Messer

Abstract

A knife comprising a housing (11) and a blade holder (13) movable within the housing (11) between a rear position, a cutting position, and a blade change position, comprising a return device (34) with which the blade holder (13) can be loaded into the rear position relative to the housing, the return device comprising a spring (35) and a movable element, wherein the movable element is connected to a spring end of the spring (35) and is loaded by the spring end in a direction of movement, characterized in that the return device (34) is mounted on the housing (11) or the blade holder (13) and the movable element is in contact with a counter surface of the respective other part with respect to the housing (11) or blade holder (13), wherein the counter surface comprises differently oriented surface areas (43, 44, 45, 43', 44', 45') with which the movable element interacts depending on the position of the blade carrier.wherein the movable element interacts with the blade holder (13) and with the housing (11) and loads the blade holder (13) in at least one region of the movement of the blade holder (13) into the rear position.

Description

[0001] The invention relates to a knife. Such a knife is known from DE 10 2016 008 724 A1. It comprises a housing and a blade holder movable within the housing between a rear position and a cutting position. A return device in the form of a spring biases the blade holder into the rear position. In the rear position, the blade is retracted far enough into the housing that the user cannot come into contact with the cutting edge and therefore cannot injure themselves. In the cutting position, the blade protrudes from a front opening in the housing, enabling a cutting operation.

[0002] The knife according to DE 2011 007 234 B3 comprises a movable element (coupling element) which is spring-loaded (see paragraphs 15 and 18 of DE 2011 007 234 B3). According to paragraph 15, the coupling element is provided for decoupling the actuation and the blade carrier. The spring can be arranged in such a way that decoupling is promoted or inhibited. Upon the action of a cutting reaction force, the blade is thus decoupled from the actuation and is retracted by the spring when the force on the blade decreases, even though the actuation is still actuated. A safety element (see paragraph 20) can be provided to prevent re-coupling.

[0003] The knife according to DE10 2010 023 680 A1 comprises a blade holder 12 and an actuating element 19. The actuating element is spring-loaded in the retraction direction x2. The connecting device 17 can be moved between a stable and an unstable position (see the Fig. 1a and Fig. 3a). In the unstable position, the blade carrier can move into a safety position despite the actuation (see Fig. 4a).

[0004] The object of the invention was to design the reset device in such a way that it could be manufactured cost-effectively. Furthermore, the reset device should allow for easy assembly of the knife. Furthermore, the reset device should be designed so that the reset force can be varied by simply changing the design.

[0005] The problem was solved by a knife having the features of claim 1.

[0006] The knife comprises a housing and a blade holder movable within the housing between a rear position and a cutting position. The knife also includes a return device with a spring that can be used to force the blade holder into the rear position relative to the housing.

[0007] The housing may comprise several parts. In particular, if these parts are immovable relative to other housing parts and firmly connected to them, they will be referred to below as the "housing."

[0008] The return device is mounted on the housing or on the blade holder and comprises a movable element connected to a spring end and loaded by the spring end in a direction of movement. The movable element interacts with the blade holder and the housing and loads the blade holder toward the rear position at least within a range of movement of the blade carrier.

[0009] The movable element has, for example, a contact surface that is in contact with a mating surface of the housing or with the blade holder. For example, if the reset device is mounted on the blade holder, the contact surface is in contact with the housing. If the reset device is mounted on the housing, the contact surface is in contact with the blade holder.

[0010] The contact surface can be formed, for example, on a projection of the movable element.

[0011] The spring is designed, for example, as a compression spring or a tension spring. Such springs are available inexpensively in various sizes. Tension springs, in particular, are easy to store and attach to the components to be loaded.

[0012] For the purposes of the invention, a spring is any device made of an elastically deformable material that exerts a restoring force after deformation. As long as this property is met, the term is independent of the shape and material of the device. The spring can be made of spring steel, a plastic, or a natural material, for example.

[0013] The movable element interacts, for example, with differently aligned surfaces of the housing or the blade holder, which form the counter surface. The orientation of the surface is subsequently specified with the direction of the surface orthogonals. For example, when the blade carrier moves between the rear position and the cutting position, the movable element can be in contact with a counter surface, which loads the blade carrier into the rear position. In the blade change position, the movable element can be in contact with a counter surface in such a way that the blade carrier is not loaded in the retraction direction or is only loaded with a small force, so that no movement takes place. This can be the case, for example, if the blade carrier is loaded in a direction in which it has no degree of freedom.

[0014] A first surface, e.g., a surface of the blade carrier or the housing that is in contact with the movable element, is oriented, for example, relative to the direction of movement of the blade holder in such a way that the blade holder is biased toward the rear position. The surface orthogonal is oriented, for example, parallel to the direction of movement of the blade holder or has portions that are oriented in this manner.

[0015] A second surface, e.g. a surface of the blade carrier or the housing that is in contact with the movable element, is oriented in such a way to the direction of movement of the blade holder that the blade holder is not loaded into the rear position or is loaded with less force. The surface orthogonal is oriented, for example, at right angles to the direction of movement of the blade holder or has portions that are oriented in this way. If the surface orthogonal is oriented at right angles to the direction of movement of the blade holder, the movable element cannot transfer any force to the blade holder in the direction of the rear position. Therefore, the blade holder remains in the set position. In this case, a portion of the spring force is directed in a direction other than the retraction direction and is e.g. absorbed by the housing.

[0016] The counter surface is designed, for example, as a control surface that is moved by the movable element when the blade carrier moves between the rear position and the blade change position. At least two differently aligned surfaces are formed, for example, on a counter surface. In this case, the return device is mounted on the housing or the blade holder and the counter surface on the other part, i.e. the blade holder or the housing. A guide element of the movable element can be guided on the counter surface. Depending on the orientation of the counter surface with which the movable element is in contact, the blade holder is loaded into the rear position, loaded with less force into the rear position, or not loaded into the rear position at all.

[0017] The movable element is formed, for example, by a lever, e.g., a two-armed lever. The lever can pivot about a fixed pivot axis or about a movable pivot axis. One lever arm, for example, encompasses the contact surface. A second lever arm, e.g., is spring-loaded.

[0018] For example, the spring and the movable member are attached to the blade holder, with one end of the spring being connected to the blade holder and another end of the spring being connected to the movable member.

[0019] Alternatively, the spring and the movable element are fixed to the housing and one spring end of the spring is connected to the housing and another spring end is connected to the movable element.

[0020] The housing is equipped with at least one first stop, and the blade holder is equipped with a counter-stop. The contact between the stop and counter-stop determines the cutting position. This means that the blade holder can only be moved from the rear position toward the cutting position until the stop and counter-stop are in contact, thus determining the cutting position.

[0021] For example, the housing is equipped with a second stop, which is in contact with the counter-stop in a blade-change position and prevents further movement in the direction opposite to the rear position. In the blade-change position, the blade carrier is moved beyond the cutting position relative to the rear position.

[0022] For example, a stop on the housing that defines the cutting position can be reached via a first movement path, and a stop that defines the blade change position can be reached via a second movement path. For example, a region of the blade carrier is mounted so that it can be moved flexibly that the counter-stop can be moved between the first movement path and the second movement path. The counter-stop can be moved between the movement paths, for example, by means of an actuation. If the counter-stop then moves along the first movement path, the movement is limited by the first stop; if the counter-stop moves along the second movement path, the movement is limited by the second stop.

[0023] The first movement path and the second movement path can be separated from each other by a wall such that the counter-stop cannot move between the first movement path and the second movement path—at least in one movement range. For example, the counter-stop can be moved between the first movement path and the second movement path in the rear position.

[0024] An embodiment of the invention is described by way of example in the following description of the figures, also with reference to the schematic drawings. For the sake of clarity, identical or comparable parts, elements, or regions are designated by identical reference numerals, sometimes with the addition of lowercase letters or apostrophes.

[0025] Features that are described, illustrated or disclosed only with reference to one embodiment may also be provided in any other embodiment of the invention within the scope of the invention.

[0026] The schematic figures show: Fig. 1, a side view of the fully assembled knife with the blade holder in a rear position, Fig. 2 based on Fig. 1 the knife, with the blade holder in a cutting position, Fig. 3 based on Fig. 1 the knife, with the blade holder in a blade change position and a blade cover pivoted away from the blade seat, Fig. 4 a side view of the knife according to Fig. 1, where a housing part is not shown, Fig. 5 a side view of the knife according to Fig. 2, where a housing part is not shown, Fig. 6 a side view of the knife according to Fig. 2, whereby one housing part is not shown. Fig. 7 a sectional view according to section line A - A in Fig. 4, Fig. 8 a section view according to section line B in Fig. 6, Fig. 9 a front view according to arrow C in Fig. 1, Fig. 10 a side view of a second embodiment of the knife based on Fig. 4 in the rear position, wherein the return device is formed on the blade holder and the counter surface on the housing, Fig. 11 a side view of the second embodiment in accordance with Fig. 5 in the cutting position, Fig. 12 a side view of the second embodiment in accordance with Fig. 6 in the blade change position.

[0027] The knife as a whole is designated by reference number 10 in the figures.

[0028] A first embodiment of the knife 10 comprises according to Fig. 1, a housing 11 with a first housing part 12 and a second housing part 23. Furthermore, the knife 10 comprises a blade holder 13 with a blade 14 provided with a cutting edge 25. In the present embodiment, the housing part 23 is designed as a sleeve and includes a front opening 15 and a rear opening 16. A longitudinal center axis of the knife 10 is designated by m.

[0029] For actuating the blade holder 13, recesses 17a and 17b are also formed on both sides of the housing part 23 at a front end region 18 of the knife 10. At a rear end region 19 of the knife 10, two recesses are provided in the housing part 23, one of which forms a recess 20 for actuating an actuating element 21, and another recess 22 forms a through-opening that serves for suspending the knife 10.

[0030] In the present embodiment, the housing part 23 is formed from a sheet metal part, but it can also be made of other materials and have a different shape. The material and external shape of the housing are not important for the invention, as will become clear below.

[0031] According to Fig. 1, the blade holder 13 is in the rear position. By gripping the blade holder 13 through the recesses 17a and 17b, the blade holder 13 can be displaced relative to the housing 11 from the rear position in the direction x1 into a cutting position which is Fig. 2. When the force on the blade holder 13 decreases, the blade holder 13 is automatically moved to the rear position by a return device 34 if it is in a position between the rear position and the cutting position, including the cutting position.

[0032] To prevent the fingers from slipping, the blade holder 13 has a structure 24 on both sides of its front end area, which gives the fingers a good grip.

[0033] In addition, the blade holder 13 has an oblique recess 26 through which a portion of the cutting edge 25 of the blade 14 is exposed. In the present embodiment, the knife 10 has a rectangular blade 14, but in principle, any blade shape, such as a trapezoidal blade, a hooked blade, etc., can be used.

[0034] In Fig. 1 it can also be seen that the housing part 23 forms beads 54 which form recesses in the interior of the housing part 23 into which the housing part 12 can be locked.

[0035] According to Fig. 3, the blade holder 13 is moved beyond the cutting position in the direction x1 into a blade change position. The blade carrier 13 can only be moved beyond the cutting position if the actuating element 21 has previously been actuated. The blade holder 13 comprises, in a known manner, a base part 27 in which a blade seat 29 is formed, as well as a cover part 28, which forms a pivot joint G1 with the base part 27. The blade 14 is held between the base part 27 and the cover part 28. In the blade change position, it is possible to pivot the cover part 28 about a pivot axis a1 away from a blade seat 29 from a closed position according to the Fig. 1 and Fig. 2 into an open position according to Fig. 3 to swing.

[0036] In Fig. 3 shows that the blade 14 is provided with a slot-shaped opening 30, and the blade seat 29 includes a complementary projection 31 that can pass through the blade 14 and engage a recess 32 in the cover part 28 when the cover part 28 is in the closed position. In this way, the blade 14 can be held in a form-fitting manner in the blade holder 13. When the cover part 28 is in the open position, the blade 14 can be removed from the blade seat 29 and replaced with a new blade 14.

[0037] When the blade holder 13 is located between the rear position and the cutting position, the cover part 28 is held in the closed position by opposite side walls 33a and 33b (not in drawings) of the housing 11.

[0038] Fig. 4 shows the knife 10 without the housing 11, with the blade holder 13 according to Fig. 1 is in the rear position. A return device 34 forces the blade holder 13 into the rear position when the blade holder 13 is in the rear position, the cutting position, or between the aforementioned positions.

[0039] The rear position is defined by the contact between stop shoulders 46 of the blade holder 13 and a surface 47 of the base 12. The return device 34 comprises a spring 35 which is Fig. 5 and Fig. 6 is merely indicated by a dot-dash line. Furthermore, the reset device 34 comprises a lever 36. The spring 35 of the reset device 34 is a tension spring in the form of a helical spring. This spring is connected by one spring end to a spring attachment 37 of the base 12 and by the other spring end to a spring attachment 38 of the lever 36.

[0040] The lever 36 is mounted on the base 12 so that it can pivot about a pivot axis a2 in the directions u1 and u2 and forms a pivot joint G2 with the base 12. The spring 35 loads the lever 36 in the direction u1. In the rear position according to Fig. 4, the spring 35 is subject to preload. The lever 36 comprises a projection 40, which in the present embodiment is designed as a cylindrical pin, but can also have a different shape. An outer surface 41 of the projection 40 is in contact with a counter-surface 42 of the blade holder 13, which in the present embodiment forms a control surface with which, depending on the position of the projection 40, the portion of the spring force of the spring 35 that loads the blade holder 13 in direction x2 can be adjusted.

[0041] The counter surface 42 of the blade holder 13 comprises a surface region 43 whose surface orthogonal is oriented approximately parallel to the movement directions x1 and x2 of the blade holder 13. Furthermore, the counter surface 42 comprises a surface region 45 whose surface orthogonal is oriented approximately perpendicular to the movement directions x1 and x2. A transition region 44 forms an angle of approximately 45° with the region 43 and the region 45. The transition region 44 is arranged between the surface regions 43 and 45 with respect to the movement directions of the projection 40 along the control surface 42.

[0042] During the movement of the blade holder 13 from the rear position according to Fig. 4 into the cutting position according to Fig. 5, the outer surface 41 of the projection 40 rests against the first region 43 of the counter surface 42. Due to the rotational movement of the lever 36, the projection 40 moves from the position according to Fig. 4 about the position in Fig. 5 marked 40" is in the position shown in Fig. 5 is marked 40.

[0043] The cutting position is reached when an extension 49 of the blade holder 13 has moved along a first movement path into contact with a counter surface of a first stop 48 of the base 12.

[0044] If the blade holder 13 is to be moved into a blade change position, the projection 48 can be moved elastically in the direction y1 by means of the actuating element 21 onto a second movement path, which is separated from the first movement path by a wall 55. The blade holder 13 is then moved on the second movement path into the blade change position according to Fig. 6. The movement of the blade holder 13 in direction x1 is limited by the contact of the surface of the extension 49 with a holding surface of a second stop 50. If the blade holder 13 is moved back to the rear position in direction x2, the extension 49 automatically moves back to the first movement path due to its elastic restoring force.

[0045] During the movement of the blade holder 13 between the cutting position and the blade-changing position, the projection 40 slides from the first region 43 over the transition region 44 to the second region 45. The surface orthogonal of the second region 45 is directed perpendicular to the movement directions x1, x2 of the blade holder 13, so that no forces can be transmitted from the lever 36 to the blade holder 13 that would load the blade holder in the direction x2. The blade change can therefore be carried out without the blade holder 13 having to be held in the blade-changing position against the spring force of the spring 35. The spring force is absorbed by the housing part 23 in this position of the projection 40.

[0046] Once the blade change is complete, the blade holder 13 is manually moved from the blade change position relative to the base 12 in the direction x2. The projection 40 then slides in the opposite direction from the area 45 of the counter surface 42 via the transition area 44 to the area 43. Upon reaching the transition area 44, the lever 36 again exerts a force in the direction x2 on the blade holder 13, so that the further movement of the blade holder 13 in the direction x2 until the rear position is reached no longer needs to be actively performed by the user, but occurs automatically due to the restoring force of the spring 35. The rear position is reached when the stop shoulders 46 abut the surfaces 47 of the second housing part 23.

[0047] The knife is assembled as follows, for example. The lever 36 is placed on a pin 51 of the base 12 forming the pivot axis a2. The spring 35 is attached to the lever 36 and to the base 12. The cover part 28 is mounted on the base part 27 of the blade holder 13.

[0048] The blade holder 13 is then inserted into the base 12, and the projection 40 of the lever 36 is brought into contact with the area 45. (Is anything else necessary here to overcome the projection 50?) By further insertion in the direction x2, it comes into contact with the transition area 44, whereupon the blade holder 13 automatically moves to the rear position.

[0049] The assembly of base 12 and blade holder 13 can then be inserted into the rear opening 16 of the housing 11 until a stop surface 52 of the base 12 abuts a rear end surface 53 of the housing 11 and the housing part 12 is locked to the housing part 23.

[0050] The blade 14 can then be mounted by moving the blade holder 13 into the blade change position as described above.

[0051] In the Fig. Figures 10 to 12 show a second embodiment of the knife, which differs from the first embodiment only in that the spring 35' and the lever 36' are formed on the blade holder 13', and the control surface 42' is formed on the housing part 12'. Otherwise, the corresponding components or elements have been provided with the numbers also used in the first embodiment, with these numbers additionally containing an apostrophe.

Claims

[1] Knife with a housing (11) and a blade holder (13) movable in the housing (11) between a rear position, a cutting position and a blade changing position, with a return device (34) with which the blade holder (13) can be loaded into the rear position relative to the housing, which comprises a spring (35) and a movable element, wherein the movable element is connected to a spring end of the spring (35) and is loaded by the spring end in a direction of movement, characterized byin that the return device (34) is mounted on the housing (11) or the blade holder (13) and the movable element is in contact with a counter-surface of the respective other part with respect to the housing (11) or the blade holder (13), wherein the counter-surface comprises differently aligned surface areas (43, 44, 45, 43', 44', 45') with which the movable element interacts depending on the position of the blade carrier, wherein the movable element interacts with the blade holder (13) and with the housing (11) and loads the blade holder (13) in at least one area of ​​the movement of the blade holder (13) into the rear position. [2] Knife according to claim 1, characterized by that the spring (35, 35') is designed as a compression spring or as a tension spring [3] Knife according to one of the preceding claims, characterized bythat the movable element cooperates with at least one counter-surface, wherein a first surface region (43, 43') of the counter-surface is directed towards the direction of movement (x1, x2) of the blade holder (13) in such a way that the blade holder (13) is loaded into the rear position. [4] Knife according to claim 3, characterized in that a second surface area (45, 45') is directed towards the direction of movement (x1, x2) of the blade holder (13) in such a way that the blade holder (13) is not loaded into the rear position. [5] Knife according to one of the preceding claims, characterized by that the counter surface (43, 44, 45, 43', 44', 45') is assigned to a control path which is traversed during the movement of the blade holder (13) between the rear position and the blade change position. [6] Knife according to one of the preceding claims, characterized by that the movable element is formed by a lever (36), in particular a two-armed lever. [7] Knife according to one of the preceding claims, characterized by that the spring (35) and the movable element are attached to the blade holder (13) and that one spring end of the spring (35) is connected to the blade holder (13) and another spring end is connected to the movable element. [8] Knife according to one of the preceding claims, characterized by that the spring (35) and the movable element are fixed to the housing (11) and that one spring end of the spring (35) is connected to the housing (11) and another spring end is connected to the movable element. [9] Knife according to one of the preceding claims, characterized bythat the housing is provided with a first stop (48) and a second stop (50) and the blade holder (13) is provided with a counter-stop (49), wherein the contact of the first stop (48) and the counter-stop (49) defines the cutting position and the contact of the second stop (50) and the counter-stop (49) defines the blade changing position. [10] Knife according to claim 9, characterized by that the counter-stop (49) is movable on a first movement path to the first stop (48) and on a second movement path to the second stop (50). [11] Knife according to claim 10, characterized by that the first movement path and the second movement path are separated by a wall (55) at least in a region of the movement of the counter-stop (49). [12] Knife according to claim 10 or 11, characterized bythat the counter-stop (49) and / or the wall (55) is flexibly mounted such that the counter-stop (49) is movable between the first movement path and the second movement path.

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