EP0258723B1 - Perforator for letters - Google Patents

Abstract

1. Letter perforator, comprising a bottom section (1), forming a base plate (11) and lateral walls (12), and a pressure plate (2), which is hinged onto the lateral walls (12) and acts on two punch dies (4) which are under the influence of a spring (5), in which respect the punch-die guides are formed by at least one separate single member (3; 6), which is connectable to the bottom section (1) and substantially S-shaped with three bent areas (31, 32, 33; 61, 62, 63), positioned in parallel planes, the uppermost and middle bent area (31, 32; 61, 62) including recesses, which constitute the punch-die guides, the middle bent area (32; 62) of which upwardly defines an insertion slot, and the lowermost bent area (33; 63) downwardly defines the insertion slot, forming the template, characterised in that the middle and lowermost bent area (32, 33; 62, 63) are directly connected to one another by a web (36), which defines the insertion slot in the rearward direction and serves as a stop for the paper to be perforated, that the uppermost bent area (31; 61) of the single member (3; 6) has at least one tongue (35; 65), which protrudes from the narrow side of the uppermost bent area and engages into a recess (16) of the lateral wall (12), and that the single member (3; 6) is rigidly anchored in the region of its lowermost bent area (33; 63).

Description

The invention relates to a letter punch with a lower part forming a base plate and side cheeks and a pressure plate articulated on the side cheeks and acting on two punch punches under the action of a spring, the punch punch guides being connected by at least one separate, essentially S- Shaped shape with three individual parts lying in parallel planes are formed, the top and middle bends of which form the punch guide recesses, the middle bend delimits an insertion slot at the top and the bottom bend delimits the insertion slot at the bottom and forms the die.

A letter punch of this type is already known (GB-A 581 433), in which the S-shaped individual part containing the punch guide consists of three sheet metal strips rigidly connected to one another by a fastening screw on the lower part, and in the middle one as a spacer The end of the sheet metal strip inserted between the upper and lower strips serves as a stop for the paper to be punched. The known letter punch is not suitable for perforating thick stacks of paper, since the height of the insertion slot is determined by the thickness of the sheet used and is therefore quite small. In addition, the manufacture or assembly of the individual part is labor-intensive, since the metal strips must be individually shaped, connected to one another and provided with a threaded hole for the fastening screw before they can be screwed onto the lower part of the punch from below.

Furthermore, it is known per se in a letter punch with a wooden lower part and two metal strips embedded in the lower part, which serve as punch guide guides (FR-A 955 676), to design the metal strips as individual parts which can be connected to the lower part and which each have three bends lying in parallel planes , whereby the middle and lowest bend are directly connected to each other by a web. In order to be able to fix the metal strips to the lower part in the correct position, the lower part must be provided with cutouts there, which make its manufacture more difficult. The metal strips can also not be pushed directly onto the lower part, but must be bent up slightly so that the top bend can be pushed over the front edge of the lower part. In addition, the metal strips in the known letter punch are not bent in an S-shape, but have a further bend for the mounting of the pressure lever axis.

Proceeding from this, the object of the invention is to improve the letter punch of the type specified at the outset in such a way that its individual parts are easier to produce and can be assembled automatically.

To achieve this object, the combinations of features specified in claims 1 and 7 are proposed. Further advantageous refinements and developments of the inventive concept result from the dependent claims.

The two solution variants according to the invention have in common that the middle and lowermost bend of the individual part containing the punching guides and the die are directly connected to one another by a backward-delimiting slot which serves as a stop for the web to be punched, so that the individual part is connected by a relative simple bending process can be brought into the S shape.

In the case of the first variant of the solution, the assembly of the letter punch is facilitated in that the uppermost bend of the individual part has at least one tongue which projects beyond the narrow side of the uppermost bend and engages in a recess in the side cheek, while the individual part can be positively anchored in the region of its lowest bend on the lower part is. For this purpose, the lowermost bend advantageously has at least one anchoring tongue directed downwards and engaging in a corresponding slot in the base plate. A further improvement in this respect is achieved in that the lowermost bend, which delimits the insertion slot, has an obliquely downward-pointing extension which bears against a corresponding incline of the lower part.

As an alternative to the first solution variant, the middle and lowermost bends and the web of the individual part connecting them, which delimits the depth of the insertion slot, have widenings projecting on both sides over the top bend and the web connecting the top and middle bends, while in the side walls parallel to Insertion slot aligned, open edge slot cutouts are arranged for the precise fit of the widenings.

A preferred embodiment of the second solution variant provides that support ribs pointing to the inside of the hole to form vertical support for the lateral edge region of the uppermost bend are formed on the side cheeks. To produce a snap connection between the individual part and the lower part, the bottom bend expediently has a preferably obliquely downward extension, the lateral edge edges of which have a locking rib or locking shoulder engaging in a locking recess in the side cheeks. The lowermost bend and at least part of its extension can rest on the lower boundary edges of the slot recesses arranged in the side cheeks and, in the further course of the extension, rest with their side edges against the inner surfaces of the side cheeks following the locking ribs.

• Fig. 1 Die Brieflocherteile eines ersten Ausführungsbeispiels in perspektivischer Explosionsdarstellung;
• Fig. 2 das Unterteil und zwei mit je einem Lochstempel bestückte Einzelteile eines zweiten Ausführungsbeispiels in perspektivischer Explosionsdarstellung;
• Fig. 3 das Unterteil und ein mit zwei Lochstempeln bestücktes Einzelteil eines dritten Ausführungsbeispiels in perspektivischer Explosionsdarstellung und in zusammengebautem Zustand.

The invention is explained in more detail below on the basis of the exemplary embodiments shown schematically in the drawing. Show it:

• Figure 1 shows the letter punch parts of a first embodiment in a perspective exploded view.
• 2 shows the lower part and two individual parts of a second exemplary embodiment, each equipped with a punch, in a perspective exploded illustration;
• Fig. 3 shows the lower part and an individual part equipped with two punches of a third embodiment in a perspective exploded view and in the assembled state.

The lower part of the letter punch formed from a sheet metal blank has a base plate 11 and two side cheeks 12 which are bent vertically upwards. Bearing eyes 13 for storing the pressure plate 2 are recessed in the side cheeks 12. In the case of FIGS. 1 and 2, there are further provided cutouts 16 on the upper edges of the two side cheeks 12 which, together with slots 15 recessed in the base plate 11, serve to fix the insertable individual part 3 forming the punch guide. In the base plate 11 there are also two circular recesses 14 which have a slightly larger diameter than the punch 4.

The pressure plate 2 has lateral bends 21 which overlap the side cheeks 12 of the lower part 1 and from which inwardly pointing sleeve-shaped pins 22 are pressed out, by means of which the pressure plate 2 is mounted on the lower part 1. Pressure bodies 23 acting on the end faces of the punch 4 are welded to the underside of the pressure plate 2. These pressure bodies can also be formed in that tongues cut out of the pressure plate 2 are bent downwards, which have a downward curvature and are supported with their free end on the underside of the pressure plate 2.

The individual part 3 or 3 'which forms the punch guides and the insertion slot has three bends 31, 32, 33 lying parallel to one another, in the top bends 31, 32 of which the punch 4 are guided. The lowermost bend 33 forms the die and has a front, obliquely downward extension 34. The punch 4 are encompassed by a helical spring 5, one abutment of which is formed by the bend 32 and the other abutment is formed by an annular disk clamped in an annular groove of the punch 4.

In the exemplary embodiment according to FIG. 1, tongues 35 which protrude beyond the side edges of the bend 31 and which engage in the open-edge recesses 16 of the side cheeks 12 as well as anchoring tongues 37, from which the two lower bends 32 and 33 connecting web 36 are cut out and bent downward and engage in the slots 15 of the base plate 11.

2, the punch guides are formed by two separate individual parts 6, which in addition to the three parallel bends 61, 62, 63 also have two bends 66 pointing forward. The bends 61 and 62 serve to guide the punch 4, while the bottom bend 63 serves as a die. The lowermost bend 63 also has an extension 64 which is bent on the front and which engages in an open slot 17 of the base plate 11 for anchoring the individual part 6. For further fixation of the individual part 6, recessed open slots 67 are used in the bent parts 66, the flanks of which bear against a rod 7, which is mounted in the side cheeks 12 of the lower part 1 and serves as a pivot axis for the pressure plate 2. In this exemplary embodiment too, a tongue 65 projecting beyond the outer edge thereof is provided on the uppermost bend 61 and engages in the open-edge recess 16 of the side cheek 12 in question.

In the exemplary embodiment shown in FIG. 3, the individual part 3 ′ is equipped, similarly to the case in FIG. 1, with two punching guides arranged at a distance from one another. The lowermost bend 33 and the middle bend 32 and the web 36 connecting the individual part 3 'connecting them have widenings projecting on both sides beyond the uppermost bend 31 and the web 40 connecting the uppermost and the middle bend, while in the side cheeks 12 parallel for the insertion slot aligned, open edge slot recesses 17 'are arranged for precisely fitting the widenings 39. The lowermost bend 33 has a forwardly directed, obliquely downward extension 41, 34, the lateral edge of which contains a locking rib or locking shoulder 38 engaging in a locking recess 18 in the side walls. The lowermost bend 33 and at least part of the extension 41 lie on the lower boundary edges of the slot cutouts 17. In the further course of the extension 41, 34 following the locking ribs 38, it lies with its side edges against the inner surface of the side cheeks 12 and in this way delimits a forwardly closed chamber for receiving punched-out pieces of paper. In the upper region of the side cheeks 12, support ribs 19 are formed in the form of a bend or shape for vertical support of the uppermost bend 31.

Claims (9)

1. Letter perforator, comprising a bottom section (1), forming a base plate (11) and lateral walls (12), and a pressure plate (2), which is hinged onto the lateral walls (12) and acts on two punch dies (4) which are under the influence of a spring (5), in which respect the punch-die guides are formed by at least one separate single member (3; 6), which is connectable to the bottom section (1) and substantially S-shaped with three bent areas (31, 32, 33;'61, 62, 63), positioned in parallel planes, the uppermost and middle bent area (31, 32; 61, 62) including recesses, which constitute the punch-die guides, the middle bent area (32; 62) of which upwardly defines an insertion slot, and the lowermost bent area (33; 63) downwardly defines the insertion slot, forming the template, characterised in that the middle and lowermost bent area (32, 33; 62, 63) are directly connected to one another by a web (36), which defines the insertion slot in the rearward direction and serves as a stop for the paper to be perforated, that the uppermost bent area (31; 61) of the single member (3; 6) has at least one tongue (35; 65), which protrudes from the narrow side of the uppermost bent area and engages into a recess (16) of the lateral wall (12), and that the single member (3; 6) is rigidly anchored in the region of its lowermost bent area (33; 63).

2. Letter perforator according to claim 1, characterised in that the single member (3; 6) has, in the region of the lowermost bent area, at least one downward pointing anchoring tongue (37; 64), which engages into a corresponding slot (15; 17') of the base plate (11).

3. Letter perforator according to claim 1 or 2, characterised in that at least one 180_° offset bent anchoring tongue (37) is cut out of web (36) of the single member (3), which web connects the two lowermost bent area (32, 33) and defines the depth of the insertion slot.

4. Letter perforator according to one of the claims 1 to 3, characterised in that the lowermost bent area (33), which defines the insertion slot, comprises a transversely downward pointing extension (34) which abuts against a corresponding transver- sity of the bottom section.

5. Letter perforator according to one of the claims 1 to 4, characterised in that two punch dies (4), arranged at a distance from one another, are mounted to the single member (3).

6. Letter perforator including a bottom section (1'), forming a base plate (11) and lateral walls (12) and a pressure plate, which is hinged onto the lateral walls (12) and acts on two punch dies (4), which are under the influence of a spring (5), in which respect the punch-die guides are formed by at least one separate single member (3'), which is connectable to the bottom section (1') and substantially S-shaped with three bent areas (31, 32, 33), positioned in parallel planes, the uppermost and middle bent area (31, 32) includes recesses, which constitute the punch-die guides, the middle bent area (32) of which upwardly defines an insertion slot, and the lowermost bent area (33) downwardly defines the insertion slot, forming the template, characterised in that the middle and lowermost bent area (32, 33) are directly connected to one another by a web (36), which defines the insertion slot to the rear and serves as a stop for the paper to be perforated, and that they comprise protrusions extending on both sides over the uppermost bent area (31) and the web (40) which connects the uppermost and the middle bent area (32), and that open-edge slot recesses (17) for spatially precise reception of protrusions (39) are arranged in the lateral walls (12).

7. Letter perforator according to claim 6, characterised in that support ribs (19), facing towards the inside of the perforator, for vertical support of the lateral edge region of the uppermost bent area (31), are formed onto the lateral walls (12).

8. Letter perforator according to claim 6 or 7, characterised in that the lowermost bent area (33) includes a preferably transversely downward pointing extension (41, 34), the lateral edges comprising a positioning rib or positioning shoulder (38) which engages in a positioning recess (18) of the Lateral walls (12).

9. Letter perforator according to claim 8, characterised in that the lowermost bent area (33) and at least one part (41) of its extension abuts against the lower defining edges of the slot recesses (17) arranged in the lateral walls (12), and along the course (34) of the extension adjacent to the positioning ribs (38) abuts with its lateral walls against the inner surfaces of the lateral walls (12).

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