Cutlery – Cutting tools – With blade moving means
Reexamination Certificate
2002-01-15
2003-09-09
Payer, Hwei-Siu (Department: 3724)
Cutlery
Cutting tools
With blade moving means
C030S283000, C030S138000, C030S293000, C030S347000
Reexamination Certificate
active
06615494
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention is directed to rotary defatting knives and, more particularly, to an improved rotary defatting knife and generally toroidal blades used therewith in which the blades are quickly and easily interchangeable, the drive shaft and blade are mounted on ball bearings and the combination of features acts to reduce vibrations and improve performance of the knife.
2. Description of the Prior Art
The meat packing and processing industry has become increasingly important as the world population continues to grow thereby increasing the need for meat and meat products. As a result of the increased demand for meat, the meat packing industry had to become more efficient in its meat processing and packing operations. Through the use of improved technology and “assembly-line” like operations, the meat industry has been able to increase the production of meat and meat products. However, the industry requires individuals to use some form of knife to remove bones and trim the excess fat from the meat. Accordingly, the meat packing industry has attempted to produce knives that allow the user to debone and trim meat faster, safer, and more economically; a long-felt-need which has yet to be fully addressed.
The prior art discloses knives that typically have a handle, a drive mechanism, and a blade. Although there are numerous types of powered knives which are used, one of the more commonly used types includes a circular blade which rotates at a high rate of speed, the blade being rotatably supported on a handle. These knives are used to remove and trim fat from the carcass by “planing” the knife over the area on the carcass which is being trimmed and the spinning of the blade cuts the tissue being contacted to remove a strip from the carcass. It has been found that these types of blades are very efficient at removing tissue from the carcass, but there are inherent problems with the use of these knives that have not been solved by the prior art.
As with any knife, eventually the cutting edge of the circular blade of the knife becomes dull. This is especially true in the meat packing industry as the knives are used to cut through tough skin and sinew of the carcass. When an ordinary knife edge becomes dull, the user would merely sharpen the blade of the knife. However, with a circular blade, the sharpening process is much more involved, and in the case of the types of circular blades used in the meat industry, it is often necessary to send the blade to the producing company for sharpening. Alternatively, the blade would be removed and replaced with a new blade. In the prior art, in order to change the blade, the knife would have to be replaced, as with the one-piece knife, or all the numerous screws or bolts would have to be removed. This invention solves the long-felt-need in the industry allowing the operator to change out a dull blade quickly and easily without unfastening large numbers of screws or bolts or replacing the entire knife.
In the case of the one-piece knife, the blade cannot be changed out at all. The blade, handle, and blade support ring are all one piece and therefore cannot be disassembled to change out the blade. The operator would have to use a new knife with a sharp blade to cut through the meat and fat of the carcass. While an operator can change knives relatively quickly, it is expensive to replace an entire knife for a sharp blade.
Another prior art reference embodies a knife that has a blade that is attached to the blade support ring via a plurality of screws or bolts. This embodiment allows the operator to change the dull blade but only after the entire blade support unit is unscrewed and disassembled and a new blade is reassembled with the knife. This procedure, while potentially less expensive than the above example, is time consuming. The operator must take the time to disassemble the entire knife, a process that can take anywhere from five minutes to twenty minutes, replace the blade, and reassemble the entire knife unit with the new blade intact. The increased demand for meat requires this process to occur more frequently resulting in more time that is wasted replacing blades then less time spent deboning and defatting meat. Therefore, there is a need for a knife that has a quick and easy interchangeable blade.
Another problem in the meat packing industry, not solved by the prior art, is the large amount of vibration and noise emitted by the rotary knives. The nature of the meat packing industry requires the blades to rotate at extremely high-speeds. To achieve the required speeds, knives of the prior art incorporate a drive mechanism consisting of a drive shaft and a gear which are composed of metal. The drive shaft would engage the gear and both the shaft and gear would spin to rotate the blade which is also made of metal along with the blade support ring. As a result, the metal-on-metal contact of the knife components operating at high-speeds would cause a high-pitched noise that could damage the eardrum and impair hearing. Additionally, the lack of a damper in the drive mechanism and high-speed operation causes severe vibration of the knife that could result in loss of control of the knife and injury to the user. There is therefore a need for a knife that has a quickly and easily replaceable blade assembly and which also reduces noise and vibration.
Therefore, an object of the present invention is to provide an improved boning and defatting rotary knife.
Another object of the present invention is to provide a knife that has an interchangeable blade assembly that allows the blade to be replaced quickly and easily.
Another object of the present invention is to provide an improved boning and defatting rotary knife that significantly reduces vibration and noise produced by the knife.
Finally, it is an object of the present invention to provide an improved boning and defatting rotary knife which is relatively simple to manufacture and is safe and efficient in use.
SUMMARY OF THE INVENTION
The present invention is directed to a boning and defatting knife having a blade support unit including a handle, a blade support ring connected to and extending from the handle and a drive shaft mounted on at least one of the handle and the blade support ring. The knife further includes a blade unit having a generally toroidal blade engaging and locking device having a drive means engaging section and a releasable fastening and locking section and a generally toroidal blade having an outer locking edge and an inner cutting edge. The releasable fastening and locking section of the blade engaging and locking device is operative to releasably receive and lock the outer locking edge of the blade thereon, whereby the blade is removable and replaceable and the blade unit is adapted to be removably and rotatably seated on the blade support ring with the drive device engaging the drive device engaging section of the blade unit such that the blade unit is rotated within the blade support ring by the drive device.
The present invention as thus described has many advantages over those devices found in the prior art. The blade engaging and locking device is designed to receive and secure the blade therewithin and also allow the operator to quickly and easily replace the blade. Furthermore, the construction materials used in connection with the blade engaging and locking device substantially reduce the high-pitched noise emitted from the knife during its operation, thereby decreasing the risk of hearing impairment. Additionally, the inclusion of ball bearings in the device reduces knife vibration during its operation. Finally, the combination of features found on the present invention render the invention far more efficient and safe for use than those devices found in the prior art. Therefore, the present invention is seen to provide substantial improvements over those devices found in the prior art.
REFERENCES:
patent: 4494311 (1985-01-01), McCullough
patent: 4854046 (1989-08-01), Decker et al.
patent: 4858321 (1989-08-01), McC
Long John W.
Ross Dale R.
Jacobs Adam H.
Payer Hwei-Siu
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