The invention pertains to a cutting tool with a tool body having two cutting jaws that can be displaced relative to one another, wherein a first cutting jaw has a first mounting plane, on which a first blade part with a first blade edge is supported, wherein a second cutting jaw has a second mounting plane, on which a second blade part with a second blade edge is supported, wherein a cutting plane, along which the blade parts can be moved, essentially lies parallel to the first and the second mounting plane, wherein the blade edge of the respective blade part or the respective blade part as a whole is pivotable transverse to the associated mounting plane, wherein the blade part has an application surface for a driving force, which essentially extends orthogonal to the cutting plane, wherein mounting contact regions are formed in the mounting planes and a counterholding force acts upon a counterholding surface of the blade part or the blade edge, which is supported on the mounting plane, in said mounting contact regions on a side of the blade part or the blade edge facing away from the cutting plane, wherein a resultant force corresponding to the driving force furthermore forms a first line of force and a resultant force corresponding to the counterholding force forms a second line of force, wherein the first line of force and the second line of force intersect in an intersecting point in a cross-sectional plane, in which the cutting plane is illustrated in the form of a line, wherein the application surfaces are formed with a first distance orthogonal to the cutting plane and the counterholding surfaces are formed with a second distance from the respective application surface in the direction of the cutting plane, wherein a cutting force acting upon the blade parts during a cutting process furthermore causes a counterforce of a workpiece to be cut, wherein a line of action of the cutting force extends differently from a line of action of the counterforce, wherein each application surface has an end facing the cutting plane and an end facing away from the cutting plane, and wherein the ends of each application surface are located on the same side of the cutting plane.
Cutting tools of this type are sufficiently known from the prior art. They may be realized in the form of hand-operated cutting tools or in the form of cutting tools that are installed, in particular, in industrial cutting systems. The cutting force required for cutting a workpiece can be generated with the aid of an electric motor, a hydraulic pump or a compressor. The cutting tools have two blade edges that can be displaced relative to one another, wherein at least one or also both blade edges can be displaced relative to the tool body of the cutting tool. In this case, the aim is to keep a cutting gap being formed between the blade edges as small as possible such that partial regions of the workpiece cannot become jammed in the cutting gap, namely also when a load is exerted by the workpiece. This is particularly problematic, for example, when cutting finely stranded cables, individual strands of which may end up in the cutting gap. In addition, the direction of the cutting force, i.e. the line of action of the cutting force, is inclined relative to the cutting plane, i.e. the cutting direction, in dependence on the cutting geometry of the blade parts such that the blade parts are in turn pressed apart from one another transverse to the cutting plane when the tool is acted upon with a cutting force and the cutting gap is increased, particularly when cutting finely stranded cables in practical applications.
In order to respectively prevent the cutting gap from forming or increasing and to thereby also prevent parts of the workpiece from jamming in the cutting gap, it is known from the prior art to design cutting tools with permanently installed blade parts, in which the cutting gap practically can be adjusted to zero. This is frequently impossible in cutting tools with exchangeable blade parts or cutting jaws, e.g. also in universal tools of the type disclosed in U.S. Pat. No. 6,230,542 B1), DE 199 26 481 A1, which can accommodate different attachments for cutting, crimping and the like.
In order to eliminate a cutting gap being formed between the blade parts, the prior art according to publication US 2020/0055130 A1 furthermore discloses a cutting tool, in which the blade parts are mounted on the cutting jaws in the cutting plane such that the mounting planes of the cutting jaws, as well as the cutting planes of the blade parts, lie on top of one another. As a result of this design, the blade parts are pressed against one another during a cut and the cutting gap is reduced to zero due to a self-adjustment of the cutting tool.
Based on the above-described prior art, the invention aims to design an alternative cutting tool that is also suitable, for example, for cutting very finely stranded cables.
In order to attain this objective, it is proposed that the end facing the cutting plane defines the first distance and that the first distance and/or the second distance are chosen in such a way that the intersecting point lies in front of the line of action of the cutting force (FSchn) referred to a clockwise direction.
According to the invention, the blade edge or the blade part is now supported on the cutting jaw in a minimally movable manner relative to the cutting jaw (or alternatively the blade edge relative to an immovable partial region of the blade part) such that the reaction force retroacting upon the blade part from a workpiece does not lie on the line of action of the cutting force. Consequently, an angular deviation is achieved between the direction of the cutting force and the direction of the counterforce retroacting upon the blade part from the workpiece such that a torque is generated, wherein said torque tilts the two blade parts toward one another and thereby closes a potentially formed cutting gap. In order to effectively cut a workpiece, the line of action of the cutting force is not oriented parallel to the cutting plane, but rather tilted relative thereto. The angle between the cutting plane and the line of action of the cutting force usually is greater than 1° and smaller than 30° and preferably lies in a range between 10° and 25°. In this context, the counterforce refers to the force that retroacts upon the blade part from the workpiece when this blade part exerts a cutting force upon the workpiece.
It is proposed that the blade edge is pivotable to such an extent that a cutting gap formed between the blade parts while cutting the workpiece is at least reduced. The pivoting movement of the blade edge corresponds to a slight tilting movement relative to the mounting plane of the associated cutting jaw, wherein the extent of said pivoting movement lies on the order of 1° or fractions thereof. The blade edge particularly can tilt by one or more tenths of a degree. However, the cutting tool particularly may be designed in such a way that the cutting gap is closed by the pivoted blade edge in that the first blade edge of the first blade part contacts the second blade edge of the second blade part. However, at least a partial region of the cutting gap extending in parallel between the cutting planes is closed. This prevents very small partial regions of the workpiece to be cut, e.g. individual strands of a cable, from becoming jammed in the cutting gap.
The above-defined objective furthermore is attained by means of a cutting tool with a tool body having two cutting jaws that can be displaced relative to one another, wherein a first cutting jaw has a first mounting plane, on which a first blade part with a first blade edge is supported, wherein a second cutting jaw has a second mounting plane, on which a second blade part with a second blade edge is supported, wherein a cutting plane, along which the blade parts can be moved, essentially lies parallel to the first and the second mounting plane, wherein the blade edge of the respective blade part or the respective blade part as a whole is pivotable transverse to the associated mounting plane, wherein the blade part has an application surface for a driving force, which essentially extends orthogonal to the cutting plane, wherein mounting contact regions are formed in the mounting planes and a counterholding force acts upon a counterholding surface of the blade part or the blade edge, which is supported on the mounting plane, in said mounting contact regions on a side of the blade part or the blade edge facing away from the cutting plane, wherein a resultant force corresponding to the driving force furthermore forms a first line of force and a resultant force corresponding to the counterholding force forms a second line of force, wherein the first line of force and the second line of force intersect in an intersecting point in a cross-sectional plane, in which the cutting plane is illustrated in the form of a line, wherein the application surfaces are formed with a first distance orthogonal to the cutting plane and the counterholding surfaces are formed with a second distance from the respective application surface in the direction of the cutting plane, wherein a cutting force acting upon the blade parts during a cutting process furthermore causes a counterforce of a workpiece to be cut, wherein a line of action of the cutting force extends differently from a line of action of the counterforce, wherein each application surface has an end facing the cutting plane and an end facing away from the cutting plane, wherein the ends of each application surface are located on the same side of the cutting plane, wherein the end facing the cutting plane defines the first distance, wherein the first distance corresponds to one-tenth or more of an orthogonal distance between the mounting planes or the second distance corresponds to one-tenth or more of an orthogonal distance between the mounting planes or the first distance, as well as the second distance, corresponds to one-tenth or more of an orthogonal distance between the mounting planes, and wherein the intersecting point lies in front of a line of action of a cutting force, which acts upon the blade parts during a cutting process for cutting a workpiece, referred to a clockwise direction.
According to the invention, the cutting tool is designed in such a way that an intersecting point between a direction of a driving force, which acts upon an application surface of the blade part and serves for actuating the cutting tool, and a direction of a counterholding force of the cutting jaw, which acts upon a counterholding surface of the blade part essentially orthogonal to the mounting plane, lies in front of the line of action of the cutting force of the cutting tool—referred to the clockwise direction. As a result of this design, a torque acting upon the blade part is generated and said torque moves the pivotably supported blade part toward the cutting plane. The cutting gap is thereby reduced or completely closed in the above-described manner. The intersecting point between the direction of the driving force and the direction of the counterholding force defines the point, about which the blade part is able to tilt. Since the intersecting point now is, according to the invention, located in front of the line of action of the cutting force referred to the clockwise direction, the blade part tilts inward, i.e. toward the other blade part.
According to a first design variation of the cutting tool, it would furthermore be possible to pivotably support the blade part on the associated cutting jaw. Alternatively, a first partial region of the blade part with a blade edge may be pivotably supported on a second partial region of the blade part, which is immovably connected to the cutting jaw. According to yet another design variation, the cutting jaw carrying the blade part may be pivotably supported on the tool body of the cutting tool. The blade edge can be pivoted relative to the tool body of the cutting tool in all design variations such that the inventive effect for closing the cutting gap can be achieved. The concrete design of the cutting tool, particularly the location at which the pivotability for the blade edge is implemented, depends on the type of the respective cutting tool. In cutting tools with exchangeable blade parts such as universal tools, it is advantageous to support the blade parts on the cutting jaws in a minimally pivotable manner. In cutting tools with blade parts that are immovably fastened on the cutting jaws, it may in contrast be advantageous to pivotably support a partial region of the blade part carrying the blade edge on a stationary partial region of the blade part. The cutting jaw itself may ultimately also be designed so as to be pivotable on the tool body of the cutting tool.
According to a first embodiment, the blade part may be designed in such a way that the counterholding surface of the blade part, which is acted upon with the counterholding force, and the application surface of the blade part, which is acted upon with the driving force, are outwardly spaced apart from the cutting plane by such a distance that their intersecting point lies outside the line of action of the cutting force of the blade part acting upon the workpiece to be cut. This design can be achieved in that the counterholding surface, by means of which the blade part is supported on the mounting plane of the cutting jaw, is spaced apart from the cutting plane farther than in an embodiment according to the prior art, in which the intersecting point between the counterholding force and the driving force lies on the line of action of the cutting force. A contact surface between the counterholding surface of the blade part and the associated cutting jaw may be formed, for example, on a projection of the blade part that protrudes from an outer side of the blade part facing away from the cutting plane. In contrast to the remaining partial regions of the blade part, this projection protrudes into the mounting plane of the cutting jaw. The driving force of the cutting tool causing the displacement of the blade part also acts against an application surface of this projection such that the intersecting point between counterholding force and driving force is shifted outward, i.e. away from the cutting plane, relative to the line of action of the cutting force of the blade part. This results in a pivoting movement of the blade part in the direction of the cutting plane, namely such that the blade edge of the blade part runs ahead. The cutting gap is thereby respectively minimized or closed.
According to an alternative embodiment, the counterholding surface of the first blade part, which is acted upon with the counterholding force, may with respect to a direction extending parallel to the mounting plane be offset relative to the application surface of the first blade part, which is acted upon with the driving force, in the direction of the second blade part by such a distance that the intersecting point between the counterholding force and the driving force lies outside the line of action of the cutting force of the blade part acting upon the workpiece to be cut. In this embodiment, the application surface acted upon with the driving force and the counterholding surface acted upon with the counterholding force are spaced apart farther than in the above-described embodiment, wherein the application surface and the counterholding surface are offset relative to one another—referred to a direction extending parallel to the mounting plane. For example, the offset between the counterholding surface and the application surface may correspond to one-third to two-thirds of the height of the blade part referred to the direction extending parallel to the mounting plane. The offset preferably amounts to one-tenth or more of an orthogonal distance between the mounting planes. The counterholding force of the cutting jaw, which essentially acts orthogonal to the mounting plane, may be applied, for example, on a projection or a step of the blade part in this region whereas the driving force of the cutting tool acts, for example, upon a distant lateral edge of the cutting tool. A surface normal of the lateral edge preferably is directed parallel to the mounting plane of the cutting jaw in this case.
According to another potential embodiment, which is of particular interest for cutting tools with a blade part that is immovably connected to an associated cutting jaw, the blade part may comprise a first partial region having the blade edge and a second partial region, which is connected to the cutting jaw and on which the first partial region is pivotably supported, wherein the intersecting point between the counterholding force of the cutting jaw and the driving force of the cutting tool defines a pivoting center, about which the first partial region can be pivoted relative to the second partial region and which lies outside the line of action of the cutting force of the blade part acting upon the workpiece to be cut. According to this embodiment, the blade part itself is composed of at least two parts, wherein a first and a second partial region are pivotably connected to one another such that the first partial region having the blade edge can be pivoted into the cutting plane. In this case, the connection between the first partial region and the second partial region may be produced, for example, by means of a screw that allows the pivoting movement of the first partial region relative to the second partial region. The screw or screws for fastening the first partial region on the second partial region are not firmly tightened in this case, but rather allow the aforementioned pivotability, wherein it may be preferred to bond the screws to the partial regions in order to limit the pivotability in a reproducible manner. According to this embodiment, the intersecting point between the counterholding force applied to the stationary second partial region and the driving force also lies outside the line of action of the cutting force of the blade part such that a torque is generated, wherein said torque pivots the pivotable first partial region about the pivoting center, the location of which preferably is identical to the intersecting point of the counterholding force and the driving force, such that the first partial region tilts in the direction of the cutting plane of the blade part.
The cutting tool may be designed in such a way that the cutting jaws are pivotably supported on a common axis of rotation. This design particularly is used in hand-operated cutting tools. At least one cutting jaw, but preferably both cutting jaws, can be pivoted about a common axis of rotation formed on the tool body in this case.
Alternatively, the cutting tool may be designed in such a way that at least one blade part is supported on the associated cutting jaw of the cutting tool in a linearly displaceable manner and the blade parts therefore can be displaced toward one another essentially parallel to the cutting plane. This design is particularly suitable for automatic cutting systems, but also for hand-operated cutting tools, in which the blade parts should be moved toward one another in the form of a linear movement.
The cutting jaws ultimately may be connected to the tool body in a separable manner. According to this embodiment, the cutting tool may be realized in the form of a universal tool that can accommodate different blade parts, but also other tool attachments, e.g., for bending, punching or crimping. Such an embodiment is also particularly advantageous in tools that carry out a large number of work processes and therefore require a frequent change of the tool attachment.
The invention is described in greater detail below with reference to exemplary embodiments. In the drawings:
The blade parts 9, 10 are during a cutting process guided by means of a tongue and groove guide referred to the direction of displacement of the lower blade part 9. This is illustrated in
The blade parts 9, 10 are supported in the associated cutting jaw 2, 3 in such a way that a counterholding surface 39, 40 of the respective blade part 9, 10 is supported against a mounting contact region 18, 19 of the cutting jaw 2, 3, which is formed in a mounting plane 5, 6. In this case, a counterholding force FH, which is described in greater detail below with reference to
a show an embodiment of a cutting tool 1 according to the prior art. These figures serve for elucidating the forces that act while a workpiece 12 is cut.
In order to avoid this problem, an inventive cutting tool 1 is proposed, in which the cutting gap 14 between the blade edges 7, 8 of the cutting tool 1 is prevented from forming or increasing.
In the embodiment according to
A cutting tool, which is characterized in that that the end 41 facing the cutting plane 11 defines the first distance 37 and that the first distance 37 and/or the second distance 38 are chosen in such a way that the intersecting point 15 lies in front of the line of action 13 of the cutting force FSchn referred to a clockwise direction.
A cutting tool, which is characterized in that the end 41 facing the cutting plane 11 defines the first distance 37, in that the first distance 37 corresponds to one-tenth or more of an orthogonal distance between the mounting planes 5, 6 or the second distance 38 corresponds to one-tenth or more of an orthogonal distance between the mounting planes 5, 6 or the first distance 37, as well as the second distance 38, corresponds to one-tenth or more of an orthogonal distance between the mounting planes 5, 6, and in that the intersecting point 15 lies in front of a line of action 13 of a cutting force FSchn, which acts upon the blade parts 9, 10 during a cutting process for cutting a workpiece 12, referred to a clockwise direction.
A cutting tool, which is characterized in that the blade edge 7, 8 is pivotable to such a degree that a cutting gap 14 formed between the blade parts 8, 10 while cutting the workpiece 12 is at least reduced, wherein the cutting gap 14 particularly is closed in that the first blade edge 7 of the first blade part 9 contacts the second blade edge 8 of the second blade part 10.
A cutting tool, which is characterized in that the blade part 9, 10 is pivotably supported on the associated cutting jaw 2, 3 or that a first partial region 20 of the blade part 9, 10 with a blade edge 7, 8 is pivotably supported on a second partial region 21 of the blade part 9, 10, which is immovably connected to the cutting jaw 2, 3, or that the cutting jaw 2, 3 carrying the blade part 9, 10 is pivotably supported on the tool body 4 of the cutting tool 1.
A cutting tool, which is characterized in that the blade part 9, 10 is designed in such a way that the counterholding surface 39, 40 of the blade part 9, 10, which is acted upon with the counterholding force, and the application surface 33, 34 of the blade part 9, 10, which is acted upon with the driving force FA, are outwardly spaced apart from the cutting plane 11 by such a distance that their intersecting point 15 lies outside the line of action 13 of the cutting force FSchn of the blade part 9, 10 acting upon the workpiece 12 to be cut.
A cutting tool, which is characterized in that the counterholding surface 39 of the first blade part 9, which is acted upon with the counterholding force FH, is with respect to a direction extending parallel to the mounting plane 5 offset relative to the application surface 33 of the first blade part 9, which is acted upon with the driving force FA, in the direction of the second blade part 10 by such a distance that the intersecting point between the counterholding force FH and the driving force FA lies outside the line of action 13 of the cutting force FSchn of the blade part 9 acting upon the workpiece 12 to be cut.
A cutting tool, which is characterized in that the blade part 9, 10 comprises a first partial region 20 with the blade edge 7, 8 and a second partial region 21, which is connected to the cutting jaw 2, 3 and on which the first partial region 20 is pivotably supported, wherein the intersecting point 22 between the counterholding force FH of the cutting jaw 2, 3 and the driving force FA of the cutting tool 1 defines a pivoting center 23, about which the first partial region 20 can be pivoted relative to the second partial region 21 and which lies outside the line of action 13 of the cutting force FSchn of the blade part 9, 10 acting upon the workpiece 12 to be cut.
A cutting tool, which is characterized in that the cutting jaws 2, 3 are pivotably supported on a common axis of rotation 24.
A cutting tool, which is characterized in that at least one blade part 9, 10 is supported on the associated cutting jaw 2, 3 of the cutting tool 1 in a linearly displaceable manner such that the blade parts 2, 3 can be displaced toward one another essentially parallel to the cutting plane 11.
A cutting tool, which is characterized in that the cutting jaws 2, 3 are separably connected to the tool body 4.
Number | Date | Country | Kind |
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10 2021 105 427.3 | Mar 2021 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2022/055757 | 3/7/2022 | WO |