DE8021175U1 - TURN KNIFE - Google Patents

Description

Dr _: ..Max.Schneider DA ^: APfdfeijfel

Ernst Czowalla giptlz. Peter Matsch _{cure 01Ρ} ι - _P hy _S

Admitted to the European Patent Office - ag roes pres! 'Office europeen des brevel

85 Nuremberg 106, the 5. August 198 (Königstrasse 1 (Museum Bridge) Telephone collective no. 203931

Q Multi-storey car park Katharlnenhof Multi-storey car park Adlerstrasse

Our toe: 30 422/27-Hi.

Nippon Tenshashi. Kabushiki Kaisha

3-29, Nakano 4-chome, Higashisumiyoshi-ku, Osaka / Japan

"Rotary knife"

The invention is directed to a rotary knife with a cutting unit and a holder, the cutter unit being rotatable relative to the holder.

Rotary knives with a rotatably mounted cutting unit are very useful in order to cut desired cutting patterns from newspapers, Photos or the like. cut out.

This results from the fact that in such cutting operations a cutting tip is moved in such a way that it is curved or follows complicated lines, whereby straight lines are less of a consideration. This process is conventional when using

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Knife very difficult and it is hardly possible to make the desired cutouts to manufacture.

A rotary knife is generally constructed in such a way that the axis of rotation of the cutting unit is eccentric to the cutting tip, so that the cutting tip can be guided in different directions and even complex lines can be traced are.

Basically, two types of rotary knives are known. One of them includes a holding body which is rotatable with the main body is connected, wherein the cutting parts can be exchangeably attached to the holding body.

The other comprises a cutting unit with a cutting edge which is received in an elongated plastic body and a Holder, with a receiving section for the cutting unit, so that the cutting unit can be exchangeable, being detachable Connecting means for the cutting unit on the one hand and the holding body on the other hand are provided.

In Fig. 7, a known knife 100 of the first type is shown. The knife 100 comprises a holder 101, a holding body with an eccentric attachment part 102 and a receiving opening 103, a cutting part 105 for insertion into the opening 103 and devices 106 for fastening the cutting part

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on the receiving part 104. The eccentric attachment part 102 of the holding body 104 is inserted deep into the opening from the front end of the holder 101 and is then rotatably mounted there. That Cutting part 105 is one cut from a long tendon blade Buckling of broken off piece. The cutting tip 107 is eccentric by the distance L from the axis of rotation 0 of the attachment part 102 arranged. At the other end of the holder 101, an actuating button (not shown) is provided. The button can optionally can be operated to stop the rotation of the eccentric attachment part 102, which allows it to be used as an ordinary knife enables.

In this embodiment, the eccentric attachment part 102 is rotatably connected to the holder 101, but the rotational resistance is so large that the holding body 104 and the cutting part 105 cannot easily be rotated relative to each other. It is even necessary that a fingertip is placed on the holding body and this is moved in this way. Tired of doing it the finger immediately, so that longer work can not be carried out and more complicated cutting work can not possible are. If a new cutting part 105 is inserted, it is also necessary that it is used with it when it is inserted must be handled in the receiving opening 103, the There is a risk of injuring fingers.

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Another known rotary knife is with a small storage between the holding body and the holder to improve the relative Provided rotary movement. This knife has the disadvantage that the mounting of the bearing inside the thin and elongated holder complicates the construction and makes the assembly cumbersome. It is also very expensive.

8 shows a previously known rotary knife of the second type. The rotary knife 200 comprises a holder 201, a receiving body 202 and a cutting unit 203. The holder comprises a shank portion 204 of reduced diameter, the Front end terminated by a hemispherical section 205 will. A peripheral bead 206 is designed as a removable holding part on the circumference of the shaft section 204. the Cutting unit 203 comprises a cutting part 207 and a shaft section 208 made of plastic. In most cases it will the cutting unit 203 is injection-molded in one piece with the shaft section 208. The front part of the shaft section 208 jumps back and thus forms a shoulder 209.

The holding body 202 holds the cutting unit 203 rotatably, the rear end face 210 on the hemisphere 205 of the holder rests. The interior of the holding body 202 is composed of a recess 211 for receiving the shaft body 208 of the

Cutting unit 203 and a further recess 212 for receiving of the shaft portion 204 of the holder 201. The front end of the recess 211 has a reduced cross-section, whereby the shoulder 213 is formed.

The holding body 202 comprises in the interior crossing gaps 214 extending to the rear end, whereby a spring part is formed. The interior of the spring part 215 is provided with an outer recess 216 which the bead 206 of the holder 201 is equivalent to. The cutting unit 203 is inserted through the recess 212 of the holding body 202 and rests on the two Shoulders 209, 213. The holding body 202 is fastened on the holder 201, as shown in FIG.

In the rotary knife 200, the rear face 210 of the cutting unit 203 is in point contact with the hemispherical one Section 205 of the holder 201, the longitudinal movement of the cutting unit 203 being limited by the shoulders 209 and 213 so that the arrangement does not fall apart.

The shaft body 208 of the cutting unit 203 is axially aligned with the holder 201, while the axis of rotation 0 about a certain Distance eccentrically from the cutting edge 217 of the cutting part 207 is.

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With this construction, the cutting unit 203 can by small Forces with respect to the holding body 202 and the holder 201 are twisted because the contact of the rear boundary surface 210 of the cutting unit 203 with the hemispherical portion 205 of the holder 201 is formed point contact-like, so that the Rotational resistance is advantageously very low.

However, the rotary knife 200 is still unsatisfactory in terms of replacing the cutting unit 203. Because every time that If the cutting unit is to be exchanged for a different one, the holding body 202 must be separated from the holder 201. If a pinger is placed on the sliding-off surface of the holding body 202 and moved in the axial direction, so the spring member 215 is thereby compressed, whereby, albeit with difficulty, the engagement of the peripheral bead portion 206 is released into the corresponding recess.

It must therefore be applied considerable forces to cancel the engagement, so that the replacement process tedious and tedious is. In addition, if too great a force is used, there is a risk that the finger that is in contact with the cutting edge 207 will slips and is injured.

US Pat. No. 3,886,656 discloses a rotary knife for overcoming the problem described above. After that there is no holding body, as in the previously described embodiment

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see, but the front section of the holder is provided with a recess for receiving the cutting unit. A Ku- * gel is arranged deep in the recess so that it cannot fall out. This ball is provided to the compressive force of the cutting unit in point contact. Include means for preventing the cutter unit from becoming detached from the holder an annular groove on the shank portion of the cutting unit, a side slot on this recess and a Wire spring carried by the holder in such a way that the free end of the spring part leads into the slot and into the groove the cutting unit comes to rest.

In this known knife, the spring part protrudes from the holder arranged. When handling the knife, it is an obstacle and prevents a good grip. In addition, the spring part is arranged behind the cutting tip, so that the cutting tip during the cutting process can only be observed with difficulty.

Sometimes the cutter unit is accidentally detached from the holder by touching the spring part, resulting in tampering makes it necessary for reattachment.

The inserting or releasing of the cutting unit is done by that the portion facing the cutting tip is held with the fingers, with the risk that the

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Fingers touch the cutting tip so that the handling lacks the necessary safety. The deep introduction of the Ball, which can then not easily be taken out again, makes the construction complicated and expensive.

In view of the problems described above, the object of the invention is to provide a rotary knife that is easier to use Construction and low price an improved rotatability of the cutting unit relative to the holder as well as a improved releasable connection between the same ensured. In addition, it should be ensured with such a rotary knife be that the rotation of the cutting unit relative to the holder and the releasable connection of the two parts is possible, wherein the construction should be such that the cutting body has a recess for receiving a shank portion from the front end the cutting unit, a spring part with several slots and retaining devices with a groove in the recess and a bead on the stem portion.

The knife according to the invention should comprise a shank section of the cutting unit which has a conical section for Having a point contact at the deepest end face of the recess of the body, so as to reduce the resistance to rotation of the cutting unit.

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Furthermore, according to the invention, the rotary knife should be constructed so that the deepest end face of the recess is conically truncated
is hollowed out in order to form an abutment for the conical section of the cutting unit, which also serves to reduce the resistance to rotation of the cutting unit and to ensure the rotation around the conical point.

Another object of the invention is to design a rotary knife so that a pressure ring is provided around the spring part of the body to enable advancement by screw means, the shank portion of the cutter unit being provided with a flange portion to which the pressure ring is detached
the connection of the cutting unit to the body is screwed.

According to the invention it is further provided that the flange section is narrow relative to the thickness of the cutting part, whereby the easy observability of the cutting tip of the cutting part is enabled during the cutting process.

With particular advantage, the invention also provides that the
Safety in handling the flange portion when attaching or detaching the cutting unit to the body is improved.

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Finally, the invention is also characterized in that a corresponding number of cutting units in one Box are arranged, the flange portion serving as a support surface, below which the cutting part in the soft lower part of the box is inserted, with the cutting part standing upright and in this way the insertion of the cutting unit eased into the knife body.

Further features, advantages and details emerge from the following description of a preferred embodiment of FIG Invention and based on the drawing. Show:

1 shows an overall view of the rotary knife according to the invention; FIG. 2 shows a view from the left according to the illustration in FIG. 3; FIG.

Fig. 5 is an enlarged longitudinal section from which the essential Features of the invention can be found;

Fig. 4 shows a cross section along the line IV-IV in Fig. 3;

Fig. 5 is an enlarged section of an inventive S chine idene inhe it;

Fig. 6 is a partial sectional view of a box such as that used in particular is used for a corresponding number of the cutting units according to the invention;

7 shows a partial view of a previously known rotary knife which alone enables the cutting part to be replaced, and FIG

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8 shows a partial sectional view of a previously known rotary knife with exchangeable cutting units, which has a cutting part and having a shaft portion connected thereto.

The rotary knife according to the invention comprises a holder 2, an annular body 3 and a tendon unit 4. The holder 2 consists from an aluminum alloy or the like. and has an elongated, cylindrical shape so that it can be easily grasped. He is provided with a longitudinal recess 5 which extends a certain distance into the interior of the holder 2 from the front end. The holder is also provided with longitudinal slots 6 arranged in a cross shape, which are introduced into a spring part 7. As shown in FIG. 4, the longitudinal slots 6 are arranged in a cross shape in such a way that they form four resilient sections. The number of longitudinal slots and the resilient sections is not limited. The inside of the recess 5 is with a Annular groove 8 for receiving the cutting unit 4 is provided. The rear portion of the spring part 7 is provided with an externally threaded portion 9, the diameter of which is smaller than that of the holder, whereby a Schultex x 10 is formed. A Part of the surface of the holder 2 is to prevent slipping corrugated.

The ring body 3 is on the spring part 7 and on the external thread section 9 of the holder 2 fitted with a gap

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12 towards the spring part 7 and an internal thread section 13 towards the holder 2 is provided. The ring body 3 is from the the same material as the holder 2, namely made of an aluminum compound or the like.

The front half and the outer surface 14 of the ring body 3 is tapered and the other half is fluted with a Section 15 provided to prevent slipping.

The cutting unit k comprises a cutting part 16 made of steel and a shank portion 17 made of synthetic resin. The two parts are joined together during the injection molding of the shaft section 17. The shaft section 17 comprises a flange 18 at the front end and ends with a tapering section 20. The flange can be designed in the form of a disk or, as shown in FIG. 1, shield-shaped. In FIG. 5, the outside diameter of the annular bead 19 is denoted as Dj, that of the shaft section as D2, that of the basic state of the spring part 7 as D3 and the inside diameter of the gap as D4. The space S ^ on one side of the annular bead 19 is (Di - Ü2) / 2 and the space S2 between the space in the basic state and the spring part 7 is (D4 - T> - $) / 2,

The gap S2 is designed to be larger than the gap S ^, so that the spring part 7 is expanded or compressed and can thus be releasably connected to the cutting unit, even if the ring part is mounted on the holder 2.

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of the shaft section 17, and that the diameter of the annular groove 9 is approximately equal to or slightly larger than the outer diameter D> | of Annular bead 19 is.

The pointed section 20 of the cutting unit 4 is supported on a lower surface 21 during the cutting process away. For this reason, there is a gap S3 in the axial direction let in between the groove 8 and the bead 19.

In addition, an intermediate space S4 is provided so that the flange 18 does not contact the front face of the holder 2 and the ring body 3 comes into contact. The maximum outside diameter of the flange 18 is larger than the inside diameter of the recess 5 designed so that the flange 18 can be supported against the ring body 3 when it is by means of the screw device is moved forward. The axis of rotation of the cutting unit 4 is eccentric by a distance L from the cutting edge 22 of the cutting part 16 is arranged.

The handling is so that the cutting unit 4 with the holder 2, as shown in Fig. 1 and 3, connected and for Carrying out the cutting process is gripped on the holder.

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The cutting tip 22 of the cutting part 16 rests on the surface to be cut, not shown, while the holder is handled so that the tip can be guided along the desired cutting directions. The conical section 20 of the cutting unit 4 on the deepest face of the recess 5 from point contact.

The compressive force of the cutting unit 4 is absorbed in the holder 2 in such a way that the shaft section 17 of the cutting unit 4 is rotatably mounted in the recess 5 of the holder 2, so that the cutting unit 4 are not accidentally released can, in that corresponding retaining devices are provided. In this way, the axis of rotation is 0 The cutting unit 4 is eccentric to the cutting tip 22 and the cutting unit 4 can be guided in a curve with a slight force so that complicated lines can be followed.

If the tip 22 becomes blunt, it must be replaced. This is done so that the ring body 3 is relative to the holder is unscrewed by the screw device, the front end of which then rests on the flange 18 of the cutting unit 4 is supported so that the annular bead 19 is excavated from the annular groove 8 by further forward rotation.

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As a result, the spring part 7 is expanded, in which case the flange 18 for removing the cutting unit 4 from the recess 5 of the holder 2 can be gripped. Coins, screwdrivers or other solid, flat pieces can be used as an aid for removing them Objects are used by placing them in the space S4 are inserted between the flange 18 and the ring body 3 so as to the corresponding holding devices 8,19 against the To separate the spring force of the spring part 7, so that the cutting unit 4 can be removed from the recess 5 of the holder 2 can.

Once the retaining bead 19 has been completely removed from the recess 5, the holder 2 is held down and the cutting unit 4 falls out due to gravity so that it is in can be thrown in the trash can. As a result, no finger can come into contact with the cutting part 16.

To insert a new cutting unit 4 into the holder, the shaft section 17 of the cutting unit 4 can be inserted into the recess inserted and pressed deeply in order in this way a coupling between the peripheral bead 19 and the corresponding Bring about recess 8. The coupling is secured by the contraction of the spring part 7, with only the flange portion 18 is handled without a finger coming into contact with the cutting part 16.

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Some cutting units 4 are particularly advantageously in a box 24, as shown in FIG. 6, for fastening one of the same arranged in holder 2.

The box 23 comprises a soft base 24 made of foam or the like. and a transparent cover 25.

The cutting unit 4 is arranged with the cutting part 16 facing downwards in the soft insert 24, the shaft section 17 stands vertically upwards. The flange section 18 of the cutting part 4 is supported against the surface of the soft Insert 24 and thus acts as a seat that ensures the vertical position of the cutting unit 4.

In this way, when the cover 23 is opened, the holder 2 can be made easily accessible and attached to the vertical cutting unit 4 can be added. It is ensured at all times that no finger is in contact with the cutting part 16 comes.

To ensure unhindered movement of the cutting tip 16, It proves to be advantageous that the flange portion 18 of the cutting unit 4 relative to the thickness of the cutting part 16 is narrow.

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Claims (5)

• •• it · ft f «« a ,, if - 17 - Claims for protection 1. Rotary knife with an elongated, handy holder, characterized by an axial recess (5) which is introduced into the holder (2) up to a certain depth from the front end of the holder (2), a receiving surface (21) at the deepest point of the recess (5 ), a spring part (7) with a corresponding number of longitudinal slots (6) at the end facing away from the front of the holder (2), a retaining groove (8) arranged in this recess (5), a cutting unit (4) with a shank section (17), a cutting part (16) and a flange section (18) connected to it, wherein the shaft section (17) can be inserted into the recess (5) and is rotatably mounted there, a retaining groove (19) on the shaft section (17) and a conical section (20) at the rear end of the shaft section (17), the axis of rotation O of the cutting unit (4) being eccentrically removed by a distance L from the cutting tip (22) of the cutting part, the conical section (20) opening up the receiving surface (21) of the holder (2) is supported and the flange section (18) of the cutting unit (4) does not lie against the front end of the holder (2) during the cutting process. - 18 - 2. Rotary knife according to claim 1, characterized in that the holder (2) comprises a tubular annular body (3) with an intermediate space (12), wherein the spring part (7) of the holder (2) is loosely inserted there and an internally threaded portion ( 13) corresponds complementarily to an external thread section (9) of the holder that a gap S _{2 is formed} between the recess (12) of the ring body (3) and the spring part (7) of the holder (2) in order to facilitate the loosening and connection of the cutting unit ( 4) with the holder (2), and that the front end of the ring body (3) cannot be supported during the cutting process on the flange section (18) of the cutting unit (4), but only by unscrewing the ring body. 3. Rotary knife according to claim 1 or 2, characterized in that the holding device in the holder (2) is designed as a peripheral groove (8) and the holding device in the cutting unit (4) is designed as a peripheral bead (19). 4. Rotary knife according to one of claims 1 to 3, characterized in that the receiving surface (21) of the holder (2) has a conical recess such that the angle of inclination is less than that of the conical portion (20) of the cutting unit (4). - 19 - 5. Rotary knife according to one of claims 1 to 4, characterized in that the flange portion (18) of the cutting unit (4) is narrow relative to the thickness of the cutting part (16).