MANUALLY OPERATED PRESS

Abstract

A manually operated press comprising an actuating member coupled to a shaft, wherein an actuation of the actuating member is converted into a stroke movement of a press ram coupled to the shaft, and hence also into a change in a relative position of the press ram. The press furthermore comprises a reset mechanism for resetting the actuating member, which reset mechanism counteracts the actuation of the actuating member and causes a return movement of the press ram opposite the stroke movement. The reset mechanism comprises a spiral spring.

Claims

1. A manually operated press, comprising: a shaft; an actuating member coupled to the shaft; a press ram coupled to the shaft; and a reset mechanism that is configured to reset the actuating member; wherein an actuation of the actuating member is converted into a stroke movement of the press ram; wherein the reset mechanism is configured to counteract the actuation of the actuating member and to cause a return movement of the press ram opposite the stroke movement, and wherein the reset mechanism comprises a spiral spring.

2. The manually operated press as claimed in claim 1, wherein the spiral spring comprises a spirally wound leaf spring.

3. The manually operated press as claimed in claim 1, further comprising: a slider housing; and a spring housing mounted in the slider housing; wherein the shaft is arranged to be rotatable in the slider housing, and the press ram is longitudinally guided in the slider housing, and wherein the spiral spring is arranged in the spring housing.

4. The manually operated press as claimed in claim 3, wherein the spring housing comprises a pot-like or basket-like housing part and a cover part attached to the housing part.

5. The manually operated press as claimed in claim 3, wherein a radially inner end of the spiral spring is attached to the shaft, and a radially outer end of the spiral spring is attached to the spring housing.

6. The manually operated press as claimed in claim 5, wherein the spiral spring comprises a first connecting link at the radially inner end and a second connecting link at the radially outer end.

7. The manually operated press as claimed in claim 6, wherein each of the first connecting link and the second connecting link comprises a curved portion that is integrally connected to the spiral spring, wherein the curved portion of the first connecting link is curved in a direction of curvature of the spiral spring, and wherein the curved portion of the second connecting link is curved opposite to the direction of curvature of the spiral spring.

8. The manually operated press as claimed in claim 7, wherein the shaft comprises a web that is oriented parallel to a longitudinal axis of the shaft, wherein a cavity is arranged between the web and an outer side of the shaft facing towards the web, and wherein the first connecting link engages in the cavity.

9. The manually operated press as claimed in claim 8, wherein the shaft comprises a flat face on the outer side facing towards the web.

10. The manually operated press as claimed in claim 9, wherein a top side of the web facing away from the shaft is flush with an outer circumferential face of the shaft.

11. The manually operated press as claimed in claim 1, wherein the actuating member comprises an actuating lever that is coupled to the shaft and runs transversely to the shaft, wherein a counterweight is arranged on a side of the shaft opposite the actuating lever and is coupled to at least one of the actuating lever and the shaft, and serves as a torque balance during actuation of the actuating lever, wherein the counterweight has a greater mass than the actuating lever, and a center of gravity of the counterweight has a shorter distance from the shaft than a center of gravity of the actuating lever.

12. The manually operated press as claimed in claim 11, wherein the actuating member furthermore comprises a handle lever that is mounted on the actuating lever transversely to the actuating lever, and wherein a mass of the counterweight is dimensioned such that during actuation of the actuating lever, the counterweight serves as a torque balance for the actuating lever and the handle lever.

13. The manually operated press as claimed in claim 12, wherein the handle lever is mounted on the actuating lever so as to be rotatable about a longitudinal axis of the handle lever.

14. The manually operated press as claimed in claim 12, wherein the counterweight comprises a first counterweight and a second counterweight, wherein a mass of the first counterweight is dimensioned such that during actuation of the actuating lever, the first counterweight serves as a torque balance for the actuating lever, and wherein a mass of the second counterweight is dimensioned such that during actuation of the actuating lever, the second counterweight serves as a torque balance for the handle lever.

15. The manually operated press as claimed in claim 14, wherein the first and second counterweights are each releasably coupled to at least one of the actuating lever and the shaft, and wherein the handle lever is mounted releasably on the actuating lever.

16. The manually operated press as claimed in claim 1, wherein the shaft comprises a spur gear shaft, and the press ram or a component coupled to the press ram comprises a toothing in which the spur gear shaft engages.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0055] FIG. 1 a first perspective view of a manually operated press according to a first embodiment;

[0056] FIG. 2 a second perspective view of the manually operated press according to the first embodiment;

[0057] FIG. 3 a side view of the manually operated press according to the first embodiment;

[0058] FIG. 4 a front view of the manually operated press according to the first embodiment, wherein parts of the manually operated press are depicted in an exploded illustration;

[0059] FIG. 5 a top view of a spiral spring according to an embodiment;

[0060] FIG. 6 a perspective view of a spring housing according to an embodiment;

[0061] FIG. 7 the spring housing shown in FIG. 6 together with the spiral spring shown in FIG. 5, in an exploded illustration;

[0062] FIG. 8 a top view of an embodiment of a shaft used in the press;

[0063] FIG. 9 a sectional view of the shaft shown in FIG. 8;

[0064] FIG. 10 a perspective view of a second embodiment of the press; and

[0065] FIG. 11 a side view of the press shown in FIG. 10 according to the second embodiment.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0066] FIGS. 1 to 4 show a first embodiment of a manually operated press. The press as a whole is designated with the reference sign 10.

[0067] The press 10 comprises a base part 12 which is typically known as a press frame. The press frame 12 forms the basic structure of the press 10 and substantially serves as a carrier for the other components of the press 10. The press frame 12 is usually placed on a support, for example a workbench.

[0068] A so-called slider 14 is mounted on the press frame 12, and in the present embodiment is arranged on the press frame 12 so as to be adjustable in the height direction indicated by the double arrow 16. This adjustability allows the slider 14 to be adjusted in the height direction 16 according to the workpiece size and desired stroke.

[0069] At the side of the slider 14, an actuating member 18 is arranged which, in the present embodiment, is configured as a linear actuating lever 20. This actuating member 18 serves for manual actuation of the press 10. Instead of an actuating lever 20, in principle a wheel or other type of handle may be used to actuate the press 10 by hand.

[0070] In the present embodiment, the press 10 is configured as a rack press. A press ram 24 is guided longitudinally in the housing of the slider 14, known as the slider housing 22. A shaft 26, shown in detail in FIGS. 8 and 9, is arranged transversely, preferably orthogonally thereto in the slider housing 22.

[0071] The shaft 26 is mounted rotatably in the slider housing 22. In the present embodiment, the shaft is configured as a spur gear shaft (see FIGS. 8 and 9). The spur gear shaft 26 may either be formed as one piece, wherein the spur gear 28 is integrally connected to the shaft 26, or may be formed from multiple pieces, wherein the spur gear 28 is inserted in a corresponding shaft-hub connection on the shaft 26.

[0072] The shaft 26 is coupled to the press ram 24. More precisely, the spur gear 28 engages in a toothing 30 provided on the rear side of the press ram 24 (see FIG. 3).

[0073] The actuating member 18 or actuating lever 20 is coupled to the press ram 24 via the shaft 26 that is mounted rotatably in the slider housing 22. An actuation of the actuating lever 20 in the direction of the arrow 32 (shown schematically in FIG. 3) leads to a stroke movement of the press ram 24, in which the press ram 24 is moved downward in the direction of the arrow 34 (see FIG. 3). A shaft 36 running parallel to the press ram 24, and also guided longitudinally in the slider housing 22, prevents a twist of the press ram 24 during this stroke movement. The shaft 36 is therefore described as an anti-twist device.

[0074] When the press 10 is configured as a rack press, the toothing 30 need not necessarily be arranged on the press ram 24 itself. In principle, it could also be arranged on the shaft or anti-twist device 36.

[0075] At the lower end of the press ram 24, a tool receiver 38 is provided for receiving customer-specific pressing tools. Different pressing tools can be attached to this tool receiver 38 relatively easily using a fixing means, for example by means of a screw. The ram stroke is determined by the length of the toothing 30 arranged on the press 24 and the adjustment angle of the actuating lever 20.

[0076] For easier operation, the press 10 furthermore comprises a reset mechanism 40, which is shown at least in part in FIGS. 4 to 7. This reset mechanism serves for resetting the press ram 24 and hence also the actuating lever 20. The reset mechanism 40 causes a return movement of the press ram 24 or actuating lever 20 which is opposite to the stroke movement of the press ram 24 or actuating movement of the actuating lever 20. This return movement moves the press ram 24 upward in the direction of the arrow 42 (indicated schematically in FIG. 3) and moves the actuating lever 20 back to its starting position in the direction of the arrow 44 (indicated schematically in FIG. 3). This starting position, in which the press ram 24 is at its upper stop, is shown in FIG. 3.

[0077] The force of the reset mechanism 40 is produced by a spiral spring 46, which is shown in detail in FIG. 5. The spiral spring 46 comprises a strip-like spring leaf 48 or spring plate wound in a spiral pattern. In contrast to a helical spring or torsion spring, such a spiral spring 46 is under tension when loaded. Loading tightens or winds the spirally wound spring leaf 48. This shortens the distance between the radially outer windings and the radially inner windings of the spring leaf 48. Such a spiral spring 46 is also known as a motive spring.

[0078] The spiral spring 46 is arranged on the shaft 26 or around the shaft 26. The radially inner end 50 of the spring leaf 48 is preferably connected directly to the shaft 26. On rotation of the shaft 26 during the stroke movement, which corresponds to a counterclockwise rotation of the shaft 26 in FIGS. 3 and 5, the spring leaf 48 tightens as stated above and winds onto the shaft 26.

[0079] An inner housing wall may be provided at the radially inner end of the spiral spring 46, in order to prevent a direct contact of the radially inner windings of the spring leaf 48 with the shaft 26. This is however only an optional possibility and not the case in the embodiment shown in FIG. 5.

[0080] An essential advantage of the use of such a spiral spring 46 is that the reset force, even with several revolutions of the shaft 26, only increases slightly in comparison with the helical spring or torsion spring. As a result, for the operator there is only a minimal force difference between the starting position and the maximum position of the actuating lever 20. The return movement takes place very similarly.

[0081] A further advantage of such a spiral spring 46 is that, in contrast to a helical spring or torsion spring, this does not expand under load, so it can be accommodated very compactly in the slider housing 22.

[0082] In comparison with a helical spring or torsion spring, the spiral spring 46 furthermore guarantees the possibility of generating a relatively large reset force despite comparatively fewer windings.

[0083] The spiral spring 46 is preferably arranged in an extra housing 52, known as the spring housing. Accommodating the spiral spring 46 in such a spring housing 52 offers the advantage that the spiral spring 46 can be preloaded in advance, i.e. before its installation in the slider housing 22, and then inserted together with the spring housing 52 in the slider housing 22. This is advantageous in particular from safety aspects since there is no risk to the installation engineer from the spiral spring 46. Also, installation of the spiral spring 46 is thereby considerably simplified.

[0084] The spring housing 52 shown in FIGS. 6 and 7 has a two-part structure. The spring housing 52 comprises a pot-like or basket-like housing part 54 and a cover part 56 which can be connected, preferably releasably, to the housing part 54. In the embodiment shown here, the mechanical connection of the pot-like or basket-like housing part 54 and cover part 56 takes place by caulking of several metal tabs 58. In principle however, various other types of connection of the two parts 54, 56 of the spring housing 52 are conceivable, e.g. with screws, a bayonet closure etc.

[0085] In order to minimize friction in the dynamic state, the spiral spring 46 is preferably coated with a lubricant before installation in the spring housing 52.

[0086] At its radially inner end, the spiral spring 46 comprises a first connecting link 60 for attaching to the shaft 26. At its radially outer end 62, the spiral spring 46 comprises a second connecting link 64 for attaching to the spring housing 52. The two tabs 60, 64 are preferably integrally connected to the spring leaf 48 of the spiral spring 46. Particularly preferably, the two tabs are configured as curved portions which are created by bending the ends 50, 62. Both tabs 60, 64 are curved preferably more strongly than the spring leaf 48 or other parts of the spring leaf 48 of the spiral spring 46. The first connecting link 60 is curved in the direction of curvature of the spiral spring 46. The second connecting link 64 is curved opposite to the curvature of the spiral spring 46.

[0087] By means of said tabs 60, 64, the spiral spring 46 can be attached relatively easily by fixing to the shaft 26 or spring housing 52. As a counterpiece to the first connecting link 60, a web 66 is provided on the shaft 26 (see FIGS. 8 and 9). This web 66 runs parallel to the longitudinal axis 68 of the shaft 26. Below the web 66 is a cavity 70 in which the first connecting link 60 of the spiral spring 46 engages. The cavity 70 lies at an outside of the shaft which faces towards the web 66 and is set back relative to the outer periphery of the shaft 26. On this outside, the shaft 26 preferably comprises a flat face 72. This flat face 72 or the cavity formed between the flat face 72 and the web 66 simplifies insertion of the first connecting link 60 of the spiral spring 46.

[0088] As evident from FIG. 9, the top side 74 of the web 66 facing away from the shaft 26 is arranged flushed with an outer circumferential face 76 of the shaft 26. This has the advantage that when the spiral spring 46 is wound up, no folds are formed within the spring leaf 48 since the spring leaf 48 can wrap itself evenly around the circumference of the shaft 26. This effectively avoids premature breakage of the spiral spring 46, so the service life of the spiral spring may be extended multiple times.

[0089] The second connecting link 64 arranged at the radially outer end 62 of the spiral spring 46 is attached to a web 78 of the spring housing 52 (see FIG. 6). This type of connection between the spiral spring 46 and the shaft 26 or spring housing 52 by means of tabs 60, 64 has the particular advantage that, firstly, mounting is relatively simple, and secondly, the spiral spring or spring leaf 48 is not weakened by the tabs 60, 64.

[0090] It is understood that the advantages resulting from the tabs 60, 64 would also be achieved if the spiral spring 46 were attached directly to the slider housing 22 (without the spring housing 52). Such an arrangement would also be conceivable using a corresponding web on the slider housing 52 (similar to the web 78 on the spring housing 52).

[0091] In the present embodiment, after installation in the spring housing 52 and in the already preloaded state, the spiral spring 46 is inserted in a recess provided in the slider housing 22 and then mounted by means of the cover 80, which is attached to the slider housing 22 for example by means of two screws 82 (see FIG. 4).

[0092] In the next step, the shaft 26 need merely perform a revolution in order to attach the first connecting link 60 of the spiral spring 46 on the web 66 or in the cavity 70. This takes place more or less automatically by rotation of the shaft 26. Further movement of the actuating lever 20 in the actuation direction 32 causes the inner exposed windings of the spiral spring 46 to bear on the shaft 26 or on the windings already wound onto the shaft 26.

[0093] The advantage here is that the installation dimension of the spiral spring 46, which is predefined by the spring housing 52, does not change. Only the ratio of outer windings to inner windings of the spring leaf 48 changes. As soon as the spiral spring 46 is mounted in the slider housing 22 and connected to the shaft 26 in the manner described above, the starting position of the press ram 24 and actuating lever 20 can then be adjusted relative to one another, in order to set the desired starting position of the actuating lever 20. For this, the actuating lever 20 is attached, preferably releasably, to the shaft 26 so that it can be adjusted accordingly in the direction of the arrow 32 or in the direction of the arrow 44 during setup of the press 10, and then re-attached to the shaft 26.

[0094] FIGS. 10 and 11 show a second embodiment of the press. The press as a whole is designated with the reference sign 10. For all other components which correspond to the components of the press 10 according to the first embodiment, the same reference signs as before are used. Also, only the differences between the second embodiment, shown in FIGS. 10 and 11, and the first embodiment, shown in FIGS. 1 to 4, are explained below. The other statements relating to the spiral spring 46, spring housing 52 and shaft 26 also apply accordingly to the second embodiment.

[0095] As well as a comparatively larger ram stroke, the press 10 according to the second embodiment substantially differs in the design of the actuating member 18.

[0096] The actuating member 18 comprises an actuating lever 20 and a handle lever 84, which is mounted on the actuating lever 20 transversely to the actuating lever 20. Such a handle lever 84 is frequently described as an ergo handle. The handle lever 84 is advantageous in particular in pressing processes with a long ram stroke, since here the actuating lever 20 must perform a rotational movement of >360. On such a large rotational movement, the handle lever 84 prevents an awkward repositioning on the actuating lever 20 which is disadvantageous both ergonomically and for safety reasons, since the user's hand can relatively easily slip off the actuating lever 20 during such a repositioning.

[0097] In order to further improve the ergonomics, the handle lever 84 may be mounted on the actuating lever 20 so as to be rotatable about its longitudinal axis. In this way, the user may very easily exert force on the handle lever 84 or actuating lever 20 without needing to change the orientation of his hand during actuation.

[0098] Nonetheless, the handle lever 84 is an optional feature since, in principle, the press may be operated without the handle lever 84, purely by means of the actuating lever 20. The handle lever 84 is therefore preferably mounted releasably on the actuating lever 20 so that the handle lever 84 may be used or omitted as desired.

[0099] Furthermore, a counterweight 86 is mounted on the actuating member 18. This counterweight 86 serves to compensate for the own weight of the actuating lever 20 and the handle lever 84 where used. The counterweight 86 provides a torque balance which allows the actuating member 18 to be moved continuously, irrespective of its angular position. This allows a more pleasant operation for a user of the press, without the force or moment conditions changing during actuation of the actuating member 18. Also, because of the counterweight 86, the return movement of the actuating member 18 is continuous.

[0100] Because of the provision of the counterweight 86, the reset mechanism 40 may also be made smaller. This in turn results in a less powerful acceleration of the actuating member 18 by the reset mechanism 40 during the return movement. A risk potential for the user of the press may thereby be substantially minimized.

[0101] Because of its very compact arrangement, the counterweight 86 also scarcely constitutes any hindrance to the user. Preferably, it has a larger mass than the actuating lever 20. If the actuating lever 20 is used together with the handle lever 84, the mass of the counterweight 86 is dimensioned larger than the sum of the masses of the actuating lever 20 and handle lever 84. For this reason, the counterweight 86 may be designed relatively small. The center of gravity of the counterweight 86 has a shorter distance from the shaft 26 than the center of gravity of the actuating lever 20 or handle lever 84.

[0102] The counterweight 86 may be mounted on the shaft 26 and/or the actuating lever 20.

[0103] In the embodiment shown here, the counterweight 86 has a first counterweight 88 and a second counterweight 90. The first counterweight 88 serves as a weight or torque balance for the actuating lever 20. The second counterweight 90 serves as a weight or torque balance for the handle lever 84.

[0104] The two counterweights 88, 90 are preferably coupled releasably to the actuating lever 20 and/or the shaft 26. If the press is operated solely with the actuating lever 20, only the first counterweight 88 is used and the second counterweight 90 is removed from the press. If however the actuating lever 20 is used together with the handle lever 84, both counterweights 88, 90 are used. Thus a linear reset force of the reset mechanism 40 may be produced, irrespective of whether the actuating lever 20 is used with or without the handle lever 84.

[0105] It is to be understood that the foregoing is a description of one or more preferred exemplary embodiments of the invention. The invention is not limited to the particular embodiment(s) disclosed herein, but rather is defined solely by the claims below. Furthermore, the statements contained in the foregoing description relate to particular embodiments and are not to be construed as limitations on the scope of the invention or on the definition of terms used in the claims, except where a term or phrase is expressly defined above. Various other embodiments and various changes and modifications to the disclosed embodiment(s) will become apparent to those skilled in the art. All such other embodiments, changes, and modifications are intended to come within the scope of the appended claims.

[0106] As used in this specification and claims, the terms for example, e.g., for instance, such as, and like, and the verbs comprising, having, including, and their other verb forms, when used in conjunction with a listing of one or more components or other items, are each to be construed as open-ended, meaning that the listing is not to be considered as excluding other, additional components or items. Other terms are to be construed using their broadest reasonable meaning unless they are used in a context that requires a different interpretation.