HYDRAULICALLY ACTUATABLE WORK DEVICE DESIGNED TO BE HANDHELD

Abstract

A hydraulically activatable working device includes a hydraulic cylinder and at least one first and one second partial piston provided therein. The partial pistons can be moved under pressurization by a hydraulic medium to perform a working operation. Each partial piston has an impact surface at its lower end against which the hydraulic medium may act. A piston rod is coupled to the hydraulic cylinder and has an impact surface at its lower end against which the partial pistons may act. The impact surface forms a first partial impact surface against which the first partial piston acts, and forms a second partial impact surface against which the second partial piston acts. The first and second partial impact surfaces do not overlap each other in direction across to the traversing direction.

Claims

1. A hydraulically activatable working device designed for performing a working operation, comprising: a hydraulic cylinder and at least one first and one second partial piston provided for in the hydraulic cylinder, wherein the partial pistons can be moved under pressurization by a hydraulic medium in a traversing direction in the hydraulic cylinder for performing the working operation, wherein each partial piston has an impact surface at its lower end against which the hydraulic medium may act, wherein the partial pistons are acted on over the whole working operation at its impact surfaces with the respectively same hydraulic pressure, wherein further a piston rod is provided which is coupled to the hydraulic cylinder, wherein the piston rod at its lower end has an impact surface against which the partial pistons may act, wherein further the piston rod is provided for separately to the partial pistons and can only be acted on by one partial piston or by several or all partial pistons at the same time, wherein further within the hydraulic cylinder a return spring is provided for, wherein the partial pistons are moveable in the traversing direction within the hydraulic cylinder under the pressure of the hydraulic medium against the force of the return spring, wherein further a tool is provided for, which is coupled to the piston rod and moveable therewith and wherein the partial pistons are provided for acting on the same working part, wherein the impact surface forms a first partial impact surface against which the first partial piston is provided for to act, and forms a second partial impact surface against which the second partial piston is provided for to act, and wherein the first and second partial impact surfaces do not overlap each other in direction across to the traversing direction.

2. The working device according to claim 1, wherein all partial impact surfaces are located inside of the hydraulic cylinder over the entire operation.

3. The working device according to claim 1, wherein a first partial piston has a first impact surface, and each additional partial piston has an additional impact surface.

4. The working device according to claim 3, wherein the second and possible further impact surface is provided for within the first impact surface of the first partial piston.

5. The working device according to claim 3, wherein the first and the in the given case second and in the given case additional impact surfaces of the partial pistons do have in the traversing direction opposite to each other a first and in the given case second and in the given case further transfer surfaces opposite to the respective impact surface, and that the first and in the given case second and further transfer surface is provided for to transfer power from the first, in the given case second and further partial impact surfaces to the piston rod.

6. The working device according to claim 1, wherein the return spring acting on a partial piston is only extending within the hydraulic cylinder.

7. The working device according to claim 1, wherein the partial pistons reset are resettable by the return spring.

8. The working device claim 1, wherein the return spring is acting directly only between the hydraulic cylinder and the piston rod.

9. The working device according claim 1, wherein the piston rod does have an impact flange for the return spring.

10. The working device according to claim 9, wherein the impact flange of the piston rod is provided for within a sleeve part of the first partial piston.

11. The working device according to claim 1, wherein only one return spring is provided.

12. The working device according to claim 1, wherein a first gasket seals the first partial piston against an inner surface of the hydraulic cylinder and that a second gasket seals the partial piston against an outer surface of a further partial piston.

13. The working device according to claim 1, wherein each partial piston has geometrical middle axis extending in the traversing direction, wherein the geometrical middle axes do coincide or that several partial pistons are guided telescopically within each other.

14. The working device according to claim 13, wherein the geometrical middle axes of partial pistons are distant to each other.

15. The working device according to claim 1, wherein several further partial pistons are arranged in a through opening of the first partial piston which is assigned to only one of these further partial pistons.

16. The working device according to claim 1, wherein a further partial piston is arranged eccentrically to in view of the first partial piston concerning it impact surface.

17. The working device according to claim 1, wherein a surface midpoint of an additional impact surface is arranged offset to a surface midpoint of the first impact surface.

18. The working device according to claim 1, wherein the impact surfaces are designed so as not to overlap in direction across to the traversing direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The invention will be explained in more detail below based on exemplary embodiments. Shown on:

[0053] FIG. 1 is a cross section through a hydraulic cylinder and a working head of a working device with partially depicted hull device, in an initial position, with two partial pistons arranged concentrically to each other;

[0054] FIG. 2 is an illustration according to FIG. 1 after applying hydraulic pressure and moving the first partial body into a stop position;

[0055] FIG. 3 is an illustration according to FIG. 1 or FIG. 2, after further moving the second partial piston as compared to FIG. 2;

[0056] FIG. 4 is a schematic illustration of a working device as a whole;

[0057] FIG. 5 is a cross section according to FIG. 1, given an arrangement with three partial pistons, at the beginning of an operation;

[0058] FIG. 6 is the arrangement according to FIG. 5 at the end of an operation;

[0059] FIG. 7 is a cross section according to FIG. 1, in an arrangement with two pairs of identical partial pistons, arranged eccentrically in relation to a central azis;

[0060] FIG. 8 is a cross section through the arrangement according to FIG. 7, cut along line VIII-VIII on FIG. 7; and

[0061] FIG. 9 is the arrangement according to FIG. 7 at the end of an operation.

DESCRIPTION OF THE EMBODIMENTS

[0062] Shown and described is a hydraulically activatable working device 1 designed as a hand tool. With reference to FIG. 4, the working device preferably has an accumulator 2, an electric motor 3, advantageously a gearbox 4 and a pump 5. The pump 5 can be used to pump hydraulic fluid into a hydraulic cylinder 6. The hydraulic fluid can run back into a storage space 7, and from there be pumped back into the hydraulic cylinder 6 again during an additional operation.

[0063] Given a preferably rodlike arrangement as depicted on FIG. 4, a gripping area can be provided that envelops the motor 3 and/or the gearbox 4 and/or the pump 5.

[0064] An activating switch 8 can further be provided.

[0065] As evident with further reference to FIGS. 1 to 3, a first partial piston 9 and a second partial piston 10 are arranged in the hydraulic cylinder 6 in a first embodiment. The second partial piston 10 is arranged inside of the first partial piston 9.

[0066] Further provided is a piston rod 11, which can be acted upon by the partial pistons 9, 10.

[0067] The piston rod 11 acts upon a tool 13 movably guided in a working head 12. In the exemplary embodiment, the tool 13 is preferably detachably connected with the piston rod 11.

[0068] In the exemplary embodiment, a movably guided first tool 13 and a second tool 14 are preferably fizedly arranged in the working head 12.

[0069] The exemplary embodiment involves a crimping device, preferably for crimping wire end ferrules. A crimping opening 15 is here left between the tools 13 and 14, which is diminished as the piston rod 11 increasingly travels, see FIGS. 2 and 3 proceeding from FIG. 1.

[0070] The two partial pistons, the first partial piston 9 and the second partial piston 10 each have a first impact surface 16 for acting upon the first partial piston 9 with hydraulic fluid, and a second impact surface 17 for acting upon the second partial piston 10 with hydraulic fluid. During the course of an operation, these impact surfaces 16 and 17 can be acted upon by the hydraulic means (not shown in detail) that are pumped into the hydraulic cylinder 6 for performing an operation.

[0071] The two partial pistons, the first partial piston 9 and the second partial piston 10 act upon the same tool 13 by way of the piston rod 11.

[0072] During the performance of an operation of the kind depicted on FIGS. 2 and 3 proceeding from FIG. 1, the hydraulic fluid acts upon the first partial piston 9 and the second partial piston 10 with the same respective hydraulic pressure over the entire operation. This correspondingly happens even if the second partial piston 10 is not moved any further as the result of having reached a stop.

[0073] The piston rod 11 has an overall impact surface 18, by way of which both partial pistons 9, 10 can act upon the piston rod 11.

[0074] As evident from a comparison of the state on FIG. 3 to FIG. 2, the overall impact surface 18 of the piston rod 11 can be acted upon only by the second partial piston 10 while performing an operation; it is then detached from the first partial piston 9 and located a distance above it. The here annular partial impact surface located a distance away from the first partial piston is supplemented by the additional, here circular partial impact surface, which is acted upon by the second partial piston, to form the overall impact surface. On their part, the partial pistons 9, 10 each have a first or a second transfer surface 19, 20, with which they can act upon the respective partial impact surface of the overall impact surface 18 of the piston rod 11.

[0075] As shown in the exemplary embodiment, the overall impact surface 18 of the piston rod 11 is preferably formed as a uniformly flat surface, which also extends essentially perpendicular to a traversing direction V of the piston rod 11 during an operation. Nonetheless, only a partial area of the impact surface 18 is always acted upon by the transfer surface 19 or 20 of the first or second partial piston 9, 10.

[0076] The first partial piston 9 is further preferably designed with a stop part. In the exemplary embodiment and as further preferred, the stop part is designed as a sleeve part 23. The sleeve part 28 can be integrally designed with the first partial piston 9. However, it can also be designed separately from the first partial piston 9, or integrally with the working head 12.

[0077] During the movement of the first partial piston 9, see the position on FIGS. 2 and 3, the sleeve part 28 obviously arrives at a stop 21, which is formed in the working head 12. Nevertheless, the first partial piston 9 can then not proceed any farther at a further elevated hydraulic pressure.

[0078] As preferred in this exemplary embodiment, but also further preferred in all exemplary embodiments, only a single return spring 22 is provided. The return spring 22 acts between the working head 12 and the piston rod 11. The return spring 22 preferably acts upon an impact flange 23 of the piston rod 11. Even opposite a side upon which the return spring 22 acts, the impact flange 23 preferably forms a part of the impact surface 18 for the first or second partial pistons 9, 10. As further preferred, both in this exemplary embodiment and further in all exemplary embodiments, the return spring 22 is arranged in an annular space between the sleeve part 28 and an outer surface of the piston rod 11.

[0079] The return spring 22 is further supported at the top against a cylinder cover 45.

[0080] The working head 12 is preferably formed so as to include a part of the hydraulic cylinder, here the cylinder cover 45 and a partial cylinder wall 47 that extends from the cylinder cover 45 in the direction toward a cylinder floor 46. The inside of the partial cylinder wall 47 can comprise part of the threaded connection 26.

[0081] The first partial piston 9 further preferably has a first gasket 24, with which it is sealed against an inner surface of the hydraulic cylinder 6. The first partial piston 9 further preferably has a second gasket 25, with which it forms a seal relative to the second partial piston 10.

[0082] The working head 12 is further preferably designed so that it can be detached from the hydraulic cylinder 6. In this exemplary embodiment and preferably in all exemplary embodiments, a threaded connection 26 is provided between the working head 12 and the hydraulic cylinder 6. A locking screw 27 can be used to fix the working head 12 in a screwed on position of the kind corresponding to FIGS. 1 to 3.

[0083] The impact flange 23 of the piston rod 11 further preferably moves inside of the sleeve part 23. An outer surface thereof here preferably borders an inner surface of the sleeve part 28.

[0084] The second partial piston 10 has a stop flange 30, with which it comes to a stop against an allocated stop 34 of the first partial piston when in the extended position, see FIG. 3. Since in the exemplary embodiment the gasket is obviously arranged after the stop 34 only in the traversing direction V, the stop 34 or related surface in this respect must still include the hydraulic impact surface of the first partial piston 9, and the stop flange 30 in this respect is no effective hydraulic part of the impact surface of the second partial piston 10.

[0085] In the embodiment on FIGS. 5 and 6, a third partial piston 29 is provided in addition to the first partial piston 9 and the second partial piston 10, proceeding from the embodiment on FIGS. 1 to 3. All three partial pistons have coinciding geometric central axes A.

[0086] The second partial piston 10 is here designed as a sleeve part, which preferably guides the third partial piston 29 on its inner surface, and is guided in the first partial piston 9 on its outer surface. The first 9 and the second partial piston 10 correspondingly have an annular impact surface, while the third partial piston 29 has a circular impact surface.

[0087] All three partial pistons 9, 10, 29 telescope into each other. The third partial piston 29 is designed as a cylindrical partial piston with a stop flange 30 corresponding to the stop flange 30 of the second partial piston 10 in the first embodiment. As also the case in the first embodiment, the stop flange 32 together with the central area of the third partial piston 29 further forms a shared circular surface on the bottom side, which if hydraulically effective is an impact surface 31.

[0088] In a comparable manner, the second partial. piston 10 of this embodiment has a flange 30, which on the bottom side correspondingly adjoins the circular impact surface 33.

[0089] In the extended position at the end of an operation as shown on FIG. 6, just the third partial piston 29 acts upon a partial impact surface of the overall impact surface 18 of the piston rod 11 corresponding to its transfer surface 20′. The second partial piston 10 and/or the third partial piston 29 can each abut a stop 34 or 35 of the first piston 9 or the second piston 10.

[0090] Otherwise, the description of the first embodiment also applies, unless any specifics were addressed here.

[0091] The additional embodiment according to FIGS. 7 to 9 has second partial pistons 36 and third partial pistons 37 (see FIG. 3), which in the exemplary embodiment and preferably are formed in pairs. The second partial pistons 36 and third partial pistons 37 here each preferably have a matching length 1 or 1′ in relation to the traversing direction V. The second partial pistons 36 or the third partial pistons 37 are each accommodated in a bore-like receiving opening 38, 39, 40, 41 of the first partial piston 9. The second partial pistons 36 are here provided in pairs, and have a shorter length 1 than the third partial pistons, which have the larger length 1′.

[0092] Even if the second and third partial pistons 36 or 37 are each shown with the same diameter in terms of their paired configuration, but also each viewed separately, they can also have varying diameters.

[0093] As shown, the second partial pistons 36 and the third partial pistons 37 in this embodiment each preferably have a flange 42, 43 on the bottom side, with which they can also come to abut against a corresponding surface of the partial piston in an extended position. In this embodiment as well, the flanges 42, 43 are hydraulically not included in the impact surfaces.

[0094] The transfer surfaces of the second and third partial pistons 36, 37 are uniformly assigned here with the reference 20″.

[0095] An outer edge 44 of the impact surface of the first partial piston 9 in this exemplary embodiment is provided so as to coincide with an inner surface of the hydraulic cylinder. With respect to the geometric central azis A, the impact surfaces of the second and third partial pistons 36, 37 are not to be included, wherein no difference would arise here either owing to the symmetrical arrangement.

[0096] All disclosed features (whether taken separately ox in combination with each other) are essential to the invention. The disclosure of the application hereby also incorporates the content the disclosure of accompanying/attached priority documents (copy of the prior application) in its entirety, also for the purpose of including features of these documents in claims of the present application. Even without the features of a referenced claim, the subclaims characterize standalone inventive further developments of prior art with their features, in particular so as to submit partial applications based upon these claims. The invention indicated in each claim can additionally have one or several of the features indicated in the above description, in particular those provided with reference numbers and/or indicated on the reference list. The invention also relates to design forms in which individual features specified in the above description are not realized, in particular if they are recognizably superfluous with regard to the respective intended use, or can be replaced by other technically equivalent means.

TABLE-US-00001 REFERENCE LIST  1 Working device  2 Accumulator  3 Motor  4 Gearbox  5 Pump  6 Hydraulic cylinder  7 Storage space  3 Activating switch  9 First partial piston 10 Second partial piston 11 Piston rod 12 Working head 13 First tool 14 Second tool 15 Crimping opening 16 First impact surface 17 Second impact surface 18 Overall impact surface 19 Transfer surface 20 Transfer surface 20′ Transfer surface 20″ Transfer surface 21 Stop 22 Return spring 23 Impact flange 24 First gasket 25 Second gasket 26 Threaded connection 27 Locking screw 28 Sleeve part 29 Third partial piston 30 Stop flange 31 Impact surface 32 Flange 33 Circular impact surface 34 Stop 25 Stop 36 Second partial piston 37 Third partial piston 38 Bore-like receiving opening 39 Bore-like receiving opening 40 Bore-like receiving opening 41 Bore-like receiving opening 42 Flange 43 Flange 44 Outer edge 45 Cylinder cover 46 Cylinder floor 47 Partial cylinder wall l Length l′ Length A Central azis V Traversing direction