Patent Application
20150328790
The invention relates to a method of using a knife, which knife has a knife handle, a knife blade extending in elongation of the knife handle, safety means including at least one strap having a strap opening, and the at least one strap is secured to or at a free end of the knife handle.
There exist many different knifes. Some are dangerous to use and some propose means to enhance safety during use, but suggestions to new and safer methods for using sharp knives are very limited.
From Chinese utility model no. CN 2753531 is known a single-ring knife handle, which can enhance user safety. A firm single-ring finger buckle ring, which is suitable for a forefinger to be conveniently buckled in, is arranged between the lower position of the front part of the existing knife handle and a knife body. When the single-ring knife handle is held in hand, the forefinger is passed through the finger buckle ring, so that the knife handle can be held more firmly when a knife is used and the fingers be protected. The buckle ring is however situated in the same plane as the knife edge close to said knife edge and there still remains a risk that other fingers can reach the knife edge. Moreover, the user has little freedom to arrange his hand or palm on the knife handle due to the fixed position of the rigid buckle ring close to the cutting edge.
From Chinese utility model no. CN 201208751 is known another knife including a knife handle in fixed connection with the knife body. A safety device is arranged on the knife handle, extends at two ends of the knife handle, and includes a first hand protecting part and a second hand protecting part. The first hand protecting part is formed by extending and bending the knife handle at an end connected with the knife body, and the second hand protecting part is formed by extending the knife handle at an end far from the knife body and in the same direction as the first hand protecting part. This known safety device is provided on the knife in a manner that compromises the utility of the knife. The user has reduced contact with the knife handle and maneuvering is cramped.
Old U.S. Pat. No. 998,046 from 1911 proposes an alternative way of using a broom-corn cutting knife with a handle. Thus U.S. Pat. No. 998,046 relates to knives for cutting the heads from broom-corn in order to relieve the operators hand from undue strain and enable use of the knife for extended period without the hand becomes cramped and chafed. Instead of holding the knife by it's handle it is suggested to hold around the knife blade during cutting. The knife has a guard that overlies a dull upper edge of the knife blade and provides a seat for the hollow of the hand. A leather loop is secured halfway up the knife handle and lies underneath the heel of the knife blade. This known knife is not safe to use. As also illustrated in the patent document a substantial length of the leather loop extends opposite and parallel to the guard and below the cutting edge. The particular postion and length of the loop are required to enable the operator to use both the leather loop and the guard at the same time. However, when the operator positions the guard in the hollow of the hand and passing his/her fingers through the loop he will inevitable cut his/her fingers when using the knife, e.g. when using maximum force as dictated by U.S. Pat. No. 998,046. If the loop is made shorter the operator is unable to reach the guard. Accordingly, U.S. Pat. No. 998,046 does not provide a safety knife nor a safe method of using a knife. Moreover, only a short length of the cutting edge is available for cutting so that the operator can only make limited use of cutting edge.
US2005/144790 relates to a training knife for use by e.g. military. One end portion of an elongated lanyard is separably attached to the free end of the handle of the knife, and the other end portion of the lanyard can be provided with a loop, which is size-adjustable due to the provision of a slip knot. The loop surrounds the wrist of one hand of the person using the knife so that the knife always is at hand in case it's use is needed. The loop is tightened around the wrist so that the operator don't loose the knife, and the knife will hang freely from the hand as long as the knife is not used. The lanyard is long and has a length between it's end portions in the range of between about 8 inches and 15 inches. The slip knot makes the loop variable, and this known knife just suggests an alternative to having the knife hanging from the belt. It cannot serve as a safety knife because the long lanyard cannot prevent the operator from accidental contact with the cutting edge during use. The long lanyard may even be in the way if e.g. the knife is used in a slaugterhouse.
US 2003/0208910 relates to a combination knife having at least five cutting surfaces, which the operator accidentally can hurt himself/herselve on. The combination knife has two very sharp gut hooks, one of which is located close to a forefinger grip aperture. Optionally the combination knife has a looped cord for hanging the knife on a belt. No means to reduce the risk of cutting accidents when using this dangerous knife are suggested or hinted to.
In case a known safety knife has an eye for inserting a finger in order to obtain improved control of said knife during it's use, such eye is located close to the knife blade and cannot serve to prevent the operator from grasping around the knife blade or from accidental forward movement of the hand towards the knife blade.
A slaughterhouse worker must work fast and precisely when hand-cutting carcasses. The worker uses an extremely sharp knife in one hand and a safety glove, such as a chain nail glove, on the other hand. Thus, when operating the knife, the other hand is well protected by the glove from being accidentally cut by the knife in case the knife slips or is otherwise misdirected. The hand that holds the knife gets wet and the knife handle slippery due to fat residues and humidity from the carcass thereby increasing the risk of the fingers slipping on the knife handle.
The aim of the present invention is to improve safety of using sharp knives, in particular to provide an improved method for using a sharp knife and a means for eliminating or at least minimizing cutting injuries in butcheries and slaugterhouses.
To this aspect the present invention provides a novel method of using a knife safely, a safety means for use in the method, which safety means and method can be implemented on commercially available knives.
In a second aspect according to the present invention is provided a safety means for a knife handle and a method that allows the operator freedom to arrange his hand in a convenient position around the knife handle without compromising safety during operating the knife.
In a third aspect according to the present invention is provided an elongated knife with a means for improved operator safety, which knife complies with standard sanitary regulations and guidelines for use in slaugterhouses.
In a fourth aspect according to the present invention is provided a method of using an elongated knife with a safety means wherein the risk of self-hurting or accidentally hurting others is eliminated.
In a fifth aspect according to the present invention is provided a method of using an elongated knife with a safety means wherein the method eliminates or at least reduces number of events of accidental contact with the knife blade.
The novel and unique whereby these and other aspects are achieved according to the present invention consists in the fact that the method comprises the steps of
Within the context of the present invention the term “knife handle” means the part of the elongated knife extending opposite the knife blade in elongation of said knife blade. In some embodiments the knife blade can have an extension serving for securing said knife blade to the knife handle. The extension is embedded in the knife handle and may protrude outside the knife handle at the free end. It is to be understood that any protrusion in extension of the knife handle is part of the knife handle.
Within the context of the present invention the term “the free end of the knife handle” means the free end of the elongated knife closest to the operator during use, thus the part of the knife handle opposite the transition to the knife blade. The phrase “secured to the free end” or “secured at the free end” means securing in elongation of the knife handle as well as securing to the sides of the knife handle in proximity or directly to the free end.
Within the context of the present invention the term “strap” means a loop or a bent band or strip having two legs extending opposite each other and defining an opening, the “strap opening”, for inserting an object, a finger, in a selected position.
When grasping the knife handle the operator arranges at least one finger through the strap opening of the at least one strap and subsequently places both this finger as well as the other fingers around the handle and at least one finger around a part of the strap. When closing the fingers around the knife handle the at least one strap is stretched out.
The size of the at least one strap, and thus the strap opening and the length of the strap, when the strap is stretched as long as it can, should be adapted to the individual operator and the specific knife. When an operator implements the method consideration needs to be made to arbitrary variables such as e.g. hand sizes, finger thicknesses, finger lengths, knife handle, including length, thickness and shape of knife handle. These variables, correlations and choices need to be made from case to case and have individual character. Thus size of the at least one strap, including size of strap opening and ultimate length of strap legs, are to be selected and/or adjusted to fit the operator in view of the knife handle too, as emphasized by the method according to the present invention. It is important that just the right strap for a certain operator's use of a certain knife is selected. So the method is closely related to a specific operator's anatomy in view of a certain knife. The strap opening is e.g. sized so that in the first position and/or the second position it fits narrowly around the middle part of the inserted finger and is fixed in this position. If the operator has selected a longer strap, the strap may only be so long that the operator is unable to reach the knife blade with the palm of the hand. The strap may engage both around the inserted finger and be catch by the interstitial web between two adjacent fingers. The end of the at least one strap opposite the end, which is secured to the knife handle, may thus hit the skin in the gap between the inserted finger and the neighboring finger, or if more than one finger is inserted, any corresponding gaps, thereby defining and setting a reachable foremost position of the hand in relation to the knife blade in the second position of the at least one strap. This reachable foremost position is a.o. defined by the length of the at least one strap when stretched out, and cannot be made longer or shorter without replacing the at least one strap with another strap. Thus, the at least one strap effectively prevents further forward movement of the hand in relation to the knife handle while performing a cutting action while the finger is kept inserted through the strap opening.
Which size of strap that suits the operator the best is an individual choice and the operator's choice may even differ from task to task provided the conditions mentioned above are not deviated from. Because the at least one strap is fixed to the free end of the knife handle only, the at least one strap can be moved around the longitudinal axis of the knife handle attached to and engaging at least a portion the selected finger, so in the second position the arrangement of the hand on the knife handle and the specific orientation of the inserted finger may also vary. Thus, although at least one finger of the operating hand of the operator is secured in the at least one strap, the operator is still able to position said hand in numerous convenient and ergonomical positions on the knife handle. So, contrary to known safety knives, e.g. the prior art safety knives discussed above, the operator has a great freedom to shift angular hand position on the knife handle during use if e.g. one hand position is convenient for one task and another hand position is better for another task. Accordingly, the at least one strap is secured to or at the free end of the knife handle and can expediently follow the hand during repositioning on the knife handle. Improved cutting safety is obtained by the fact that the at least one strap effectively prevents accidental axial displacement of the hand towards the knife blade. Forward movement is simply stopped. Moving the hand towards the knife blade can simply not take place while the inserted finger is trapped in the strap opening. So the inserted finger, and thus the hand's position, is fixed by the at least one strap, due to the finger engaging the strap, often tightly because the size of the strap opening is selected to fit closely around the inserted finger, e.g. close to the root of the finger or at the middle part of the finger. The risk of the hand slipping on the knife handle out on the knife blade is eliminated or at least minimal.
The method may comprise that a major part of one leg of the stretched at least one strap is held lengthwise the knife handle during performing the cutting action. In the second position the operating hand is placed on the knife handle, and when a finger, which has been inserted through the strap opening, is used for locking the at least one strap to the operating hand, the free loop part of the at least one strap opposite the part of the at least one strap that is secured to or at the free end of the knife handle is caught by said inserted finger or the skin, the interstitial tissue, in the gap between the two adjacent fingers, thereby preventing further movement of said operating hand towards the knife blade. Accidents taking place in e.g. slaughterhouses when the knife handle gets slippery are eliminated. The same applies if more fingers are arranged through the at least one strap.
The most preferred finger to be arranged through the strap opening of the at least one strap is the thumb.
In a preferred embodiment suited for most hand sizes the at least one strap extends about half the length of the knife handle or less when stretched out lengthwise the knife handle. This length is given solely as an example. Since hand sizes and length of knife handles vary no specific limitation to dimensions of strap opening and length of knife handle are appropriate.
In order not to unduly limit the scope of the claimed method the method of the present invention is defined by interrelated factors associated to operator and knife. For example a large hand may require a short strap to avoid that the fingers or hand palm get too close to the knife blade. So it may be preferred that the at least one strap is resizable and/or is detachably secured to the free end of the knife handle. In the non-detachable or detachable embodiment the at least one strap can advantageously be configured or reconfigured on any of the sides of the knife handle to fit either left-handed or right-handed operators. The at least one strap can also be replaced. The at least one strap may e.g. be made in various standard sizes to be used by operators of different hand sizes. Alternatively, the at least one strap can be non-detachable, in which case a selection of safety knives of different strap lengths are intended.
Numerous ways of securing the at least one strap to the free end of the knife handle are intended within the scope of the present invention. The knife handle or an elongation of the knife handle may be provided with a first securing means for securing the at least one strap to or at the free end of said knife handle, and optionally a second securing means may be provided on the at least one strap to secure the at least one strap to the first securing means.
The first securing means is conveniently selected from the group comprising a through-going hole, a recess, a cavity, a plug, a screw, a screw nut, a box nut, a cap a means, a male coupling part, a female coupling part, or combinations of these. This list is however not exhaustive.
The knife handle may e.g. have a premade hole, or a hole is made for the purpose of subsequently securing the at least one strap of the safety means at the free end of said knife handle. The first securing means is provided at the free end of the knife handle, e.g. in elongation of the knife handle or a small distance from the outer free end of said knife handle, to secure the at least one strap to said knife handle. Optionally, a second securing means serves to secure the at least one strap in or to the first securing means, e.g a first securing means in the form of a through-going hole or recess.
In a very simple embodiment a strap loop may be passed through a through-going hole or otherwise secured to a corresponding first securing means so that two strap loop parts protrudes on each side of the hole. The strap loop parts can then be secured to the hole by simply tying a knot. In this way two opposite straps are created for the fingers. In an alternative embodiment the strap can be integrated in the knife handle, e.g. during moulding the knife handle, and extend from or at the free end of the knife handle, e.g. in extension of said knife handle. The above suggested ways of providing the safety means at the free end of the knife handle and/or in proximity of the free end of the knife handle should not be taken as an exhaustive list. Conventional means and combinations of these with the aforementioned means are intended within the scope of the present invention.
A suitable second securing means is selected from the group comprising a plug means fitable into the first securing means, the strap itself, a means for tying the strap to the first securing means, a female coupling part, a male coupling part or combinations of these. This list is however not exhaustive. A plug means, that can be force-fitted into a hole or recess, provides a reliable fixation of the safety means to the knife handle. The first securing means and the second securing means can be of the kind for permanent or detachable securing of the strap to the knife handle.
Within the scope of the present invention the first securing means and the second securing means are configured to be easy-to-clean in order to comply with sanitary regulations and similar guidelines. Thus the joint between the first securing means and the second securing means should preferably be of a kind not accumulating residues from the cutting process so that creation of a bacterial bed is prevented.
Any complementarily shaped securing means may be used to secure the safety means to the knife handle. Snap fittings, frictional engagement, gluing, screws and combinations of these are just examples of ways and means to accomplish securing. Some of these means are most preferred for detachable securing and some for non-detachable securing.
The at least one strap may have a non-stick surface or a protective coating, such as a grease rejecting coating or grease rejecting surface, in order to comply with e.g. sanitary regulations and Food and Drug Administration requirement, in particular requirement for use in slaughterhouses and butcheries.
The at least one strap may be either disposable or reusable. In case of a disposable strap, the strap can simply be cut loose after use, or the second securing means can be otherwise detached from the first securing means. A safety knife free of strap can be cleaned effectively. When the knife is to be used again a new strap is secured to the free end of the clean knife handle. In this embodiment a reduced number of parts needs cleaning thereby reducing the risk that parts of the knife are not been effectively cleaned. In re-usable designs of the safety knife according to the present invention no or substantially no cavities, in which residues such as fat and other slaughterhouse waste, such as blood and meet, can accumulate, are attempted avoided.
In the preferred embodiment the safety means has only one strap, but in an alternative embodiment two straps may be present. Even more straps can be provided and straps for all fingers are foreseen within the scope of the present invention.
The at least one strap is only attached at one single location on the knife handle, namely at or to the free end of the knife handle, thereby leaving the main part of the at least one strap free for being hooked by a finger/the fingers passing through the opening of the one or more straps.
If the least one strap is made of a flexible material the operator can easily move his/her hand around on the knife handle, thus the operator can reposition the hand without taking the finger out of the at least one strap's strap opening. By the term “flexible material” is understood a material that is resilient, bendable but not stretchable. Examples of suitable materials include but are not limited to a plastic strap, a rope, a wire with a plastic coat or combinations of these. It is important that the at least one strap has a fixed length and can be moved around a longitudinal axis of the knife handle. Preferred materials are chemical resistant and mechanical strong, not susceptible to break and rupture, not susceptible to elongation in response to heat, and have good wear resistance.
The invention further relates to a knife for use in the method, which knife has a knife handle, a knife blade extending in elongation of the knife handle, safety means including at least one strap having a strap opening, and the at least one strap is secured to or at a free end of the knife handle. The knife comprises at least one strap with a strap opening having a size selected to configure the at least one strap in a first position and a subsequent second position in which,
As stated during the description of the method above the at least one strap may be detachably or non-detachably secured to or at the free end of the knife handle, to allow the operator to shift or not shift between straps, and allow replacement or disposal of a used strap.
The knife handle or an elongation of the knife handle may be provided with a first securing means for securing the at least one strap to or at the free end of said knife handle, and optionally a second securing means may be provided on the at least one strap to secure it to the first securing means.
The knife and the method described above is particular efficient to use in slaughterhouses or butcheries because the operator is free of the heavy conventional safety glove, use of which often is prescribed for safety purposes.
The invention will be described in further details below with reference to the drawing and exemplary embodiments of a safety knife in methods according to the present invention.
In the assembled state of the safety knife shown in
So after having arranged the thumb 9 through the strap opening 7′ of the strap 7, as e.g. shown in
The bush 8 plugs the through-going hole 6, thereby serving as a retainer when the strap 7 is tensioned during use of the safety knife 1. Thus if the bush 8 is releasable, e.g. in a detachable embodiment, or accidentally gets loose of the engagement inside the through-going hole 6, this way of arranging the bush on the side of the knife handle opposite the palm side of the hand creates interaction of bush 8 and the through-going hole 6 so as to provide additional safety against loosing the strap during use of the safety knife.
As in the first embodiment of the safety knife 1 the thumb 9 is passed through the strap opening 7′ of the strap 7, as shown in
Use of the method according to the present invention eliminates the risk that the operator gets injured due to the hand 10 accidentally slipping forward in contact with the cutting edge 13. At least one finger is always caught by the at least one strap, but user-friendliness is not compromised. The operator can still work fast and effectively. The operator is safe from cut injuries at all time during use of the knife according to the present invention. A particular advantage is that the safety knife's knife handle can easily be angularly repositioned and rotated in the operator's hand if desired without loosing the safety attachment between strap and finger.
The knife and the method is particular useful in slaughterhouses where the working pace is high and pressure on the workers often causes cutting injuries.
| Number | Date | Country | Kind |
|---|---|---|---|
| 13150248.6 | Jan 2013 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2013/076678 | 12/16/2013 | WO | 00 |
