The present disclosure relates to hand operated cutting tools. More particularly, the present disclosure relates to hand operated cutting tools.
Hand operated cutting tools are used in a variety of applications (e.g., pruning or trimming branches and the like). Some hand operated cutting tools may include devices intended to increase the available leverage (e.g., levers and/or gears) to increase a force provided by the tool to the cut an object. However, such mechanisms are typically large, which increase weight and complexity to the tool. Such large mechanisms are especially undesirable in smaller hand operated cutting tools, such as pruners, where users desire light-weight and ease of maneuverability.
One embodiment relates to a hand operated cutting tool. The hand operated cutting tool includes a first cutting member; a first handle coupled to the first cutting member; a second handle having a second cutting member; and a pivot connection pivotably coupling the first handle to the second handle. According to one embodiment, the first cutting member includes a cutting device that defines a bow-shaped cutting profile, wherein the bow-shaped cutting profile facilitates an acceleration of a cut-point position defined by an interaction of the first and second cutting members as the first and second handles move from a fully open position to a fully closed position.
Another embodiment relates to a scissors. The scissors includes a first cutting member having a first cutting device, wherein the first cutting device defines a bow-shaped cutting profile; a first handle coupled to the first cutting member; a second cutting member having a second cutting device; a second handle coupled to the second cutting member; and a pivot connection pivotably coupling the first handle to the second handle, wherein the first and second handles are movable between a fully open position and a fully closed position. According to one embodiment, a substantial linear cut force profile exists as the first and second handles move from the fully open position to the fully closed position.
Still another embodiment relates to a one-hand operated cutting tool. The one-hand operated cutting tool includes a first cutting member having a first cutting device, wherein the first cutting device defines a bow-shaped cutting profile; a first handle coupled to the first cutting member; a second cutting member having a second cutting device, wherein the second cutting devices a bow-shaped cutting profile; a second handle coupled to the second cutting member; and a pivot connection rotatably coupling the first handle to the second handle, wherein the first and second handles are movable between a fully open position and a fully closed position, wherein in the fully open position the first and second handles are at a maximum separation distance and in the fully closed position the first and second handles are a minimum separation distance. According to one embodiment, movement of the handles from the fully open position to the fully closed position results in a substantially linear cut force relationship for the one-hand operated cutting tool.
Referring to the Figures generally, various embodiments disclosed herein relate to a hand operated cutting tool (e.g., a scissors) with a relatively flatter cut force profile compared to conventional hand operated cutting tools. In this regard and as used herein, the term cut force profile (also referred to as the cutting force profile) refers to the cut force required to cut through an object as the jaws or cutting members of the tool are actuated from fully open to fully close (i.e., from a point of maximum separation to minimum separation). For example, in a conventional hand operated scissors, a force required to cut through an object increases as the cut position moves towards a tip of the scissors (i.e., as the handles of the scissors travel from the fully open position to a fully closed position). Such an increase in force may reduce ease of use and frustrate users. This problem may be compounded due to the typically small size of scissors, which makes implementation of a mechanical advantage mechanism difficult.
According to the present disclosure, a hand operated cutting tool, such as a scissors, may be provided with first and second cutting members that are coupled to first and second handles, respectively. At least one of the first and second cutting members may include a cutting device (e.g., a blade, serrated blade, etc.) having a crescent or bow-shaped cutting profile. Applicants have determined that such a profile may accelerate a cut-point position (i.e., a region where the cut is occurring) as the handles move from the fully open position to the fully closed position and to decelerate proximate the fully closed position of the tool. As a result, the cut force profile remains relatively flat and substantially without a parabolic increase like conventional tools. Advantageously, a mechanical advantage is provided relative to conventional systems, and users of the tool may experience a relatively easier ability to cut objects, which may increase an endurance of the user with the tool. Moreover, the relatively flatter cut force profile may be achieved without implementing complex mechanical advantage mechanisms, which in turn may make fabrication and assembly of the hand operated cutting tools of the present disclosure more efficient and cost effective. Further, the relatively flatter cut force profile may provide an increased amount of control over the tool to, in turn, provide enhanced accuracy and precision to users. These and other features and advantages are described more fully herein.
It should be understood that while the present disclosure is primarily described herein in regard to scissors and shears as hand operated cutting tools, the present disclosure contemplates implementation with other hand operated cutting tools. For example, the present disclosure may also be implemented with a pruner, a snip, and so on. Moreover, while the present disclosure is also described mainly in regard to one-hand operated cutting tools, the present disclosure may also be implemented with two-hand operated cutting tools (e.g., hedge shears). All such variations are intended to fall within the scope of the present disclosure. Moreover, as referred to herein, the object of a cutting tool may preferably refer to sheet goods (e.g., a sheet of paper, a sheet of cardboard, etc.), where there may be a consistent cut-force required along a length of the tool. However, such an application is not meant to be limiting as the object of the cutting tool may also include a wide variety of objects, such as branches, twigs, weeds, small trees, etc.
Referring now to
As described below, moving the handles 12, 14 closer to and further from each other actuates an opening and a closing of the cutting members 30, 40, where movement from the fully open to the fully closed position corresponds with a cutting a stroke of the scissors 10. In this regard, the cutting stroke is characterized by the cutting of the scissors 10 occurring or being able to occur. In one embodiment, each of the coupled first handle 12 and first cutting member 30 and the second handle 14 and second cutting member 40 are of unitary or integral construction. For example, each of the coupled first handle 12 and first cutting member 30 and second handle 14 and second cutting member 40 may be formed from a cast metal (e.g., aluminum) where an over-molded portion (e.g., rubber) is applied to each handle portion 12, 14 to define an ergonomic user interface portion. According to another embodiment, each of the coupled first handle 12 and first cutting member 30 and the second handle 14 and second cutting member 40 are constructed from two or more components. For example, each handle 12, 14 may be a first component that is coupled to each of the first and second cutting members 30, 40, respectively, via, for example, one or more fasteners (e.g., a bolt) or another joining process (e.g., an interference relationship, welding, etc.). In yet another example, one of the coupled handles and cutting members may be of unitary construction while the other coupled handle and cutting member is constructed from two or more components. All such variations are intended to fall within the scope of the present disclosure.
As shown, the first handle 12 and first cutting member 30 are pivotably coupled to the second handle 14 and second cutting member 40 at a pivot connection 20. The pivot connection 20 may include any type of pivot connection including, but not limited to, a bolt, a pin, a lug, a rivet, a stud, and so on. In use, the handles 12, 14 and cutting members 30, 40 rotate about the pivot connection 20 during operation of the scissors 10. Further, while the pivot connection 20 is illustrated as stationary or fixed, this depiction is for illustrative purposes only. In other embodiments, the pivot connection 20 may be structured as a compound action type pivot connection. The compound action type connection may include a sliding joint. For example, an elongated aperture defined in each of the cutting members may receive a pivot member (e.g., bolt, pin, etc.), where the pivot member may slide or move within the elongated aperture. The sliding joint may be used to change the relative positioning of one cutting member to the other cutting member. The compound action type connection may also include a sliding joint with ridges or catches within the elongated apertures, where the ridges or catches facilitate the catching of the pivot member to lock or substantially lock a desired relative positioning of each cutting member. Accordingly, the term pivot connection is meant to be broadly interpreted to correspond with a variety of different types of pivot connections.
The first cutting member 30 is shown to include a first cutting device 31, while the second cutting member 40 includes a second cutting device 41. As shown, the first and second cutting devices 31, 41 are structured as cooperating blades that engage with each other in a shearing relationship to cut through an object. In other embodiments, at least one of the first and second cutting devices 31, 41 may be structured as any other cutting device including, but not limited to, a serrated or toothed edge, an anvil (e.g., a relatively flat or blunt edge that may cooperate with a blade or other cutting device to effect cutting through an object), etc.
As shown, the first cutting member 30 includes a first end 32 proximate the pivot connection 20 and a second end 33 (e.g., the tip of the cutting member 30) furthest from the pivot connection 20. Between the ends 32, 33, the cutting device 31 may define a convex or bow-shape profile 34 (e.g., crescent shaped, arched, etc.), where the convex nature is based on the orientation of the cutting device 31 relative to the object being cut. It is important to note that while the cutting device 31 (and/or cutting device 41) may define a bow-shaped profile, the characteristics of the cut or shear produced by the cutting tool (e.g., scissors 10) on the object remain unchanged or substantially unchanged. For example, the cut line on the object (e.g., a sheet of paper) is still dictated by the user by, e.g., rotating and/or turning the tool. Accordingly, the bow-shaped profile 34 refers to the shape/configuration of the cutting device and not the object cut characteristics, such that the bow-shaped profile 34 may advantageously still produce the same or substantially the same object cut characteristics.
The profile 34 may have a variety of radii of curvature, R. According to one embodiment, the radius of curvature, R, is convex-shaped relative to the object of the scissors 10 (i.e., the sides surrounding the peak or crest of the profile slope away from the object when the object is inserted between the two cutting devices). In this regard and as shown, the bow-shaped profile 34 may be characterized by a peak or crest in or around the middle of the cutting device 31 (e.g., substantially in between the first end 32 and the second end 33) with the sides of the cutting device 31 sloping away from the peak or crest toward each of the first and second ends 32, 33 respectively. According to one embodiment, the profile 34 corresponds with a polynomial function. In one instance, polynomial function may correspond with a quadratic curve corresponding with the convex-shaped profile, which is shown in the example depicted.
In the example depicted, an asymmetric cutting device configuration is depicted. In this regard, only one cutting device of the two cutting devices is shown to include a bow-shaped cutting profile (hence, asymmetric). In other embodiments (see
A fully open handle position for the scissors 10 is shown in
Based on the above, the angle 50 may be referred to herein as the handle angle, which is indicative of the angle of separation between the handles 12, 14. According to one embodiment, the handle angle 50 may be defined as the intersection angle between a first line defined by an end point at the pivot point 20 and a fixed point on the handle 12 and a second line defined by an end point at the pivot point 20 and a fixed point on the handle 14. In this regard, each of the first and second lines share a common point to define an intersection location at the pivot point 20. In this embodiment, the fixed points on each of the handles 12 and 14 for each of the first and second lines may be positioned in any desired position. For example, the fixed points may be positioned at an approximate mid-point of the width of the handles 12 and 14 where the “width” refers to the area of the handles 12, 14 shown in
The bulk blade opening angle 52 may be defined by any suitable definition accepted by those of ordinary skill in the art. For example, according to one embodiment, the bulk blade opening angle 52 may be defined as the angle between a first line defined by an end point at the pivot point 20 and a fixed point on the first cutting member 30 and a second line defined by an end point at the pivot point 20 and a fixed point on the second cutting member 40. According to another embodiment, the bulk blade opening angle 52 may be defined in any other manner. All such variations are intended to fall within the scope of the present disclosure. Finally, the angle 57 may be referred to herein as the “cutting device angle” or “cutting edge angle” and refers to the angle of separation between an edge of the first cutting device 31 and an edge of the second cutting device 42 at the cut-point 54 (i.e., the angle between the cutting devices 31 and 41 where the actual cut is occurring or about to occur). The cut-point 54 refers to the intersection of the cutting devices 31 and 41 that cause the shear and cutting of the object (i.e., where the cutting devices 31, 41 engage or are about to engage with the object to cause the cutting or shearing of the object). In this regard and as shown, the angle 57 may be different from the angle 52.
In operation, as the handles 12, 14 travel from a fully open position to a fully closed position, the angles 50 and 52 decrease and the cut-point 54 moves towards the second end 33. Similarly, a distance 56 between the pivot connection 20 and the cut-point 54 increases during movement of the handles 12, 14 towards the fully closed position.
Applicants have determined that based in part on the bow-shaped profile of the cutting device, such as cutting device 31, a speed of the cut-point 54 may be increased to facilitate a faster cut with relatively less force. This and other characteristics of the present disclosure may be described and shown with reference to
Referring now to
Referring now to
It should be understood that while the cutting edge angle versus the bulk blade opening angle (curve 401) is shown to be linear or substantially linear, the present disclosure contemplates that a non-linear relationship may be created or formed between the cutting edge angle and the bulk blade opening angle. In this regard, the linear or substantially linear relationship is not meant to be limiting. In particularity, Applicants have determined that to create a perfectly flat cut force profile, the relationship would be non-linear in nature (e.g., correspond with an exponential or polynomial increasing function where the cutting edge angle increases based on that function as the bulk blade angle decreases).
Referring now to
Accordingly, referring to
Referring to
In equation (1), “D” refers to the distance between the pivot connection 20 and the cut-point 54 (i.e., reference number 56 in
Referring now to
In equation (2), the “cut force” term may be measured (e.g., via one or more strain or force gauges) or otherwise determined (e.g., estimated) and may refer to/be indicative of the force to operate the cutting tool to cut through/shear an object. Of course, the cut force for different objects may vary (e.g., cardboard versus paper); in this simulation, the object is unchanged to eliminate or substantially reduce any variability with respect to the simulated cut force. The term “hand strength” may represent a user's hand strength (e.g., a squeeze strength as represented by the tightness of a fist a user can make) as a function of position (e.g., from the full open position to the full close position). This may be a measured, predicted, or estimated term. As shown, first, the curve 801 is relatively flat compared to the curve 802. Second, the curve 801 does not include a spike in difficulty like that shown in the curve 802 around twenty-five (25) percent cut length. Thus, relatively less difficulty may be experienced by the user of the cutting tool of the present disclosure.
As shown in
However, in this embodiment and relative to the scissors 10, the scissors 900 is shown to include symmetric cutting members 930, 940. In this regard, symmetric indicates that each cutting member includes a bow-shaped cutting device. As shown, the first cutting member 930 includes a first cutting device 931 (a cutting device of the second cutting member 940 is hidden by the first cutting member 930 in
As mentioned above,
While
Like the scissors of
According to one embodiment, the cutting members 1030, 1040 may be constructed from a metal-based material (e.g., stainless steel). In other embodiments, the cutting members 1030, 1040 may be constructed from any material that may be used with or contemplated for use with a shears. All such variations are intended to fall within the scope of the present disclosure.
It is important to note that the construction and arrangement of the elements of the hand operated cutting tool, shown as a scissors and a shears, is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible without materially departing from the novel teachings and advantages of the subject matter recited.
Accordingly, all such modifications are intended to be included within the scope of the present disclosure. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the preferred and other exemplary embodiments without departing from the spirit of the present disclosure.
As utilized herein, the terms “approximately,” “about,” “substantially,” and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and are considered to be within the scope of the disclosure.
For the purpose of this disclosure, the term “coupled” means the joining of two members directly or indirectly to one another. Such joining may be stationary or movable in nature. Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another. Such joining may be permanent in nature or may be removable or releasable in nature.
In the claims, any means-plus-function clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating configuration and arrangement of the preferred and other exemplary embodiments without departing from the spirit of the present disclosure as expressed in the appended claims.
Filing Document | Filing Date | Country | Kind |
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PCT/US15/64764 | 12/9/2015 | WO | 00 |