Portable punch press

Abstract

The invention relates to a portable, hand-held punching press (1a; 1b) for manually feeding a workpiece (6) and subsequently punching the workpiece (6), comprising a punching punch (2) and a punching die (4), wherein an open and a closed state can be assumed.Also included is a punch guide element (7) which supports the punch holder (3) along a punch axis (8) so as to be linearly displaceable with respect to a die axis (9), and a first deflection lever (10) with a first arm (11) and a second arm (13), wherein the punch holder (3) is articulated to the first arm (11) of the first deflection lever (10), the second arm (13) is articulated to a first articulated rod (16), the first articulated rod (16) is articulated to a movably mounted spindle nut (18) of a drivable helical gear (19), and wherein a drivable spindle (20) of the helical gear (19) is rotatable about a spindle rotation axis (21) of the helical gear (19) and is arranged so as to be axially immovable with respect to the punch guide element (7).

Description

[0001] The invention relates to a portable, hand-held punch press for manually feeding a workpiece and subsequently punching the workpiece, comprising a punch arranged at one end of a punch holder and a punching die arranged at one end of a die holder. The punch press can be brought into an open state in which the punch is spaced from the punching die and the workpiece can be arranged between the punch and the punching die, and the punch press can be brought into a closed state in which the punch engages the punching die and punches the workpiece.Also included is a punch guide element which is designed to support the punch holder so as to be linearly displaceable along a punch axis with respect to a die axis, a first deflection lever with a first arm having a first arm length and with a second arm having a second arm length which is rotatably mounted about a first pivot point, wherein the punch holder is articulated to the first arm of the first deflection lever.

[0002] Punching with a punch press integrates several manufacturing processes into a single operation within a single movement of the punch or punch die. The term punching, and in the context of the present disclosure, can be understood to mean the following manufacturing processes that can be performed with the punch press. Depending on the design of the punch and punch die, forming, separating, dividing, shear cutting, wedge cutting, tensile forming, deep-cutting, widening, embossing, punching, upsetting, pressure forming, bite cutting, fine blanking, cutting out, trimming, deburring, etc. can be performed. The manufacturing processes mentioned do not constitute an exhaustive list of all feasible manufacturing processes.

[0003] The ability to perform these many different manufacturing processes makes punch presses a particularly versatile tool, often used on construction sites. However, punch presses have not yet made significant inroads into drywall construction.

[0004] In drywall construction, it is common practice for metal profiles in a stud wall, in a single-wall construction, to create openings for electrical cables and installation lines. These openings are usually created before the metal profiles are installed, as subsequent modification of the metal profiles would be geometrically disadvantageous. At the very least, the openings must be created before the opposing sides of the metal profiles are covered with plasterboard or construction boards. Some metal profiles, also known as CW profiles, already have so-called H-cuts, which can be bent open to insert electrical cables and installation lines into the resulting openings.

[0005] If no H-shaped punches are present, most drywall construction projects use a core drill bit, which is commonly used for drilling out holes for sockets or switches. The core drill bit is also used if there are no H-shaped punches at the required height in the metal profile.

[0006] However, creating openings using a core drill bit comes with many disadvantages. For example, access to the metal profiles with a core drill bit is limited because most metal profiles have a U-shaped cross-section. Access is particularly difficult when the opening needs to be created after the metal profiles have already been installed and connected to other metal profiles. It may even be impossible to position a drill with a core drill bit parallel to the drywall against the desired metal profile.

[0007] The same applies to conventional punching presses, which have even more limited access to metal profiles. Most punching presses are designed only for stationary operation, meaning they are not portable, and certainly do not allow the processing of an already installed metal profile.

[0008] Furthermore, conventional punching presses have the disadvantage that they usually operate with a substantially constant force and, consequently, a constant working speed throughout their entire working stroke. However, for U-shaped metal profiles, this is a significant disadvantage, as the high force required for punching is only needed when in contact with the workpiece at a single working point. Moving the punch to the punching die is therefore particularly time-consuming and delays progress on a construction site.

[0009] A punching press according to the prior art is disclosed in EP 1 839 768 A1. The punching press shown is designed as a table press and is therefore not portable. The punching press shown is intended for cutting and finishing flat bar material for window fittings. It includes a manually operated or motor-driven spindle for the lifting drive of one or more punching tools interacting with a die.

[0010] Another related device is known from DE 42 33 233 A1, which discloses a hand-operated lever press.

[0011] Another punching press is known from US 5279197 A, which shows a non-portable punching press with a housing, a die, and a punch. By rotating a spindle, a spindle nut can move up and down along the spindle. The spindle nut is movably connected to a first articulated rod, which in turn is movably connected to a bell crank. Rotation of the spindle thus leads to rotation of the bell crank about a fixed pivot point, causing a hammer to strike the punch, which is then moved towards the die. The hammer is not connected to the punch. This enables embodiments in which multiple punches are provided and either the hammer or the punches are designed to be movable. This means that either the hammer can be moved towards the individual punches, or the individual punches can be positioned one after the other under the hammer.

[0012] In light of the prior art, the object of the invention can be seen as providing a solution to the above-mentioned disadvantages of known punching presses. The primary objective is to provide a punching press that enables faster punching, while being portable during operation and improving the feedability of workpieces. Secondly, the punching press provided is particularly suitable for working on stud walls.

[0013] According to the invention, the present object is achieved in that the second arm of the first deflection lever of the punching press is articulated to a first articulated rod with a first articulated rod length, wherein the first articulated rod is articulated to a movably mounted spindle nut of a drivable helical gear, and wherein a drivable spindle of the helical gear is rotatable about a spindle rotation axis of the helical gear and is arranged axially immovably with respect to the punch guide element.

[0014] The punch press according to the invention offers the advantage that, by providing the aforementioned elements, a variable transmission ratio of force to travel is created. When the punch press is moved from the open to the closed state, the punch initially travels a large distance in a short time. As the punch approaches the punch die, the travel is increasingly slower, with the effective force, or punching force, increasing. Thus, the punching of thin-walled workpieces, which require a large distance between the punch die and the punch in order to be fed to the punch press, can be carried out particularly effectively and quickly on a construction site.

[0015] In addition, the advantage is that by providing the reversing lever with the screw gear, even workpieces that are particularly close together, or metal profiles of a stud wall, can be machined.

[0016] The design of a bell crank, which provides a first power transmission, is not only advantageous for workpiece accessibility. In conjunction with the second power transmission of the helical gear, particularly high forces can be achieved, while the punch press occupies only a small volume. Thus, the punch press according to the invention can be driven manually via a crank or operated by coupling the spindle to a motorized drill or similar device. This results in a particularly versatile and flexible punch press that fully utilizes a toggle lever effect.

[0017] If the helical gear is designed to be self-locking, it also has the advantage that no force is transferred back from the punching press itself to the user. For example, after punching, the elastic deformation of the punching press or the workpiece would otherwise be partially transferred to the user through the spindle once the counterpressure or preload is removed. This effect is mitigated with the self-locking helical gear.

[0018] The punch guide element also provides the advantage of allowing parallel movement of the punching punch to the punching die. This differs from many conventional presses, or punching presses, in which a punching punch and punching die move at an angle to each other, as the punching punch and punching die are pivotally mounted relative to each other. While the angular movement can achieve satisfactory results, in most applications, parallel movement of the punching punch and punching die is preferable. However, parallel movement is difficult to achieve in a compact design and thus in a portable punching press that simultaneously achieves the force-transmission ratio according to the invention.

[0019] In one embodiment, the punch press may further comprise: a die guide element configured to support the die holder along the die axis so as to be linearly displaceable with respect to the punch axis; a second deflection lever having a first arm with a first arm length and a second arm with a second arm length, which is mounted rotatably about a second pivot point; wherein the die holder is articulated to the first arm of the second deflection lever, wherein the second arm of the second deflection lever is articulated to a second articulated rod with a second articulated rod length, and wherein the second articulated rod is articulated to the movably mounted spindle nut of the drivable helical gear.

[0020] This provides the advantage of essentially canceling out the forces around the spindle's rotational axis, making the helical gear less massive and improving the portability of the punch press. Furthermore, the advantage of improved power transmission with a faster travel distance is enhanced, as the punching die is also movably mounted.

[0021] In a further embodiment, the spindle rotation axis of the helical gear can be arranged at right angles to the first punch axis and / or to the die axis. This provides the advantage that the cancellation of forces around the spindle rotation axis is particularly pronounced.

[0022] Preferably, the first arm length of the first bell crank is at most half the length of the second arm length of the first bell crank, and preferably, the first arm length of the second bell crank is also at most half the length of the second arm length of the second bell crank. This provides the advantage of achieving a particularly favorable power transmission ratio.

[0023] In one embodiment, the first joint rod length can be at least a quarter of the second arm length of the first bell crank, and preferably the second joint rod length can also be at least a quarter of the second arm length of the second bell crank. This allows for a particularly favorable power transmission ratio, particularly when the aforementioned ratio of the first arm length to the second arm length is also maintained.

[0024] In a further embodiment, the travel path of the spindle nut on the spindle can be limited such that the first joint rod with the second arm of the first bell crank does not assume a dead center position, and preferably the travel path is limited such that the second joint rod with the second arm of the second bell crank also does not assume a dead center position. This provides the advantage that the spindle nut, the joint rod, and the bell crank cannot jam.

[0025] Preferably, a housing is included, wherein a housing body of the housing is made from at least one bent sheet metal part and / or wherein a cover of the housing is plate-shaped. This provides the advantage that the punching press is particularly inexpensive to manufacture. Furthermore, the risk of injury to a user of the punching press is particularly reduced, since only the area around the punching punch and punching die represents a source of danger. The housing also allows the punching press to be gripped at any desired location, thereby improving ergonomics during use.

[0026] Preferably, the housing is designed such that the envelope of all positions and intermediate positions in the open and closed states essentially occupies the entire housing, without leaving any significant empty spaces in the interior of the housing. This provides the advantage of a particularly compact, portable floor press. The housing can also provide additional containment or guidance for the installed elements.

[0027] In one embodiment, a handle can be arranged near a working point of the punch and die. This provides the advantage that the working point of the punch and die can be moved to the workpiece in a particularly fatigue-free, controlled, and precise manner.

[0028] Advantageous and non-limiting embodiments of the invention are explained in more detail below with reference to the figures. Fig. 1 shows a first embodiment of a portable punching press, comprising a movably mounted punching punch and a stationary punching die. Fig. 2 shows a second embodiment of a portable punching press comprising a movably mounted punching punch and a movably mounted punching die. Fig. 3a shows an open state of the portable punch press according to Fig. 2 . Fig. 3b shows a state between the open state of the Fig. 3a and a closed state of the Fig. 3c . Fig. 3c shows the closed state of the portable punching press according to Fig. 2 . Fig. 4a shows a sectional view of the portable punching press according to Fig. 2 . Fig. 4b shows another sectional view of the portable punching press according to Fig. 2 . Fig. 4c shows a further sectional view of the portable punching press according to Fig. 2 . Fig. 5a shows a cover of the punching press according to Fig. 2 . Fig. 5b shows another sectional view of the punching press according to Fig. 2 . Fig. 6 shows another state of the portable punching press according to Fig. 2 , where the drop can be seen.

[0029] Fig. 1 shows a first embodiment of a portable punch press 1a in a sectional front view, comprising a punch 2 arranged at one end of a punch holder 3 and a punch die 4 arranged immovably at one end of a die holder 5. It can also be seen that the punch press 1a can be brought into an open state, in which the punch 2 is spaced from the punch die 4 and a workpiece 6 can be arranged between the punch 2 and the punch die 4. The punch press 1a can also be brought into a closed state, in which the punch 2 engages the punch die 4 and punches the workpiece 6.

[0030] Furthermore, a punch guide element 7 is included, which is designed to mount the punch holder 3 so as to be linearly displaceable along a punch axis 8 with respect to a die axis 9. A first deflection lever 10 has a first arm 11 with a first arm length 12 and a second arm 13 with a second arm length 14 and is rotatably mounted about a first pivot point 15. Furthermore, the punch holder 3 is articulated to the first arm 11 of the first deflection lever 10, wherein the second arm 13 of the first deflection lever 10 is articulated to a first articulated rod 16 with a first articulated rod length 17. The first joint rod 16 is articulated to a movably mounted spindle nut 18 of a drivable helical gear 19, wherein a drivable spindle 20 of the helical gear 19 is rotatable about a spindle rotation axis 21 of the helical gear 19 and is arranged axially immovable with respect to the punch guide element 7.

[0031] Fig. 2 shows a second embodiment of a portable punching press 1b in an uncut isometric view with the cover removed. With regard to the punching press 1a, the punching press 1b further comprises a movably mounted punching punch 2 and a movably mounted punching die 4. The punching press 1b further comprises a die guide element MF, which is designed to support the die holder 5 so as to be linearly displaceable along the die axis 9 with respect to the punch axis 8. A second deflection lever 22 has a first arm 23 with a first arm length 24 and a second arm 25 with a second arm length 26, wherein the second deflection lever 22 is rotatably mounted about a second pivot point 27. The die holder 5 is articulated to the first arm 23 of the second reversing lever 22, wherein the second arm 25 of the second reversing lever 22 is articulated to a second articulated rod 28 with a second articulated rod length 29.Furthermore, the second joint rod 28 is connected in an articulated manner to the movably mounted spindle nut 18 of the drivable screw gear 19.

[0032] Due to these mechanical conditions, a movement mechanism for the punching punch 2 of the punching press 1a, mirrored about the spindle rotation axis 21, is also designed for the punching die 4, so that the punching die 4 is also movably mounted. Furthermore, a housing 31 is adapted accordingly so that the mirrored movement mechanism is also enclosed by the housing 31.

[0033] The following explanations concern punching press 1b and are to be extended accordingly to punching press 1a. Punching press 1a differs from punching press 1b only in that only the punching punch 2 comprises a movement mechanism. In the following, the movement mechanism can be understood as the combination of those elements that are connected to one another in an articulated manner.

[0034] The terms punch 2 and punch die 4 are essentially interchangeable. This means that, independently of all the above-mentioned Figuren 1 bis Fig. 5a Either the circular, cup-shaped punch 2 can have a larger or smaller circumference than the punching die 4. The punch 2 or the punching die 4 could also be plate-shaped. These can also be designed in such a way that a wide variety of opening shapes can be produced. For example, it may be expedient to form essentially rectangular or oval openings in metal profiles. This also represents a further advantage over the core drills mentioned above, which are limited to forming circular openings. The punch 2 and the punching die 4 can also be designed in such a way that several separate openings are formed in a single punching process.

[0035] In the Fig. 1 bis Fig. 4b It can be seen that the punch 2 is detachably connected to the punch holder 3 via a nut M. The same applies to the punching die 4, which is connected to the die holder 5 via a nut M.

[0036] From the Fig. 2 It can be seen that the die holder 4 and the punch holder 3 have a wrench surface S at the opposite end, to which a wrench can be attached so that the nuts M can be tightened more easily.

[0037] It should also be noted that the die holder 5 and the punching die 4 can be monolithic, or one-piece. The same applies to the punching punch 2 and punch holder 4.

[0038] The punch holder 3 and die holder 4 can be cylindrical, although any other cross-sectional shape is also possible. The punch guide element 7, as shown, can provide a sliding guide for the punch holder 3. However, all other linear guide designs are also conceivable. The same applies to the die guide element MF and the die holder 5.

[0039] The workpiece 6 shown in the Fig. 1 bis Fig. 5a is a U-shaped metal profile of a stud wall of a drywall construction, which is arranged between the punching punch 2 and the punching die 4. During punching, a circular opening is made in the metal profile. However, the punching presses 1a, 1b described herein are not limited to punching metal profiles. Any conventional workpiece 6 that can generally be processed with a punch or press can also be processed with the punching press 1a, 1b according to the invention.

[0040] It should also be mentioned that in the Fig. 1 , and Fig 3a bis Fig. 3c the workpiece 6 has already been punched as a metal profile. The resulting waste AB, or punching slug, is thus represented as remaining in the punching die 4. Since the waste AB is pressed into a cambered shape by the nut M in the punching die 4 in the embodiment shown, it can be assumed that the outer diameter of the waste AB is reduced and that it would therefore not remain clamped in the punching die 4, but would fall out on its own if the punching press 1a, 1b were tilted. However, it would in any case be conceivable to integrate, for example, a spring-loaded ejector into the punching press 1a, 1b, which automatically ejects the waste AB after the punching press 1a, 1b is opened.

[0041] It should also be noted here that the term "articulated" means that the elements can pivot relative to each other about a respective joint axis. However, the articulated elements can also be connected via ball joints, hinge joints, etc.

[0042] The spindle rotation axis 21 of the screw gear 19 is arranged in all figures at right angles to the first punch axis 8, or to the die axis 9. The spindle rotation axis 21 is arranged essentially in the same plane as the rest of the punch press 1a, 1b. The plane of the rest of the punch press 1a, 1b is understood to mean that the main extension extends only in two directions that span a plane. A height of the punch press 1a, 1b, as in Fig. 2 shown, is relatively small compared to a main length dimension and a main width dimension. However, the spindle rotation axis 21 and thus also the helical gear 19 can be arranged at any angle to the punch axis 8, whereby in the punching press 1b, a non-uniform feed of the punch 2 can be achieved compared to the punching die 4. The arrangement of the spindle axis 21 can also deviate from the plane of the main extension, whereby improved accessibility to workpieces 6 can be achieved in special applications.

[0043] The punching presses 1a and 1b can be operated manually via the spindle 20. For this purpose, the spindle 20 can be rotated via a connectable hand crank on a spindle connection element SA, which is designed, for example, as a hexagon, in order to move the punching presses 1a and 1b into the open or closed state. A drill can also be attached to the spindle connection element SA. The punching presses 1a and 1b can also have their own internal motorization for driving the spindle 20. Internal motorization can be understood as an electric motor that is flanged to the spindle 20. The internal motorization can also be designed such that the spindle 20 can still be driven manually.

[0044] An additional gear can also be connected between the spindle connection element SA and any type of drive to achieve a modified power transmission ratio. The additional gear, or an angle gear, can also redirect a shaft input direction at an angle, allowing previously inaccessible workpieces 6 to be reached with the punching presses 1a and 1b.

[0045] The spindle nut 18 can be designed so that it can be disengaged from the spindle 20. For example, this can be achieved using a divisible spindle nut 18. This provides the advantage that the open and closed states can be quickly adopted without driving the spindle 20. This can be supported by a spring preload so that after driving and punching, the spindle nut 18 disengages and returns to the open state as quickly as possible, thus enabling particularly rapid processing. This is particularly useful because low forces are usually required to transition from the closed state to the open state.

[0046] The following conditions of the movement mechanism have proven particularly advantageous. It is advantageous if the first arm length 12 of the first bell crank 10 is at most half the length of the second arm length 14 of the first bell crank 10, and the first arm length 24 of the second bell crank 22 is at most half the length of the second arm length 26 of the second bell crank 22.

[0047] In addition, it is advantageous if the first joint rod length 17 is at least a quarter of the second arm length 14 of the first bell crank 10, and wherein the second joint rod length 29 is also at least a quarter of the second arm length 26 of the second bell crank 22.

[0048] The term "portable" can be understood to mean that the total weight of the punching presses 1a and 1b is such that they can be manually fed to workpieces 6, with the punching press 1a, 1b being held in the hands of a user. A handle 34 can also be provided, which enables a particularly ergonomic positioning of the punching press 1a, 1b. Additional handles can also be provided on the punching presses 1a and 1b. Likewise, fastening points for straps (not shown) can be provided, so that part of the total weight of the punching presses 1a and 1b can be transferred over a user's shoulder. Thus, the total weight does not have to be supported exclusively by the user's hands.

[0049] Fig. 3a shows an open state of the portable punch press 1b from Fig. 2 . In this Fig. 3a the first arm length 24 of the first arm 23 and the second arm length 26 of the second arm 25 of the second bell crank 22 are shown to improve the clarity of the remaining figures. In addition, Fig. 3a the maximum travel distance 30 is shown. Fig. 3b shows a state between the open state of the Fig. 3a and closed state of the Fig. 3c and the Fig. 3c shows a fully closed state of the punching press 1b of the Fig. 3b .

[0050] The open state is characterized by the punching punch 2 and the punching die 4 being spaced apart from each other to the maximum extent, so that workpieces 6 are located between, or on, the punch axis 8 and the die axis 9. In addition, the longitudinal axis of the joint rods 16, 28 is substantially parallel to the spindle rotation axis 21 if the spindle rotation axis 21 is perpendicular to the punch axis 8. When the spindle 20 is driven, the spindle nut 18 is moved toward or away from the spindle connection element SA along the movable path 30. The longitudinal axis of the joint rods 16, 28 forms an angle β with respect to the spindle rotation axis 21, wherein the angle β in Fig. 3b und Fig. 3c is evident. In Fig. 3c the angle β is essentially 100° in order to make the most of a toggle lever effect.

[0051] At this point it should be mentioned that the first and second joint rods 16, 28 are understood to be a rod-like element which has holes at its ends for bolts B which are connected in an articulated manner to the spindle nut 18 and to the bell crank 10, 22.

[0052] A working point 35 of the punching presses 1a and 1b can be located at the intersection point of the spindle rotation axis 21 and the punch axis 8. However, the working point 35 can also be located next to the spindle rotation axis 21, as can be seen from the Fig. 1 It is particularly expedient if the handle 34 is also arranged along the spindle rotation axis 21 in the vicinity of, or in the area of, the working point 35, since this results in punching presses 1a and 1b with which the working point 35, at which punching takes place, can be assigned to a workpiece 6 in a particularly intuitive manner.

[0053] In summary, the Fig. 3a bis Fig. 3c It can be seen that the movable path 30 of the spindle nut 18 on the spindle 20 is limited in such a way that the first articulated rod 16 with the second arm 13 of the first reversing lever 10 does not assume a dead center position, and wherein the movable path 30 is preferably limited in such a way that the second articulated rod 28 with the second arm 25 of the second reversing lever 22 does not assume a dead center position. The movable path 30 is understood to mean the entire distance that the spindle nut 18 can travel on the spindle 20. The movable path 30 can be limited by the housing 31, by the punch guide element 7 or the die guide element MF, or by the bearing blocks L of the spindle 20.It should be mentioned that the first articulated connection from the spindle nut 18 to the first and second articulated rods 16, 28 can act beyond a dead center, i.e. slightly overextended - as shown - in order to fully utilize a toggle lever effect for the closed state of the punching press 1a, 1b shortly before an overextension.

[0054] The dead center position of the movement mechanism or lever mechanism means that the articulated elements and their force vectors lie on a common straight line.

[0055] Bearing block L of the spindle 20 is understood to be an element that rotatably supports the spindle 20 and prevents displacement in an axial direction of the spindle 20. In all figures, one end of the spindle 20 is received in a rolling bearing, and the other end is guided in a sliding guide provided in a bore in the housing body 32.

[0056] In addition, the Fig. 3a bis Fig. 3c It is apparent that the housing 31 is designed in such a way that the envelope of all positions and intermediate positions in the open state and in the closed state essentially occupies the entire housing 31, without leaving any significant empty spaces in the interior of the housing 31.

[0057] The term “envelope of all positions” is thus understood to mean that the housing 31 is dimensioned just large enough for the movement mechanism to essentially completely occupy the housing 31 in the open state, in the closed state, and in all positions in between.

[0058] Fig. 4a shows a front view of a sectional view of the punching press 1b of the Fig. 2 analogous to the view of the Fig. 1 of the punching press 1a. The same analogous sectional view is also shown in the Fig. 3a bis Fig. 3c reproduced. Fig. 4a also shows that the first and second bell cranks 10, 22 are characterized by a deflection angle α. This deflection angle α is essentially 45° in all figures.

[0059] However, the term "reversing lever 10, 22" can also be understood to mean that the deflection angle α between the first and second arms 11, 13, 23, 25 of the respective reversing lever 10, 22 is essentially 0° to 135°. The first and second pivot points 15, 27 can also be located after the first and second arms 11, 13, 23, 25. Thus, the reversing lever 10, 22 can be designed as a one-sided or two-sided lever. In the figures, the reversing lever 10, 22 is always a two-sided lever.

[0060] In the Fig. 1 and Fig. 3a until Fig. 4a It can be seen that the punch holder 3 and the die holder 5 are pivotally connected to the first arm 11, 23. This connection can be implemented—as shown—via bolt B and a corresponding bore in the punch holder 3 and die holder 5. The bore can be circularly adapted to the bolt B if the punch holder 3 with the punch guide element 7 is toleranced in such a way that the movement of the first deflection lever 10 is possible without jamming. The same applies to the die holder 5 with the die guide element MF and the second deflection lever 22.

[0061] As shown, the bore is designed as an elongated hole to prevent jamming in another way, while maintaining the advantage that the punch holder 3 and die holder 5 can be guided more precisely by the punch guide element 7 and die guide element MF.

[0062] Fig. 4b shows a further sectional view of the punching press 1b according to Fig. 2 and the Fig. 4c also shows a further sectional view of the punching press 1b according to Fig. 2 . From the Fig. 4b und Fig. 4c shows how the punching presses 1a and 1b are constructed in a sectioned side view. It can be seen that the first deflection lever 10 and the second deflection lever 22 are designed as two spaced-apart plates, with a sleeve inserted around the pivot point 15, 27. The punch holder 3 and the die holder 5 are arranged between the deflection levers 10, 22. It can also be seen that the bolts B each act as a joint in double shear. This design allows particularly large forces to be transmitted through the movement mechanism.

[0063] Fig. 5a shows a front view of the punching press 1b of the Fig. 2 , wherein a cover 33 closes the housing body 32 of the housing 31 so that the movement mechanism cannot be reached by a user, in order to minimize the risk of injury. The housing body 32 can be manufactured largely as a bent sheet metal part or from several screwed bent sheet metal parts, wherein the punch guide element 7, the die guide element MF, and at least one of the spindle bearing blocks L can be designed as a milled element with a greater wall thickness so that several screw connections SV can hold the punching press 1a, 1b together. The cover 33 can also be detachably screwed to the housing body 32 in order to allow easy access to the housing 31. The cover 33 is designed as a plate-shaped, flat element. The housing body 32 can also consist of a plate-shaped base plate that is similar to the cover 33.The remainder of the housing body 32 can consist of three screwed U-shaped profiles as shown.

[0064] Fig. 5b shows a further sectional view of the punching press 1b according to Fig. 2 . However, the punching press 1b is in its closed state, and not as in the Fig. 2 shown in an intermediate position. This figure shows that the handle 34 can be made of two different materials. For example, the handle can be made of metal, with the gripping surface being provided from a rubberized plastic to improve grip.

[0065] For a particularly portable punching press 1a, 1b, the following dimensions have proven to be useful: first arm length 12 of the first bell crank 10 and first arm length 24 of the second bell crank 22 = 51 mm; second arm length 14 of the first bell crank 10 and second arm length 26 of the second bell crank 22 = 100 mm; first joint rod length 17 and second joint rod length 29 = 50 mm; travel distance 30 = 90 mm; pitch of the spindle 20 and spindle nut 18 = M16×1.5 mm; weight of the punching press: less than 10 kilograms, as low as possible; distance A in the open state = 55 mm; distance A in the closed state essentially = 0 mm.

[0066] It should be mentioned that, for example, the spindle 20 and the spindle nut 18 can be replaced by a spindle 20 and spindle nut 18 with a larger or smaller pitch in order to accelerate the working speed or increase the achievable force if a construction site requires the processing of increasingly thin or thick workpieces 6. The dimensions of the kinematics according to the illustrated embodiment were developed empirically. Since a large number of parameters are involved here (center distance of the lever pivot point (210 mm), 2x lever length of the reversing lever (51 mm & 100 mm), length of the coupling rod (50 mm), width of the spindle nut (55 mm) and stroke of the spindle nut (0-90 mm)), the entire system must always be considered when defining alternative embodiments with possible alternative lengths in order for it to function.

[0067] Finally, it should be mentioned that in connection with the Fig. 4a the section line CC stands, where the Fig. 4c the corresponding section view CC shows. The section line AA of the

[0068] Fig. 4b will be in Fig. 3a bis Fig. 4a shown. The section line BB of the Fig. 5a will be in Fig. 4b shown. And the section line DD of the Fig. 5a will be in Fig. 5b Following the ISO standard for the placement of views, the Fig. 5a a front view, where the Fig. 4b right next to the Fig. 5a would be arranged in a technical drawing, the Fig. 4a right next to the Fig. 4b , the Fig. 4c right next to the Fig. 4a , and the Fig. 5b under the Fig. 5a .

[0069] Fig. 6 shows another state between the state of Fig. 3b and the closed state of the Fig. 3c the portable punch press 1b. In contrast to the Fig. 3a bis 3c is in the Fig. 6 the waste AB can be recognized. For the rest, please refer to the description of the Fig. 3a bis 3c referred to.

Claims

1. A portable, hand-held punching press (1a; 1b) for manually feeding a workpiece (6) and subsequently punching the workpiece (6), comprising: - a punching punch (2) arranged at one end of a punching punch holder (3); - a punching die (4) arranged at one end of a die holder (5); which can be brought into an open state in which the punching punch (2) is spaced from the punching die (4) and the workpiece (6) can be arranged between the punching punch (2) and the punching die (4), and which can assume a closed state in which the punching punch (2) engages the punching die (4) and punches the workpiece (6); - a punch guide element (7) which is designed to support the punch holder (3) so as to be linearly displaceable along a punch axis (8) with respect to a die axis (9);- a first deflection lever (10) with a first arm (11) with a first arm length (12) and a second arm (13) with a second arm length (14), which is rotatably mounted about a first pivot point (15), wherein the punch holder (3) is articulated to the first arm (11) of the first deflection lever (10); characterized in that the second arm (13) of the first reversing lever (10) is articulated to a first articulated rod (16) having a first articulated rod length (17), wherein the first articulated rod (16) is articulated to a movably mounted spindle nut (18) of a drivable helical gear (19), and wherein a drivable spindle (20) of the helical gear (19) is rotatable about a spindle rotation axis (21) of the helical gear (19) and is arranged axially immovably with respect to the punch guide element (7).

2. Punching press (1a; 1b) according to claim 1, further comprising: a die guide element (MF) designed to support the die holder (5) along the die axis (9) so as to be linearly displaceable with respect to the punch axis (8); a second deflection lever (22) having a first arm (23) with a first arm length (24) and a second arm (25) with a second arm length (26), which is rotatably mounted about a second pivot point (27); wherein the die holder (5) is articulated to the first arm (23) of the second reversing lever (22), wherein the second arm (25) of the second reversing lever (22) is articulated to a second articulated rod (28) with a second articulated rod length (29), and wherein the second articulated rod (28) is articulated to the movably mounted spindle nut (18) of the drivable helical gear (19).

3. Punching press (1a; 1b) according to one of claims 1 or 2, characterized in thatthe spindle rotation axis (21) of the screw gear (19) is arranged at right angles to the first punch axis (8) and / or to the die axis (9).

4. Punching press (1a; 1b) according to one of claims 1 to 3, characterized in that the first arm length (12) of the first reversing lever (10) is at most half as long as the second arm length (14) of the first reversing lever (10), and wherein preferably the first arm length (24) of the second reversing lever (22) is at most half as long as the second arm length (26) of the second reversing lever (22).

5. Punching press (1a; 1b) according to one of claims 1 to 4, characterized in that the first joint rod length (17) is at least a quarter of the second arm length (14) of the first reversing lever (10), and wherein preferably the second joint rod length (29) is also at least a quarter of the second arm length (26) of the second reversing lever (22).

6. Punching press (1a; 1b) according to one of claims 1 to 5, characterized in thata movable path (30) of the spindle nut (18) on the spindle (20) is limited such that the first joint rod (16) with the second arm (13) of the first reversing lever (10) does not assume a dead center position, and wherein preferably the movable path (30) is limited such that the second joint rod (28) with the second arm (25) of the second reversing lever (22) does not assume a dead center position.

7. Punching press (1a; 1b) according to one of claims 1 to 6, characterized in that a housing (31) is included, wherein a housing body (32) of the housing (31) is made of at least one bent sheet metal part and / or wherein a cover (33) of the housing (31) is plate-shaped.

8. Punching press (1a; 1b) according to one of claims 1 to 7, characterized in thatthe housing (31) is designed in such a way that an envelope of all positions and intermediate positions in the open state and in the closed state essentially occupies the entire housing (31) without leaving any significant empty spaces in the interior of the housing (31).

9. Punching press (1a; 1b) according to one of claims 1 to 8, characterized in that a handle (34) is arranged near a working point (35) of the punch (2) and the punch die (4).

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