The present disclosure relates to the field of retractable knives, and specifically to a knife with a specialized or optimized balance weight and blade length.
Knives are available in a variety of designs. Generally, knives can be configured with either a fixed blade or a moveable blade. With a fixed blade knife, as the name suggests, the blade is attached to the handle such that the blade is in a fixed position and cannot be moved. Moveable blade knives allow the blade to move relative to the handle, typically between a stowed position for carrying, and an extended position for use. Moveable blade knives are available in a variety of configurations. A common configuration is the so-called “Swiss Army knife”, a folding knife where the blade pivots relative to the handle to fold into the handle for storage, and fold out to an extended position for use. Examples of other configurations include a butterfly knife, where the handle splits and pivots relative to the blade, and out-the-front (OTF) knives, where the blade is retained within the handle under spring tension. The spring tension propels the knife out of the handle in a linear fashion into an extended position when a catch or button is tripped. In some implementations (e.g. “double action” knives), the knife may also be held under spring tension when extended, so that the blade will retract back into the handle when the catch or button is subsequently tripped again
Embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings. Embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings.
In the following detailed description, reference is made to the accompanying figures which form a part hereof, and in which are shown by way of illustration embodiments that may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of embodiments is defined by the appended claims and their equivalents.
Various operations may be described as multiple discrete operations in turn, in a manner that may be helpful in understanding embodiments; however, the order of description should not be construed to imply that these operations are order dependent.
The description may use perspective-based descriptions such as up/down, back/front, and top/bottom. Such descriptions are merely used to facilitate the discussion and are not intended to restrict the application of disclosed embodiments.
The terms “coupled” and “connected,” along with their derivatives, may be used. It should be understood that these terms are not intended as synonyms for each other. Rather, in particular embodiments, “connected” may be used to indicate that two or more elements are in direct physical contact with each other. “Coupled” may mean that two or more elements are in direct physical contact. However, “coupled” may also mean that two or more elements are not in direct contact with each other, but yet still cooperate or interact with each other.
For the purposes of the description, a phrase in the form “A/B” or in the form “A and/or B” means (A), (B), or (A and B). For the purposes of the description, a phrase in the form “at least one of A, B, and C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C). For the purposes of the description, a phrase in the form “(A)B” means (B) or (AB) that is, A is an optional element.
The description may use the terms “embodiment” or “embodiments,” which may each refer to one or more of the same or different embodiments. Furthermore, the terms “comprising,” “including,” “having,” and the like, as used with respect to embodiments, are synonymous.
The feel of a knife is dependent upon a number of different factors, including its overall balance: whether the knife is blade heavy, handle heavy, or balanced between the two. This balance is typically considered with the knife in an extended or operational position. A proper balance on a knife can enhance ease of use when cutting, and also reduce operator fatigue when the knife is used for an extended period of time. Depending upon the intended application of a knife, the overall weight and heft may also impact comfort. If a knife is too light and/or handle-heavy, the user may need to expend a greater effort to cut compared with a knife that is balanced, where at least some of the blade's weight can be used to help cutting. Similarly, if a knife is too heavy or blade-heavy, the user may find the knife unwieldly and difficult to control precisely.
Blade length also impacts usability. As a general rule, longer knife blades result in heavier knifes, although can offer more leverage in some situations. Moreover, as a knife blade gets longer, typically the handle gets heavier, both due to increased length to accommodate the blade length, and because of greater internal reinforcement needed to maintain a handle rigidity sufficient to handle stresses imposed during use. The handle may also need to be thicker to accommodate the knife's action components, which correspondingly need to be larger to accept the longer blade. To maintain a good weight ratio, the blade itself may need to be made thicker than otherwise necessary to balance out the larger handle. As a result, larger knives can rapidly increase in weight, and become effectively unusable for people who lack sufficient arm and/or hand strength.
Embodiments disclosed herein provide a knife that has an optimized weight ratio and blade proportion. By adjusting the construction of the internal structures of the handle and the enclosed blade action, the handle can be kept relatively smaller and lighter, but without sacrificing rigidity and durability. Consequently, the blade can also be kept thinner, maintaining a good balance while still allowing the knife to be relatively light. Furthermore, the disclosed embodiments reduce the number of components required for the knife, which aids assembly and allows for more secure attachment of the various components.
In the depicted embodiment, handle 102 encloses the various components of the knife 100's action, and further stores blade 104 when the action is in a retracted configuration. Handle 102 is thus sized based upon the length and size of the blade 104 and the associated action components. Furthermore, handle 102 may be shaped ergonomically, to accommodate the hand of an average user as well as to provide comfort and control of the blade 104 when the knife 100 is in use. The exterior of handle 102 may include texturing, stippling, finger notches and/or other features to enhance grip and control when in use. The shell or housing of handle 102 may be constructed from a material that is sufficiently durable to withstand the forces imposed upon knife 100 while in use, such as plastic, composites, metal, wood, bone, or another suitable material. The choice of materials can impact the overall weight and balance of knife 100, and may be selected with respect to the material used for blade 102, as well as the components of the knife action. Various components of the action will be described below.
Blade 104 may be smooth, as shown in the depicted embodiment, serrated, or a combination of either. Blade 104, in embodiments, may have various other features, depending upon the intended use of knife 100. Blade 104 is configured to slide in and out of handle 102, to move between an extended position for use, and a stored position. In some embodiments, blade 104 slides substantially along the longitudinal axis defined by handle 102 and blade 104, and passes into or out of handle 102 via aperture 108. Depending upon the configuration of handle 102, in other embodiments blade 104 may travel into handle 102 at an angle relative to the longitudinal axis of handle 102. In still other embodiments, blade 104 may define a plane and handle 102 may define a second plane, and the plane of blade 104 may diverge from the plane of handle 102 as blade 104 travels, to allow for improved handle 102 ergonomics.
Blade 104 may taper from a thicker ridge 114 to a sharpened edge 116, for cutting. Ridge 114 forms the spine of blade 104, providing structural rigidity to blade 104 and resisting bending. The thickness of ridge 114 may depend upon the materials used to construct blade 104, as well as the overall length of blade 104. A longer blade 104 may necessitate a thicker ridge 114 and, correspondingly, a thicker handle 102. Blade 104 may be constructed from any suitable material that can be sharpened to hold edge 116, such as carbon steel, damascus steel, carbide, ceramic, composites, or another suitable material now known or later developed. The arrangement of the ridge 114, including its thickness and taper, if any, may also impact the overall balance of knife 100. For example, if ridge 114 is thicker proximate to handle 102 (when blade 104 is in an extended position) and thinner at its tip, distal from handle 102, then the weight of blade 104 will be more centered around or shifted toward aperture 108. Conversely, if ridge 114 is thicker nearer the tip, distal from handle 102, then the weight of blade 104 may be centered further along its length, away from handle 102. Thus, by altering the shape of blade 104, such as by changing the profile of ridge 114, the overall balance of knife 100 can be adjusted. Further, it will be understood that the balance of blade 104 may impact the construction and weighting of handle 102 in order to achieve a particular desired balance of knife 100. Conversely, the configuration of blade 104 and its ridge 114 can be adjusted in connection with a given configuration of handle 102 to achieve a desired weight and/or balance of knife 100 when in an extended configuration. These considerations further may be balanced against a desired ratio of blade length to handle length, where a desired ratio may constrain blade 104 and its ridge 114 to a particular balance and configuration.
Knife 100, in the depicted embodiment, includes a button 106 for actuating the action of knife 100, causing blade 104 to be propelled from handle 102. Where knife 100 is a double action knife, button 106 may be subsequently toggled to cause the action of knife 100 to retract blade 104 back into handle 102. In some other embodiments, button 106 may be used to unlock blade 104 so that it can be manually slid back into handle 102. In the depicted embodiment, button 106 is a slide that can move parallel to the longitudinal axis of handle 102. In other embodiments, button 106 may move a different direction, such as transverse to the longitudinal axis, or may be an actual button that can be depressed to actuate the action of knife 100. The configuration of button 106 may depend upon the nature of the action of knife 100.
In various embodiments, the length of handle 102 is selected with respect to the length of blade 104. In most embodiments, the blade size is maximized relative to the handle size, to the point where increasing the blade size further would result in a loss of space needed for the action components; at such a point, the handle must be increased to achieve further blade size increases. Thus, handle 102 is designed be sufficiently long to fully enclose blade 104 and the action components. Possible additional length may be added to ensure a comfortable grip in some embodiments where the length of blade 104 is relatively short compared to width of an average user's grip. However, generally, embodiments seek to maximize the blade that can be installed into a given handle, which can be achieved by altering the configuration of the handle and action components, examples of which are described herein.
With respect to the ratio of blade length 110 to handle length 112, in one possible embodiment, a ratio of a 3.5″×0.85″ blade (length×height) to a 2.8 oz. overall weight, where handle 102 is manufactured from plastic, has been determined to provide optimal handling. Blade length 110, in the depicted embodiment, is approximately 3.5″, with a more precise length of 3.5132″, and handle length 112 is approximately 4.7″, with a precise length of 4.7142″. This yields an overall length of knife 100 of approximately 8.2″, and more precisely 8.2218″. Note that the total length is slightly less than adding blade length 110 to handle length 112, which yields a sum of 8.2274″; this is due to a small portion of the blade length 110 overlapping the end of handle length 112. Such an embodiment may have a weight of approximately 2.8 oz. In other embodiments, the blade may have a thickness of between approximately 0.100 to 0.140 inches. In still another embodiment, depicted in
In the first example embodiment discussed above, there is a length to weight ratio of 8.2″ to 2.8 oz., or approximately 2.93:1. In the second example embodiment, depicted in
Turning to
Springs 204 may each be disposed within a corresponding groove formed by the ribs of ribbed first liner 202. The use of a groove can help position each spring 204 in closer proximity to blade 104, which can save space within handle 102. While the depicted embodiment includes two springs, fewer or more springs may be utilized depending upon the requirements of a given implementation. The springs 204 may be calibrated to supply sufficient force to propel blade 104 through aperture 108 to a fully extended position, with consideration to the overall configuration of the action 200. In some embodiments, the springs 204 may cease providing force before blade 104 is fully extended, relying upon the momentum imparted to blade 104 by springs 204 and/or gravity to carry it to a fully extended position. In embodiments where action 200 is of a double-action configuration, the momentum/gravity may be sufficient to impart a tension on the springs 204 prior to the end of the travel of blade 104 so that springs 204 are sufficiently biased to retract blade 104 into handle 102. Springs 204 may be manufactured of any suitable spring material.
In the depicted embodiment, blade 104 may be held in either a stowed position within handle 102 or a fully extended position outside of aperture 108 by the action of either first latch 214, when the blade 104 is extended, or second latch 216, when the blade 104 is stowed. Each of first latch 214 and second latch 216 interacts with a tab or lip (not shown) on the tang of blade 104 to retain blade 104 in the extended or stowed position, respectively. First latch 214 and second latch 216 are each spring biased to engage with the tab or lip once the tab or lip clears the latch 214 or 216. First liner 202 and one or more catches 208 cooperate with an aperture or apertures 210 disposed on or through the tang of blade 104, to impart force from springs 204 to blade 104 for either extension or retraction. When blade 104 is stowed, catch 208 in the depicted embodiment is engaged with aperture 210. When blade 104 is extended, a second catch (not shown) disposed proximate to aperture 108 is engaged with aperture 210. Although a single aperture 210 is depicted, in some embodiments, the tang of blade 104 may have two apertures 210 arranged along the longitudinal axis; a forward aperture 210 to engage with a forward catch, and a rear aperture 210 behind the forward aperture to engage with the rear catch 208.
In embodiments, button 106 impinges upon or is otherwise coupled to a trigger protrusion 212 formed from first liner 202 so that sliding button 106 either forward (towards aperture 108) or rearward longitudinally along handle 102 likewise causes first liner 202 to slide longitudinally within handle 102. Where action 200 is double-action (both extends and retracts blade 104), as in the depicted embodiment, in the case of blade 104 extension, button 106 is slid forward (towards aperture 108), causing first liner 202 to likewise slide towards aperture 108. As first liner 202 slides forward, it engages the catch closest to aperture 108 while catch 208 at the rear of handle 102 is engaged with aperture 210. As a result, tension is applied to springs 204. At the same time, ramp 218 on first liner 202 contacts latch 216, which causes latch 216 to be forced down away from the tang of blade 104, and to clear the lip on the tang of blade 104. Once latch 216, which was preventing forward movement of blade 104 by engaging the lip of blade 104's tang, clears the lip, springs 204 drive blade 104 forward towards aperture 108 and out of handle 102, the force imparted by the interaction of catch 208 with aperture 210. As blade 104 slides forward, aperture 210 engages with the forward catch proximate to aperture 108, causing springs 204 to be at least partially pre-loaded. A lip on the tang of blade 104 slides past upper latch 214, which drops behind the lip. The springs 204 arrest the forward movement of blade 104 and bias it against upper latch 214, locking blade 104 in an extended position.
For retraction, the process is essentially the same, except in reverse: Button 106 is slid rearward (away from aperture 108), causing first liner 202 to slide rearward. As it slides rearward, it contacts catch 208 at the rear of handle 102, which further tensions springs 204. At the same time, ramp 220 on first liner 202 contacts upper latch 214, forcing it up and causing it to clear the lip on the tang of blade 104. Once cleared, springs 204 drive blade 104 rearward into handle 102. Aperture 210 picks up catch 208 and causes springs 204 to be at least partially pre-loaded. The lip on the tang of blade 104 clears past lower latch 216. Springs 204 arrest rearward movement of blade 104 and bias it against lower latch 216, locking blade 104 in the stowed position within handle 102.
In embodiments, button 106 may be coupled to the trigger protrusion 212 such that button 106 does not slide in the same plane as blade 104. In some such embodiments, the plane of travel of button 106 is not parallel to the plane of travel of blade 104. The arrangement of the planes of travel may be adjusted to accommodate the components of action 200 in the most compact fashion possible.
As discussed above, action 200 has two catches 208 in the disclosed embodiment, although the forward catch nearest aperture 108 is not depicted in
In
To help maintain second liner 206 in its correct position, the half of handle 102 may include a plurality of posts 306 (
The use of posts 306 with crush ribs 308 allows handle 102 to determine the correct position of second liner 206, as well as to maintain the correct width of central slot 304, even if second liner 206 is not manufactured with a precisely dimensioned central slot 304. Furthermore, the crush ribs 308 can help to add structural integrity to the liner, as well as helping to resist deformation of either handle 102 or second liner 206, thereby helping to retain the desired fit between the liner and the blade or blade carrier block for smooth operation, as discussed above. Without such structures, placing the oval apertures 302 through second liner 206 could detrimentally affect the structural integrity of second liner 206, and allow the width of central slot 304 to vary beyond acceptable limits. Thus, second liner 206 would need to be heavier and/or manufactured to tighter tolerances, which may increase manufacturing costs. The use of posts 306 and crush ribs 308 allows second liner 206 to be lightened, and also eases manufacturing, as the tolerances for handle 102 can be better controlled over the tolerances for the width of central slot 304 of second liner 206. Crush ribs 308 and/or posts 306 may be manufactured as part of handle 102, as a separate rivet, e.g. a crush rivet that includes both post 306 and crush ribs 308, or a combination of the two, e.g. the crush ribs may be molded as part of handle 102 while post 306 is formed by inserting a rivet into handle 102 between the molded crush ribs. Other implementations may be possible as well.
Referring to
In the depicted embodiment of
Although certain embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent embodiments or implementations calculated to achieve the same purposes may be substituted for the embodiments shown and described without departing from the scope. Those with skill in the art will readily appreciate that embodiments may be implemented in a very wide variety of ways.
This application is intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it is manifestly intended that embodiments be limited only by the claims and the equivalents thereof.
The present application claims priority to U.S. Provisional Patent Application No. 63/069,613, filed Aug. 24, 2020, entitled KNIFE WITH SPECIALIZED BALANCE AND BLADE LENGTH, the entire disclosure of which is hereby incorporated by reference.
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