TOOL

Description

State of the art

[0001] Hand-held or hand-operated tools used in joining technology, for example for pressing, expanding, bending, or cutting, are known, wherein the tool for moving a tool attachment comprises a cylinder and a piston received in the cylinder and movable in a working direction relative to the cylinder. The piston can be coupled to the tool attachment. Such a tool is known, for example, from WO 2017 / 025379 A1.

[0002] Such tools include, for example, an electro-hydraulic drive unit that moves the piston in the working direction during one work step. During operation, the piston undergoes a driven movement relative to the cylinder, with a spring unit housed inside the cylinder providing the necessary force for a subsequent work step or for returning the piston to the opposite working direction. This is based on the principle of a single-acting cylinder.

[0003] The tool attachment of the respective tool can be detachably connected by moving the piston. Preferably, exactly one tool attachment from several different tool attachments is selectively connected to the piston in order to move the tool attachment together with the piston. Purpose and advantages of the invention

[0004] The object of the present invention is to provide a hand-held tool of the type mentioned above, which is designed to be improved with regard to practical use, in particular a tool that is more compact and with which the flexible use of different tool attachments in application is facilitated.

[0005] This problem is solved by the independent claims. The dependent claims address advantageous and expedient further developments of the invention.

[0006] The invention relates to a tool for hand-held use, in particular a crimping, expanding, bending and / or cutting tool, with a single-acting cylinder and a piston received in the cylinder and movable in a working direction relative to the cylinder, wherein the tool comprises an electro-hydraulic drive unit for driving the piston in the working direction, wherein during operation of the tool the piston experiences a driven movement relative to the cylinder, and wherein a spring unit housed within the cylinder is provided for returning the piston against the working direction, wherein the piston is detachably connected to a tool attachment of the tool, so that selectively exactly one tool attachment from several different tool attachments can be connected to the piston.The tool attachment, which forms the actual outward-acting part of the tool and serves as the workpiece, such as a section of plumbing pipe, is preferably indirectly connected to the piston. A tool attachment can be, for example, a crimping yoke, a sliding fork, a cutting attachment, an expanding mandrel, or a bending attachment. Such tools are used, for example, as special tools in the plumbing sector. In addition to the tool attachment that moves with the piston, the tool typically has another tool attachment, with at least one workpiece or element positioned between the two tool attachments for machining.

[0007] The spring unit preferably comprises a compression spring, in particular a pre-tensioned compression spring such as a helical compression spring.

[0008] The piston preferably comprises a piston element and a piston rod. The piston, or at least the piston element of the piston, which with a first axial side of the piston element fills a cross-section of the cylinder and in particular adjoins a hydraulic chamber of the cylinder, is hydraulically sealed and guided over its stroke by means of a sealing arrangement such as a ring seal on the tool or in the cylinder. The other side of the piston element is preferably connected to a piston rod of the piston, which extends inside the cylinder on a side where no hydraulic fluid is located.

[0009] The electro-hydraulic drive unit includes, for example, a battery-powered hydraulic pump for pumping hydraulic fluid from a storage volume into a hydraulic chamber within the cylinder. The volume of the hydraulic chamber is preferably variable, depending on the position of the piston in the cylinder.

[0010] One aspect of the invention is that a receptacle is provided outside the cylinder, the receptacle being connected to the piston and remaining attached to the cylinder for operation with different tool attachments. Quick-release fasteners are provided between the receptacle and a tool attachment such that a tool attachment can be attached to the receptacle without tools. The receptacle, which is slidably located on the outside of the cylinder and is preferably provided with a sliding coating for this purpose, is part of the tool. The receptacle has external sections, located on the outside of the tool, to which a tool attachment is made. The receptacle is preferably a tool element that surrounds the cylinder externally over a partial axial length, such as a sleeve section attached to the outside of a cylinder shell.

[0011] With the mount that remains permanently attached to the cylinder and thus to the tool, and the quick-release fasteners integrated into both the mount and the respective tool attachment, an improvement over previous tools has been achieved. Previously, each tool attachment was connected using a detachable fastener, such as a plug-in element, which e.g.The connection created by the piston and the tool holder is detachable. This has several disadvantages, which are prevented by the present invention. For example, in practical use, a disconnected connector is regularly misplaced or lost. Furthermore, the connector is often dirty or damaged when not in use, as it is not attached to the tool and is therefore unprotected. It is also cumbersome and time-consuming to remove the connector every time a tool attachment is changed and then reinsert it for the new or next used tool attachment. With quick-connect devices, changing the tool attachment is done with a simple manual movement, for example, in just a few seconds.

[0012] The quick-release fasteners can be designed to be very compact and captive, particularly protected against external damage, at the mounting point and on the tool attachment. The quick-release fasteners comprise a locking mechanism with, for example, a spring-loaded locking section that engages with spring tension in a locking contour upon achieving the connection state. The quick-release fastener is secured by a releasable locking mechanism. e.g. Manually releasable. For example, by making the spring-loaded detent section preferably manually movable from its detent position to a release position. This can be achieved, for example, by a relative movement of the receptacle to the cylinder, whereby a minimum force and / or a minimum torque must be applied or overcome in a release direction.

[0013] The quick-release fasteners feature, for example, a locking mechanism formed by a ball detent. The quick-release fasteners preferably also serve as a rotation lock for the tool attachment relative to the cylinder. The quick-release fasteners preferably include a spring-loaded guide pin that engages in a guide groove and runs along the guide groove until it reaches a point in the guide groove that forms a detent for the guide pin, which snaps into place when a connection position is reached.

[0014] The invention also relates to the cylinder having a first axial end face and a second axial end face opposite the first axial end face, wherein the piston comprises a piston element guided against an inner surface of the cylinder shell, with a first axial side of the piston element adjoining a hydraulic chamber located in the cylinder and bounded by the first end face of the cylinder, wherein the spring unit is located in a region between the second end face of the cylinder and a section of the piston facing away from the first axial side of the piston element, the section of the piston facing the second axial end face of the cylinder. The spring unit is preferably clamped between the second end face of the cylinder and a section on the piston rod. The piston orThe piston element is movable back and forth inside the cylinder, separating a hydraulic chamber from a non-hydraulic chamber within the cylinder. The size of the two chambers, or rather the separation between the hydraulic and non-hydraulic chambers, depends on the current position of the piston element within the cylinder.

[0015] A piston rod preferably projects from the second side of the piston element. Accordingly, the spring unit or compression spring preferably extends with one end to the piston rod. The piston rod projects in the working direction, i.e., in the direction in which the piston executes a working stroke.

[0016] The spring unit, or helical compression spring, is preferably clamped between the second axial side of the piston element and the second end face of the cylinder. The length of the spring unit, or compression spring, depends on the position of the piston in the cylinder and / or the distance between the second axial side of the piston element and the second end face of the cylinder. Depending on the position of the piston element in the cylinder, the length of the compression spring is determined during operation of the tool and is compressed to varying degrees.

[0017] This allows the tool construction length between the tool attachments, and thus a practically relevant tool size dimension, to be reduced, since the spring unit can be reduced to a storage length or compressed to its minimum length.

[0018] The cylinder is stationary on the tool and does not move with the drive unit. The single-acting cylinder, or hydraulic cylinder, is only pressurized with hydraulic fluid on one side of the piston, and work is performed in only one direction.

[0019] It is also advantageous that the piston has a piston rod which projects from the side of the piston element facing away from the hydraulic chamber towards the second end face of the cylinder. The piston rod is advantageously located in a chamber inside the cylinder that is not filled with hydraulic fluid. The tool attachment is connected to the piston or its piston rod, which together with the piston element forms the piston, for example, at an axial point on the piston rod that is located away from the piston element along its substantial length, or in the region of a free end of the piston rod.

[0020] Advantageously, the spring unit is located in an area between the second end face of the cylinder and an end area of ​​the piston rod facing away from the piston element.

[0021] The spring unit is preferably supported at one end against the end of the piston rod and at the other end against the second, axial inner face of the cylinder. The spring unit, or compression spring, is clamped or pre-tensioned. This ensures that a restoring force is always provided to return the piston to the opposite direction of travel within the cylinder. This restoring force comes into effect when the opposing force due to the hydraulic pressure on the first axial side of the piston element is less than the opposing spring force on the other axial side of the piston.

[0022] Furthermore, it is advantageous if a connecting element is provided for connecting the piston rod and the receiver, which extends through the piston rod to an end area of ​​the piston rod facing away from the piston element.

[0023] The connection between the piston rod and the receptacle is provided, for example, by a connecting element, such as a plug-in connector, that extends radially through the piston rod. Preferably, both ends of the connecting element or plug-in connector, which protrude beyond the outer surface of the cylinder, engage in a corresponding recess, opening, or notch on the receptacle. For this purpose, the receptacle has two diametrically opposed openings for the straight, elongated connecting element or plug-in connector. The respective longitudinal ends of the plug-in connector, e.g., flat end faces, are preferably flush with or slightly countersunk on the outer surface of the receptacle. To allow the connector to pass through and overcome the reciprocating motion of the piston and thus the receptacle, the cylinder wall has two longitudinally elongated, opposing openings or passages, such as two elongated slots.The plug-in element is, for example, a plug-in pin such as a cylindrical plug-in pin.

[0024] An advantageous variant is characterized by the fact that the piston and the receptacle can be connected with a connecting element designed as a plug-in element, wherein the plug-in element extends transversely to the working direction through the cylinder and reaches into a recess of the receptacle.

[0025] The depression is preferably an opening such as a through-hole or a recess.

[0026] According to another advantageous embodiment, a fixed tool attachment can be detachably mounted on the cylinder in the region of the second axial end face of the cylinder, wherein the mounted fixed tool attachment is positionally fixed on the cylinder during operation of the tool. Thus, relative movement occurs between the tool attachment and the fixed tool attachment during operation. The fixed tool attachment is, in particular, a tool attachment that, when mounted externally on the cylinder during operation of the tool, is positionally fixed relative to the cylinder in the axial direction or in the working direction. For the tool function or for work to be performed with the tool, the fixed tool attachment interacts with the movable tool attachment mounted on the holder. A workpiece, such as a pipe section and a press fitting that can be pressed onto it, is located between the two tool attachments.

[0027] Furthermore, an advantage arises from the fact that the tool attachment is designed as a bending tool attachment, a pressing tool attachment, an expanding tool attachment, and / or a cutting tool attachment. This provides a flexibly applicable tool, preferably a combination tool with one or at least two combined tool functions according to the aforementioned tool attachment variants, whereby the basic tool body, i.e., the predominant part of the tool without the tool attachment, is the same or universally usable for all variants. Preferably, the different tool attachments each have the same sections of quick-release fasteners for tool-free attachment to the holder.

[0028] Advantageously, the tool attachment can be secured to the holder and / or radially fixed via a locking element. Preferably, the tool attachment is fixed to the holder radially and axially, preferably rigidly, by at least one locking element. This ensures that the tool attachment remains securely and firmly fixed to the tool even under load during operation, thus providing highly reliable tool function. A locking element is, for example, a spring-loaded pin or cylindrical pin that projects radially inwards from the tool attachment and engages in a corresponding groove in the holder. The groove runs along the outside of the holder in the working direction or longitudinal direction of the cylinder.

[0029] Following a modification of the invention, the fixed tool attachment can be detachably mounted on the cylinder via a bayonet connector. Bayonet connectors provide a proven connection method, whereby the connection can be securely set up with a simple movement and can be released again after, for example, a manual unlocking process.

[0030] Advantageously, the bayonet connectors are designed such that the fixed tool attachment can only be positioned in exactly one circumferential position on the cylinder relative to the working direction. This allows the fixed tool attachment, even if it has two or more different, circumferentially offset, individually acting tool sections, to be mounted in a desired, precise, and in particular, precisely circumferential orientation on the tool or on the outside of the tool cylinder.

[0031] Another advantage is that the bayonet connectors include a locking mechanism for securing the fixed tool attachment to the cylinder. With an audible or tactile click, for example, a secure and permanent connection is established. The locking mechanism can feature a spring-loaded locking element and a corresponding locking contour that interacts with the locking element, present on both the cylinder and the fixed tool attachment.

[0032] This enables a stable and reliably installed releasable locking mechanism. Character description

[0033] Further features and advantages of the invention are explained below with reference to a partially schematic embodiment. Specifically, the following is shown: Fig. 1 a perspective exploded view of a part of a tool according to the invention, taken obliquely from the side, Fig. 2 the part of the tool according to Fig. 1 in side view, with indicated inner contours, Fig. 3 the part of the assembled tool in side view according to Fig. 2 in longitudinal section and Fig. 4 the part of the assembled tool according to Fig. 3 in a longitudinal section along line AA in Fig. 3 .

[0034] The figures show a tool head 2 of a hand-held tool according to the invention, which is designed as a crimping tool 1. The crimping tool 1 as a whole is shown in Fig. 3 indicated, with a schematic outline of a hand-operating section 3 of the crimping tool 1 shown in dashed and interrupted lines below the specifically depicted tool head 2.

[0035] The tool head 2 can be assembled from individual tool elements. The tool head 2 comprises a hydraulic fluid supply 4, designed as an oil supply, ring components 5, a piston 6 with a piston element 7 and a piston rod 8, an O-ring 9, a spring unit 10, a hollow cylinder 11, a threaded ring 12, a receptacle 13, a connecting element 14, designed as a plug-in element 15, a movable tool attachment 16, and a fixed tool attachment 18. The movable tool attachment 16 is designed as a crimping yoke 17, and the fixed tool attachment 18 is designed as a crimping yoke 19. The crimping yoke 17 has three circumferentially offset fork sections 17a, each with a different fork width. Similarly, the crimping yoke 19 has three circumferentially offset fork sections 19a, each with a different fork width (see figure). Fig. 1 ).

[0036] The cylinder 11 has a first axial end face 11a and a second axial end face 11b. The piston element 7 has a first axial side 7a, which faces the first axial end face 11a of the cylinder 11. The piston 6 has a section 6a facing away from the first axial side 7a of the piston element 7, with the section 6a of the piston 6 facing the second axial end face 11b of the cylinder 11.

[0037] The ring components 5 include two O-rings, two support rings, a groove ring and a retaining ring.

[0038] The piston element 7 and the piston rod 8 are screwed tightly together.

[0039] The spring unit 10 shown schematically is preferably designed as a helical compression spring.

[0040] The grouting tool 1 comprises an electro-hydraulic drive unit for driving the piston 6 and thus the grouting yoke 17 in the working direction P1, wherein the drive unit, which is not shown, is essentially housed in the manual operating section 3.

[0041] In the single-acting hollow cylinder 11, the piston 6, which is movable in the working direction P1 and in the opposite direction P2 relative to the cylinder 11, is linearly displaceable and guided. The cylinder 11 is closed at one axial end, where the pressing yoke 19 is mounted externally, by a base that is integrally formed with the rest of the cylinder 11. The other open end of the cylinder 11 is closed by the hydraulic fluid supply 4.

[0042] The spring unit 10, which is also housed inside the cylinder 11, is responsible for returning the piston 6 to the return direction P2.

[0043] The piston rod 8 is connected to the receptacle 13 by means of the cylindrical plug-in element 15. For this purpose, two diametrically opposed matching holes or round holes 20, 21 are provided in the area of ​​a free end of the piston rod 8, and two opposing holes or round holes 22, 23 are provided in the receptacle 13, which the plug-in element 15 fills. The plug-in element 15 also engages through two opposing openings 24, 25 in the wall of the hollow cylinder 11, the two openings 24, 25 being designed as elongated holes.

[0044] Furthermore, quick-release fasteners 26 are provided between the receptacle 13 and the tool attachment 16, so that the tool attachment 16 can be detachably and attached to the receptacle 13 without tools. The quick-release fasteners 26 have a locking element 27 with which the tool attachment 16 can be fixed to the receptacle 13, preferably in the longitudinal direction of the cylinder 11 or radially.

[0045] The tool attachment 17 is, for example, pushed onto the cylinder 11 and held in place by locking pieces.

[0046] For example, the tool attachment 17 on the cylinder 11 can also be detachably but securely attached manually to the cylinder 11 via quick-release fasteners 28, which are preferably designed as bayonet fasteners 29. The bayonet fasteners 29 include, for example, a locking mechanism for locking the tool attachment 17 to the cylinder 11. For this purpose, a circumferential annular groove 30 is formed at the end of the cylinder 11 with a flat groove base and a first wall or flank oriented perpendicular to the groove base and an opposing second wall oriented at an angle greater than 90 degrees to the groove base.

[0047] In the Fig. 3 and 4Figure 1 shows a situation or a basic position of the crimping tool 1 or the tool head 2, in which, under the action of the spring unit 10 pre-tensioned in the cylinder 11, the piston 6 and thus the receptacle 13 and the crimping yoke 17 are moved away from the crimping yoke 17 in the return direction P2.

[0048] Starting from the initial position of the crimping tool 1, the drive unit of the hand-operated crimping tool is actuated by manually acting on the hand control section 3 for a working stroke or for the movement of the piston 6 in the working direction P1. Hydraulic fluid stored in an accumulator in the hand control section 3 is pumped through an opening 33 on the hydraulic fluid supply 4 into a hydraulic line 31 in the hydraulic fluid supply 4 in the direction P0. The pumping process is carried out by a preferably battery-powered hydraulic fluid pump in the hand control section 3. Hydraulic fluid flows via the hydraulic line 31 into a hydraulic chamber 32 in the tool head 2 between an inner side of the hydraulic fluid supply 4 and a first axial side of the piston element 7, which faces away from or opposite the axial side of the piston element 7 with the piston rod.The hydraulic pressure acting in the hydraulic chamber 32, for example with continuously pumped hydraulic fluid, moves the piston element 7 and thus the piston rod 8, the receptacle 13 and the crimping yoke 17 in the working direction P1. The spring unit 10 is thereby reduced in length or compressed more. Under the hydraulically applied force, a crimp fitting (not shown) attached to a pipe (not shown) is pressed onto the pipe. The corresponding pipe section with crimp fitting is first inserted between the two separated crimping yokes 17 and 19, each on longitudinally aligned, paired fork sections 17a and 19a.

[0049] For guiding and inserting the press fitting and the pipe, a respective fork section 17a or 19a is provided on the crimping yokes 17 and 19. To accommodate different pipe and press fitting diameters, three different fork sections 17a and 19a, each adapted to a specific pipe diameter, are positioned offset by their circumferences on the crimping yokes 17 and 19. Depending on the pipe diameter, the crimping yokes 17 and 19 are attached to the receptacle 13 or the cylinder 11 in the correct circumferential position, with the corresponding fork sections 17a and 19a aligned linearly. This is achieved using the quick-connect fasteners 26 and 28, respectively.

[0050] After a work step, hydraulic fluid is forced from the hydraulic chamber 32 in the opposite direction P0 towards the accumulator by operating the manual control section 3. This occurs under the pressure of the previously further tensioned spring unit 10. The crimping yoke 17 is then returned to its original position in the direction of P2. The crimping tool 1 is removed from the workpiece. Reference symbol list

[0051] 1 Crimping tool 2 Tool head 3 Hand operating section 4 Hydraulic fluid supply 5 Ring components 6 Piston 6a Section 7 Piston element 7a Side 8 Piston rod 9 O-ring 10 Spring unit 11 Cylinder 11a, 11b End face 12 Threaded ring 13 Mount 14 Connecting element 15 Plug-in element 16 Tool attachment 17 Crimping yoke 17a Fork section 18 Tool attachment 19 Crimping yoke 19a Fork section 20, 21 Round hole 22, 23 Round hole 24, 25 Passage 26 Quick-release fastener 27 Locking element 28 Quick-release fastener 29 Bayonet fastener 30 Ring groove 31 Hydraulic line 32 Hydraulic chamber 33 Opening

Claims

1. Tool for handheld tool use, in particular a crimping tool (1), an expanding tool, a bending tool and / or a cutting tool, having a single-acting cylinder (11) and a piston (6) accommodated in the cylinder (11) and movable in a working direction relative to the cylinder (11), wherein the tool comprises an electro-hydraulic drive unit for driving the piston (6) in the working direction, wherein, during operation of the tool, the piston (6) undergoes a driven movement relative to the cylinder (11), and wherein, for resetting the piston (6) counter to the working direction, a spring unit (10) accommodated within the cylinder (11) is provided, wherein the piston (6) is releasably connectable to a tool attachment (16, 18) of the tool, so that, optionally, exactly one tool attachment (16, 18) of a plurality of different tool attachments can be connected to the piston (6), wherein a receptacle (13) is provided outside the cylinder (11), wherein the receptacle (13) is connected to the piston (6) and remains on the cylinder (11) for operation of the tool with different tool attachments, wherein between the receptacle (13) and a tool attachment (16) quick-connection means (26) are designed such that a tool attachment (16) can be mounted on the receptacle (13) without tools, characterized in that the quick-connection means (15) comprise a latching arrangement with a resilient latching section which engages in a latching contour in a resiliently prestressed manner, and a piston rod (8) is connected to the receptacle (13) by means of a cylindrical plug-in element (15), and in the region of a free end of the piston rod (8) two diametrically opposite matching holes or round holes (20, 21) are provided and in the receptacle (13) two opposite holes or round holes (22, 23) are provided, which are filled by the plug-in element 15, wherein the plug-in element (15) engages through two opposite passages (24, 25) in the wall of the hollow cylinder (11), wherein the two passages (24, 25) are designed as elongated holes.

2. Tool according to claim 1, characterized in that the cylinder (11) has a first axial end face (11a) and a second axial end face (11b) opposite the first axial end face (11a), wherein the piston (6) comprises a piston element (7) guided in contact with an inner side of the cylinder jacket, with a first axial side (7a) of the piston element (7) which adjoins a hydraulic chamber (32) present in the cylinder (11) and bounded by the first end face (11a) of the cylinder (11), wherein the spring unit (10) is accommodated in a region between the second end face (11b) of the cylinder (11) and a section (6a) of the piston (6) facing away from the first axial side (7a) of the piston element (7), wherein the section (6a) of the piston (6) faces toward the second axial end face (11b) of the cylinder (11).

3. Tool according to claim 2, characterized in that the piston (6) has a piston rod (8) which projects, on a side of a piston element (7) facing away from the hydraulic chamber (32), in the direction of the second end face of the cylinder (11).

4. Tool according to claim 2 or claim 3, characterized in that the spring unit (10) is accommodated in a region between the second end face of the cylinder (11) and an end region of the piston rod (8) facing away from the piston element (7).

5. Tool according to one of claims 2 to 4, characterized in that in the region of the second axial end face of the cylinder (11) a fixed tool attachment (18) can be releasably mounted on the cylinder (11), wherein the mounted fixed tool attachment (18) is present in a position-fixed manner on the cylinder (11) during operation of the tool.

6. Tool according to one of the preceding claims, characterized in that the tool attachment (16, 18) is designed as a bending tool attachment and / or as a pressing tool attachment and / or as an expanding tool attachment and / or as a cutting tool attachment.

7. Tool according to one of the preceding claims, characterized in that the tool attachment (16, 18) can be secured and / or radially fixed to the receptacle (13) by means of a securing element (27).

8. Tool according to claim 5, characterized in that the fixed tool attachment (18) can be releasably mounted on the cylinder (11) via bayonet connection means (29).

9. Tool according to claim 8, characterized in that the bayonet connection means (29) are designed such that positioning of the fixed tool attachment (18) on the cylinder (11) is possible in only exactly one circumferential position relative to the working direction.

10. Tool according to claim 8 or claim 9, characterized in that the bayonet connection means (29) comprise a latching mechanism for latching the fixed tool attachment (18) on the cylinder (11).