Knife

Abstract

The invention relates to a knife with a holder (11) and with a blade device (12) which is movable relative to the holder (11) between a safety position and a cutting position by means of a handle (16a, 16b) being movable between an inactive position and an active position. The special feature is that the holder (11) provides a contact surface (21) for an actuating finger (18) within the range of the movement path of the handle (16a, 16b), with which the handle (16a, 16b) is actuated.

Description

[0001] The invention relates to a knife.

[0002] The knife comprises a holder, for example, a housing-like structure, within which a blade assembly is movable between a safety position and a cutting position. In the safety position, the blade's cutting edge is concealed by the housing, thus preventing injury to the user. In the cutting position, a portion of the cutting edge protrudes from the housing, allowing a cut to be made. A handle, movable between an inactive and an active position, allows the blade assembly to be moved from the safety position to the cutting position.

[0003] Such a knife is known from EP 3 112 099 A1.

[0004] In the knife described above, to avoid interfering with the automatic retraction function of the blade holder's return mechanism and thus compromising the knife's safety, the handle is released as soon as the blade enters the material being cut. This movement of the blade into the cutting position and holding it in that position then prevents the blade from entering the cutting position. The frictional force between the blade and the material being cut then holds the blade in the cutting position against the force of the return mechanism. It has been found that the thumb position after releasing the handle is tiring for the user.

[0005] Furthermore, knives are known from the prior art in which the blade assembly can be moved into the cutting position by means of the handle, but the blade assembly can automatically return to the safety position after a cutting operation, even if the handle is in the active position. However, in order to move the blade assembly back into the active position, the handle must first be moved into the inactive position. Therefore, even with these knives, the user must release their operating finger from the handle.

[0006] It has been shown that these movements of the operating finger lead to user fatigue if they are performed frequently.

[0007] The purpose of the invention was to create a knife that reduces fatigue in the operating finger.

[0008] The problem was solved by a knife having the features of claim 1.

[0009] The knife according to the invention comprises a holder and a blade assembly. The blade assembly is, for example, a blade with an edge or a blade holder in which a blade with an edge can be mounted, for example, detachably. The blade assembly is movable relative to the holder between a safety position and a cutting position. The blade assembly can be moved from the safety position to the cutting position by moving a handle, which is movable between an inactive position and an active position, from the inactive position to the active position.

[0010] The holder includes a contact surface for the operating finger within the reach of the handle's path of movement. This contact surface is separate from any operating surface of the handle and is fixed relative to the holder.

[0011] The user can thus remove their operating finger from the handle and place it on the contact surface, preventing rapid fatigue. This ensures the blade mechanism retracts. The operating finger can still guide the blade against the contact surface and, for example, cause it to rotate. Because the contact surface is within easy reach of the handle, the user can quickly move their operating finger back onto the handle.

[0012] The blade assembly is, for example, biased into the safety position by a return mechanism. When there is no longer a counterforce to the return force of the return mechanism, the blade assembly is moved back into the safety position. The knife thus provides a safety function that automatically returns the blade to the safety position when the handle is relieved of pressure, or, in the case of knives with automatic blade retraction where a clutch between the blade assembly and the handle can be disengaged, when the blade is automatically returned to the safety position.

[0013] The holder is, for example, at least partially designed as a housing. The blade can then be retracted into an interior of the housing in the safety position, thus protecting the user from contact with the cutting edge. Other moving parts can also be enclosed within the housing, preventing user injury. The housing can provide storage space for spare parts or accessories. Furthermore, the housing can also incorporate an ergonomic handle.

[0014] The contact surface is, for example, designed parallel to a sagittal plane of the knife. For the purposes of the invention and in accordance with common usage, a sagittal plane is defined as a vertically extending plane that passes through a longitudinal center axis of the holder. Typically, at least one handle is arranged on one side of the holder, e.g., a housing. For example, a handle can be arranged on each of the opposite sides of the holder.

[0015] The contact surface is positioned on the housing, for example, so that it is within reach of the handle and the user's finger can easily move from the handle to the contact surface. For instance, the contact surface is arranged so that—when the handle is in the active position—the user's finger only has to make the shortest possible movement from the handle to the contact surface. By arranging the contact surface parallel to the sagittal plane, the user's finger only needs to perform a pivoting motion and not a torsional one.

[0016] Alternatively, the contact surface can be positioned approximately midway between the handle's position in the safety position and the cutting position. This allows easy access to the contact surface from all handle positions. In certain cutting applications, the blade may not extend beyond its maximum length. This is the case, for example, when the cutting depth is less than required. Therefore, a contact surface position that allows easy access from intermediate handle positions is advantageous.

[0017] The contact surface is located, for example, below the handle. In this case, the user can simply lower their operating finger onto the contact surface. This position of the contact surface is also advantageous for ergonomic reasons.

[0018] The contact surface is formed, for example, on a projection of the housing. In this case, the contact surface only slightly increases the size of the holder. The visual appearance and handling of the knife are not affected by the projection. The projection can, for example, be manufactured as a single piece with the knife housing. It can be produced, for example, as a single piece with the holder using plastic injection molding or die casting. Furthermore, the projection facilitates rotation of the holder around its central axis.

[0019] For example, the contact surface has a depression that is at a different level than an adjacent area. The height differs, for instance, in a direction perpendicular to the sagittal plane. Because of these different heights, the operating finger can intuitively feel its target position on the contact surface and quickly assume it. The difference in height also prevents the operating finger from slipping off the contact surface, as the raised area acts as a boundary.

[0020] The transition to the adjacent area is formed, for example, by a ramp between the recessed level and the adjacent level. The operating finger can then be moved smoothly from the level corresponding to the handle's operating surface to the recessed level without abrupt or unergonomic transitions.

[0021] The surface of the contact area, for example, forms a structure, at least in some areas, that provides grip for the actuating finger. This structure makes it more difficult for the actuating finger to slide relative to the contact area. This promotes a relaxed placement of the actuating finger on the contact area.

[0022] The length of the contact surface is, for example, greater than its width, corresponding to the longitudinal extent of the fingertip. Since the longitudinal extent of the fingertip of the operating finger contacts the contact surface according to its longitudinal extent, it is advantageous if this surface is formed by an area whose longitudinal extent is large in relation to its width, e.g., twice as large.

[0023] For example, a handle and a contact surface are formed on opposite sides of the holder. The knife can then be used by both right-handed and left-handed people.

[0024] The holder can be made of, for example, plastic, a plastic composite such as fiber-reinforced plastic, or a cast metal.

[0025] Exemplary embodiments of the invention are described in the following description of the figures, also with reference to the drawings. For the sake of clarity, identical or comparable parts, elements, or areas are designated with the same reference numerals, sometimes with the addition of lowercase letters, even where different embodiments are concerned.

[0026] Features described only in relation to one embodiment can also be provided in any other embodiment of the invention. Such modified embodiments are included in the invention, even if they are not shown in the drawings.

[0027] All disclosed features are essential to the invention. The disclosure of this application hereby incorporates in full the disclosure content of the cited publications and the described devices of the prior art, also for the purpose of including one or more features of these documents in one or more claims of the present application.

[0028] The schematic figures show: Fig. 1 a side view of a prior art knife, wherein the blade device is arranged in the cutting position, Fig. 2 a side view of a knife according to the invention, wherein the blade device is arranged in the safety position, Fig. 3 a side view of a knife according to the invention, wherein the blade device is in the cutting position and an actuating finger is located on an actuating surface of the handle, Fig. 4 a side view based on Fig. 3 , wherein the blade is in contact with the cutting material and the actuating finger rests against the contact surface, Fig. 5 a side view based on Fig. 2 , wherein the blade device is in the safety position and the actuating finger rests against the contact surface, Fig. 6 a view according to view arrow A in Fig. 2 , Fig. 7 a sectional view according to section line B - B in Fig. 6 , Fig. 8 a perspective view of the knife, with the blade device arranged in the safety position, Fig. 9 a perspective view of the knife according to Fig. 8 , wherein the blade device is arranged in the cutting position, Fig. 10 a side view of the knife from a perspective relating to Fig. 2 opposite side Fig. 11 a perspective view of the knife according to Fig. 10 from a rear angle.

[0029] Fig. 1 Figure 110 shows a prior art knife. The knife comprises a holder 111 in which a blade device 12, here comprising a blade carrier 13, and a blade 14 are movable between a safety position and a cutting position.

[0030] The holder 111 comprises lateral recesses 29a and 29b on opposite flank surfaces 31a and 31b of the holder 111, of which in Fig. 1 Only the recess 29a is visible. The recesses 29a and 29b allow the user to insert the blade device 12 into the recess using a handle 16. Fig. 1 to move to the cutting position shown. Since the recesses 29a and 29b are formed on both flank surfaces 31a and 31b of the holder 111, the knife can be operated by right-handed or left-handed persons.

[0031] In the cutting position, a section of a cutting edge 20 of the blade device 12 emerges from an opening 15 of the holder 111 and a cutting operation can be carried out. Fig. 1 Figure 1 shows a cutting position in which the cutting edge 20 is moved maximally out of the holder 111 and a stop of the blade assembly 12 is in contact with a surface of the holder 111. It is also possible to move the blade assembly 12 only far enough in the direction x1 that the cutting edge 20 emerges from the holder 111 at a shorter length.

[0032] For movement, the handle 16a has an actuation surface 17, which is connected to an actuation finger 18 (in Fig. 1 (not shown) can be contacted and moved. The blade device 12 is biased into the safety position by means of a return mechanism 19. That is, when the handle 16a is released, the blade device 12 is moved back into the safety position by the return force of the return mechanism 19 in direction x2, in which the cutting edge 20 is moved back into the holder 111 in such a way that the user cannot come into contact with the cutting edge 20.

[0033] The automatic blade retraction safety function is only possible if the user relieves the blade assembly 12, i.e., does not hold it in the cutting position against the spring force acting in direction x2. Therefore, the user must release the actuating finger 18 from the handle 16a after the blade 14 has made contact with the material being cut, and the blade 14 has been held in the cutting position against the spring force by the frictional force between the blade 14 and the material being cut. This process occurs many times when working with the knife 110, which led to fatigue of the actuating finger 18.

[0034] The knife according to the invention as a whole is in the Fig. 2 bis 11 designated with reference numeral 10.

[0035] The knife 10 is in Fig. 2 The blade assembly 12 is shown in the safety position. It is retracted into a receiving chamber 33 of the holder 11. Injury to the cutting edge 20 is then impossible. Against the force of a resetting device 19 acting in direction x2, the blade assembly 12 can be moved from the safety position, corresponding to the prior art knife 110, by means of the handle 16 in direction x1 into a cutting position, which is shown in Fig. 3 As shown. In the cutting position, a cutting edge 20 of the blade device 12 emerges from the housing-like holder 11 and a cutting process is possible.

[0036] The knife 10 according to the invention Fig. 2 bis 7 The holder 11 differs from the prior art knife 110 only in that it has contact surfaces 21a and 21b for the actuating finger 18 for actuating the handles 16a and 16b. The contact surfaces 21a and 21b are provided to prevent the rapid fatigue of the actuating finger described above, by allowing the actuating finger 18 to be placed on the contact surface 21a or 21b after contact has been established between the blade device 12 and the cutting material 30, and to remain there until a new cutting operation is performed.

[0037] The knife 10 described here is suitable for both right- and left-handed users and therefore has recesses 29a and 29b, handles 16a and 16b, and support surfaces 21a and 21b. Alternatively, the knife 10 could also be equipped with only one handle 16a for right-handed users or one handle 16b for left-handed users. In this case, the knife 10 would also only have one support surface 21a or 21b.

[0038] In Fig. 2 A sagittal plane E of the knife 10 is shown, which runs through a longitudinal central axis m of the knife 10. The contact surfaces 21a and 21b are approximately parallel to the sagittal plane E and parallel to the actuating surface 17 of the handles 16a and 16b. The length 11 of the contact surfaces 21a and 21b is, for example, twice as long as their width B. A side region of the fingertip of the actuating finger 18 can thus rest against the contact surface 21a or 21b.

[0039] In Fig 2 It can be seen that the contact surface 21a is recessed relative to the adjacent outer surface 26a of the holder 11. The transition from the outer surface 26a to the contact surface is formed by a ramp 27. The ramp 27 prevents the actuating finger 18 from slipping off the contact surface 21a. Furthermore, the contact surface 21a can be easily located by touch due to the recessed contact surface 21a and the ramp 27. The contact surface 21b (see the Fig. 10 und 11 ) is designed in the same way as the mounting surface 21a. It is also designed as a recess with ramp 27. The mounting surfaces 21a and 21b can also have a structure 32 which prevents the actuating finger 18 from slipping.

[0040] In the knife 10 of this described embodiment, recesses 29a and 29b are formed on both flank surfaces 31a and 31b, through which a handle 16a and 16b can be actuated. Furthermore, contact surfaces 21a and 21b are also formed on both flank surfaces 31a and 31b of the projection 28.

[0041] The knife 10 comprises a top surface 22, a bottom surface 23, a front end 24, and a rear end 25. In this embodiment, the contact surfaces 21a and 21b are formed on the projection 28 on the bottom surface 23 of the holder 11. The user can then ergonomically and advantageously lower the operating finger 18 from the handle 16 onto the contact surface 21a or 21b. Fig. 2 A central area of ​​the contact surface 21a is spaced a distance h away from a central area of ​​the actuating surface 17. The distance h is chosen such that the contact surface 21a is within reach of the actuating finger 18, which actuates the actuating surface 17.

[0042] The following describes an example of operation at the handle 16a. Starting from the state of the safety position of the blade device 12 according to Fig. 2 The user can move the handle 16a with the actuating finger 18 on the actuating surface 17, thereby increasing the potential energy of the return device 19, which loads the blade device 12 in direction x2, in the direction x1, until the cutting edge 20 of the blade device 12 emerges from the opening 15 at the front end 24 of the holder 11. A cutting position in which the blade device 12 is moved maximally in direction x1 is in Fig. 3 The cutting edge 20 can alternatively be moved into a cutting position in which the cutting edge 20 protrudes from the holder 11 with a shorter length l2. The length l2 denotes the length by which the cutting edge 20 projects beyond the holder 11 (see Fig. 3 ).

[0043] The return mechanism 19 applies a force to the blade assembly 12 in direction x2. Before the cutting process, the user must hold the blade assembly 12 in the cutting position against the force of the return mechanism 19. When the blade assembly 12, here the blade 14, is in contact with a cutting material 30 (see Fig. 4 ) the frictional force between the cutting material 30 and the blade device 12 prevents a movement of the blade device 12 in direction x2 caused by the reset device 19.

[0044] The actuating finger 18 can then be used according to Fig. 4 The actuating finger 18 is moved from the operating surface 17 of the handle 16a and onto the support surface 21a. This ensures the safety function, which, upon completion of the cutting process or in the event of an unintentional sudden exit of the blade device 12 from the cutting material 30, retracts the cutting edge 20 into the holder 11 in the safety position. When the handle 16a is released, the actuating finger 18 does not need to be spread away from the holder 11, but can be positioned relaxed on the support surface 21a.

[0045] The positioning of the actuating finger 18 on the contact surface 21a is also advantageous for guiding the knife 10 and thus the cut. Due to the projection 28, which is spaced apart from the central axis m and on which the contact surfaces 21a and 21b are formed, it is possible to exert a force in the direction of rotation about the central axis m of the holder 11 with a lever arm h.

[0046] According to Fig. 5 After the blade 12 leaves contact with the cutting material 30, it moves into the safety position. The actuating finger 18 remains in contact with the contact surface 21a. Only when the handle 16a is actuated again into the cutting position does the actuating finger 18 move back onto the actuating surface 17.

[0047] In Fig. 6 A top view of the upper surface 22 of the knife 10 is shown.

[0048] In Fig. 7 The receiving space 33 of the housing-like holder 11 is visible. The blade assembly 12 is movably guided in the receiving space 33. It can be seen that the return mechanism 19 in this example comprises a spring which is attached to the blade assembly 12, here to the blade carrier 13, as well as to the holder 11, and which is tensioned when moving from the safety position to the cutting position. In this example, the return mechanism 19 comprises only one spring; alternatively, however, several springs or other return mechanisms could also be present to compress the blade assembly 12 into the safety position. In the sectional view according to Fig. 7 The blade 14 is not visible. A seating surface 34 for the blade 14 is visible, which has a positive locking means 35 and a magnet 36 for holding the blade 14.

[0049] The Fig. 8 und 9 show perspective views of knife 10 in the safety position ( Fig. 8 ) and in the cutting position ( Fig. 9 ).

[0050] Fig. 10 shows a side view of the knife 10, where the flank surface 31b is formed by a Fig. 2 as can be seen on the opposite side of the holder 11 shown. According to Fig. 10 The length l1 of the mounting surface 21b is approximately twice as long as its width B.

[0051] In Fig. 11 is a perspective view of this in Fig. 10 The page shown is depicted. From the Fig. 10 und 11 It becomes clear that the recess 29b allows the operation of a handle 16b. The knife 10 can therefore be operated by both right- and left-handed users. In the Fig. 10 und 11 It can also be seen that the projection 28 also provides a loading area 21 b for a user with left-hand operation, which is designed in the same way as the loading area 21a, recessed and equipped with a ramp 27.

[0052] The holder 11 of the knife 10 and / or the blade carrier 13 can be made of plastic or alternatively of a metal casting.

[0053] In this embodiment, the blade 14 is a strip steel blade that can be detached from the blade holder 13 and replaced by another blade 14. For this purpose, the housing-like holder 11 is designed in two parts so that it can be opened.

Claims

1. Knife with a holder (11) and with a blade device (12) which is movable relative to the holder (11) between a safety position and a cutting position, in that at least one handle (16a, 16b) is movable between an inactive position and an active position, characterized by the fact that The holder (11) provides a contact surface (21) for an actuating finger (18) within the range of the movement path of the handle (16a, 16b), with which the handle (16a, 16b) is actuated.

2. Knife according to claim 1, characterized by the fact that the holder (11) is designed as a housing.

3. Knife according to any of the preceding claims, characterized by the fact that the blade device (12) is loaded into the safety position by a resetting device (19).

4. Knife according to any of the preceding claims, characterized by the fact that the mounting surface (21a, 21b) is formed parallel to a sagittal plane (E) of the knife (10).

5. Knife according to any of the preceding claims, characterized by the fact that the mounting surface (21a, 21b) is formed on a projection (28) of the holder (11).

6. Knife, characterized by according to one of the preceding claims, that the contact surface (21a, 21b) is located approximately midway between the position of the handle (16) in the safety position and in the cutting position.

7. Knife according to any of the preceding claims, characterized by the fact that the mounting surface (21) is arranged as a depression which has a lowered level in relation to an adjacent outer surface (26) of the holder (11).

8. Knife according to any of the preceding claims, characterized by the fact that the transition from the facility area (21) to the adjacent outdoor area (26) has a ramp (27).

9. Knife according to any of the preceding claims, characterized by the fact that the mounting surface (21a, 21b) forms at least in some areas a structure (32) which provides support for the actuating finger (18).

10. Knife according to any of the preceding claims, characterized by the fact that a length (11) of the surface area (21) is greater than its width (B).

11. Knife according to any of the preceding claims, characterized by the fact that On opposite flank surfaces (31a, 31b) of the holder (11) a handle (16a, 16b) and a contact surface (21a, 21b) are formed.

12. Knife according to any of the preceding claims, characterized by the fact that the holder (11) is at least partially made of a plastic, a composite plastic or a metal casting.

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