button aperture is disposed along the outer sleeve such that when the inner sleeve is in the extended position, the button is aligned with and engages the button aperture. A biasing element is confined between the sleeves and is disposed about the blade. When the button is pushed inward it disengages from the button aperture and the biasing element urges the inner sleeve into the retracted position. The inner sleeve further includes a pair of retaining ribs which project radially outward and engage a pair of retaining rib apertures in the outer sleeve. The retaining ribs prevent the inner sleeve from becoming disengaged with the outer sleeve. Lastly, the closed end of the outer sleeve includes a plurality of flat guide surfaces and a straight guide groove. A pair of the flat guide surfaces intersect at about a 90° angle to permit the cutter device to accurately cut material along an inside corner of an object. A large flat guide surface serves to maintain the blade at a fixed angle with the material to be cut permitting the user to make smooth straight cuts. Finally, the straight guide groove permits the user of the cutter device to make straight and accurate cuts along the edge of a support surface by gliding the straight guide groove along the edge of the support surface.
In another embodiment, one of the flat guide surfaces includes a guide rib which projects perpendicularly outward from a flat guide surface and extends linearly outward from the slot on the closed end of the outer sleeve. The guide rib provides a guide surface for guiding the cutter device along edges where a straight guide groove would not be as effective. For example, a sharp support edge is ideal for use with the straight guide groove whereas a corner with a large bend radius is not. The guide rib is particularly suited for such circumstances.
In yet another embodiment, a pair of straight guide grooves are disposed in an offset fashion on either side of the slot. The straight guide grooves extend linearly outward along one of the flat guide surfaces. Each straight guide groove operates in a similar fashion as discussed previously, however, the offset of the present embodiment permits the cutter device to cut the material just to the left or right of the edge of the support surface.
The following figures and description explain in greater detail the principles by which the novel improvements enhance the operation of the cutter device invention.
With reference to
The inner sleeve 130 generally includes an open end 132, a closed end 134, a button 136 and at least one retaining rib 138. The blade 140 is disposed on the closed end 134 of the inner sleeve 130. The blade 140 includes a sharp end 142 and a shank end 144. The sharp end 142 is intended to serve as the cutting edge for the cutter device 100. The shank end 144 provides a surface by which to attach the blade 140 to the inner sleeve 130. The button 136 of the inner sleeve 130 can be formed out of the same material of the inner sleeve by cutting a portion of the inner sleeve such as to form a tab. The button 136 is bent slightly outward such that when the inner sleeve 130 is inserted into the outer sleeve 110, the button 136 will elastically deflect inward and exert pressure between the button surface and the inner wall surface of the outer sleeve 110.
Prior to being assembled, the biasing element 150 (e.g. a compression spring), is placed over the blade 140 before the inner sleeve 130 is inserted into the outer sleeve 110. Once the inner sleeve 130 is inserted into the outer sleeve 110, a retaining rib 138 is punched outwardly through the retaining rib aperture 116. The retaining rib 138 may be punched out of the inner sleeve material itself or a pin may be inserted through the retaining rib aperture 116 once the inner sleeve 130 has been inserted into the outer sleeve 110. The inner sleeve 130 is sized appropriately such that it is slidably engageable with the outer sleeve 110. In addition, the open end 132 of the inner sleeve 130 is sized such that it will easily fit over an average sized human index finger. Once the cutter device 100 is fully assembled, the inner sleeve has two positions, an extended position and a retracted position. When the inner sleeve 130 is in the extended position, the blade 140 protrudes through the slot 112 in the outer sleeve 110 (as shown in
Now with reference to
In particular, the large flat guide surface 122c of the closed end 120 facilitates in keeping the blade 140 in perpendicular alignment with the material being cut. The consistent alignment of the blade 140 with respect to the material while cutting further ensures a uniform and smooth cut. The cutter device 100 may also be used to cut material that is present on an inside corner edge of a compartment, such as a drawer. The flat guide surfaces 122a and the flat guide surface 122b intersect at about a 90° angle. The intersection of the flat guide surfaces 122a, 122b at about the 90° angle facilitate the cutting of material along an inside corner. For example, when placing shelf liner material inside a drawer, the user would place the cutter device 100 with the 90° intersecting surfaces 122a, 122b in towards the inside corner edge of the drawer. The user would then glide the cutter device 100 along the inside corner edge cutting the shelf liner material accurately and smoothly in one pass.
It should be noted that the intersection angle need not be precisely 90 degrees. The intersection angle may vary by several degrees. Such minor variation will not adversely impact the operation of any embodiment of the cutter device discussed herein. Furthermore, although the first embodiment 100 and subsequent embodiments describe a cutter device with an inner sleeve adapted to fit over a human finger, all of these embodiments may be grasped or held between the fingers of a human hand. For instance, the embodiments described herein may be held like a pencil or a pen by gripping the cutter device between the thumb, index finger, and middle finger. Alternatively, the user may simply slide the cutter device over one available finger to free the remaining fingers for other tasks. Depending on the specific cutting application, the user may prefer supporting the cutter between the fingers or over a single finger.
Now with reference to
Now with reference to
Now with reference to
Now with reference to
With reference to
The above detailed description has set forth exemplary embodiments of the present invention in addition to what the inventor(s) have contemplated as being the preferred embodiment. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the exemplary embodiments be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
