Actuation device for a portable tool

Abstract

An actuating device (1) for a portable tool (2) comprising a tank (3) of hydraulic fluid, a hydraulic actuator (4) with a piston (6) and a cylinder (5) formed by a cylinder body (51), a hydraulic pump (8) drivable by an electric motor (9) of the portable tool (2) for actuating the hydraulic actuator (4), a transmission member (10) extending from the hydraulic actuator (4) to transmit a movement of the hydraulic actuator (4) to a working head (16), a pump module (80) comprising: – a pump body (87) forming a pump cylinder (81), a first valve seat (88), and a second valve seat (89) of the hydraulic pump (8), – the suction check valve (83) in the first valve seat (88), – the delivery check valve (85) in the second valve seat (89), wherein the pump module (80) is inserted in the hydraulic cylinder (5), wherein the pump module (80) delimits, together with the hydraulic piston (5) and the cylinder body (51), a pressure chamber (52) of the cylinder (5).

Description

“Actuation device for a portable tool"DESCRIPTION

[0001] The invention relates to an actuation device for a portable tool, for example a compression or cutting tool, comprising a drive consisting of an electric motor and a hydraulic unit with a hydraulic pump actuated by the electric motor, a cylinder-piston unit pressurised by the hydraulic pump, and a hydraulic fluid tank.

[0002] Portable tools are known, for example, for connecting pipe ends by means of press fittings and for fixing cable lugs to electrical cables. To this end, portable tools comprise, in addition to the actuation device, a working head with, for example, two pressing jaws adapted to the respective intended use.

[0003] During the pressing process, the hydraulic fluid drawn from the tank by means of the hydraulic pump and introduced into a pressure chamber of the cylinder-piston unit causes a guided linear movement of a piston relative to a cylinder of the cylinder-piston unit. The piston interacts with the working head, for example by means of an interposed actuation rod, so as to move the pressing jaws in a pressing direction.

[0004] Hydraulic actuation devices comprise a significant number of structures, moving members, cavities and ducts made to operate the circulation of the hydraulic fluid and the movements of the hydraulic pump and the piston in the planned manner. Such structures, members, ducts and cavities may comprise, according to the inventors (and not with reference to a known embodiment), a cylindrical cavity of a cylinder-piston pumping unit of the hydraulic pump, a piston of the hydraulic pump, suction and delivery non-return valves of the hydraulic pump, communication channels between the pressure chamber and a seat for a pressure sensor, a filling and purging channel of a tank space with an associated closing member, a filling and purging channel of the pressure chamber with an associated closing member, a maximum pressure valve, a manual release valve of the actuation device.

[0005] The realization of these structures, ducts, cavities and members within the limited available spaces requires complex and costly machining of the cylinder body of the cylinderpiston unit, as well as the manufacture of the entire cylinder body in steel or the use of special steel inserts to be screwed into the cylinder body made of a metallic material other than steel, for example aluminium, in order to allow the non-return valves to be screwed in with the necessary tightening force and ensuring the non-deformability of the body-valve sealing areas.

[0006] There is therefore a need to facilitate and simplify the machining and assembly of the hydraulic cylinder-piston unit. There is also a need to be able to make a lighter cylinder body and at the same time less expensive than a body made of steel, considering the best compromise between the mechanical properties of the raw material, the machining and the assembly.

[0007] The realization of the aforementioned structures, ducts, cavities and members in the cylinder body of the cylinder-piston unit is also penalising with reference to the radial bulk of the actuation device, which leads, as a consequence, to a reduced volume available for the hydraulic fluid tank or to space problems for a gripping area of the portable tool, which is frequently (in “in-line” or torch-shaped tools) made around the hydraulic actuation device.

[0008] A particularly bulky structure in this context is the maximum pressure valve which, in order to remain open during a discharge phase of hydraulic fluid from the pressure chamber of the hydraulic cylinder into the tank, is often configured as a “floating” valve with a relatively wide shutter.

[0009] There is therefore a need to make better use of the spaces occupied by the actuation device and to contain its radial bulk with equal size of the individual functional accessories, such as for example the maximum pressure valve.

[0010] A further unsatisfied need in known portable tools is to better reconcile the spaces occupied by the hydraulic fluid tank, by the handle of the tool and by actuation and / or release members of the portable tool that can be manually operated by the user.

[0011] Also with reference to the cost, weight, bulk and machining complexity of components of the portable tool, there is a need to configure the working head as favourably as possible. With reference to a known embodiment, in which two jaws are engaged and moved by two rollers which are in turn displaced by the movement of the hydraulic piston, it is known to make a fork in solid metal that supports the jaws and guides the movement of the two rollers. Since the jaw support regions and the roller guiding regions extend at a distance from one another, the fork of the known technique is undesirably large and requires a considerable quantity of metallic material (therefore, weight, costs) even in regions of the working head which would not require particular mechanical resistance.

[0012] The purpose of the present invention is to provide an actuation device for a portable tool and a portable tool having characteristics such as to overcome at least some of the drawbacks of the prior art.

[0013] Within the general purpose, particular purposes of the invention are:

[0014] - to facilitate and simplify the machining and assembly of the hydraulic cylinder-piston unit,

[0015] - to make a lighter and overall less expensive cylinder body, without however making the machining and assembly more costly and complex,

[0016] - to make better use of the spaces occupied by the actuation device and to contain its radial bulk with equal size of the individual functional accessories, such as for example the maximum pressure valve,

[0017] - to better reconcile the spaces occupied by the hydraulic fluid tank, by the handle of the tool and by actuation and / or release members of the portable tool that can be manuallyoperated by the user,

[0018] - to reduce the costs and the weight of the working head and / or to simplify its manufacture.

[0019] At least some of these purposes are achieved by means of an actuation device for a portable tool according to claim 1. The dependent claims relate to advantageous embodiments.

[0020] According to an aspect of the invention, an actuation device 1 for a portable tool 2, for example a compression tool, comprises:

[0021] a hydraulic fluid tank 3,

[0022] a hydraulic actuator 4 having a hydraulic cylinder 5 formed by a metal cylinder body 51, a hydraulic piston 6 accommodated in a guided manner in the hydraulic cylinder 5 and dividing the hydraulic cylinder 5 into a pressure chamber 52 and a rear chamber 53 on a rear side 7 of the hydraulic cylinder 5,

[0023] a hydraulic pump 8 actuatable by an electric motor 9 of the portable tool 2 and having a pump cylinder 81, a pumping piston 82 guided in the pump cylinder 81, a non-return suction valve 83 defining a suction passage 84 of the hydraulic fluid from the tank 3 into the pump cylinder 81, a non-return delivery valve 85 defining a delivery passage 86 of the hydraulic fluid from the pump cylinder 81 into the pressure chamber 52 of the hydraulic cylinder 5 to actuate the hydraulic actuator 4,

[0024] a transmission member 10 extending from the hydraulic piston 6 on the rear side 7 to transmit a movement of the hydraulic piston 6 to a working head 16 of the portable tool 2,

[0025] a pump module 80 comprising:

[0026] - a pump body 87 forming the pump cylinder 81 , a first valve seat 88 and a second valve seat 89,

[0027] - the non-return suction valve 83 screwed into the first valve seat 88,

[0028] - the non-return delivery valve 85 screwed into the second valve seat 89,

[0029] wherein the pump module 80 is inserted into the hydraulic cylinder 5 from the rear side 7 in a front bottom region 54 of the hydraulic cylinder 5, opposite to the rear side 7,

[0030] wherein the pump module 80 delimits, together with the hydraulic piston 5 and the cylinder body 51 , said pressure chamber 52.

[0031] With further advantage, the cylinder body 51 is made of a material lighter than the material of the pump body 87, for example aluminium, and the pump body 87 is made of a mechanically more resistant material (intended as: having greater hardness and / or higher elastic modulus and / or higher yield strength and ultimate strength) than the material of the cylinder body 51 , for example steel.

[0032] The proposed configuration allows the cylinder body 51 (which has significant dimensions) to be manufactured in an overall more economical manner and using a lightermaterial predominantly suitable to ensure sealing and sliding of the hydraulic piston 6, but not necessarily sufficiently resistant both for the fixed screwing of the non-return valves and for their reliable hydraulic sealing and for the guiding / sliding of the pumping piston without wear, for example aluminium or aluminium alloy.

[0033] The proposed configuration further allows the valve seats 88, 89 to be manufactured in a material (e.g. steel) sufficiently resistant for the purpose, without however using large quantities of the resistant material, which is heavier and requires more costly machining.

[0034] The proposed configuration further allows, before insertion of the pump module 80 into the hydraulic cylinder 5, excellent accessibility to all external sides of the pump body 87 and therefore a simplification of the mechanical machining to create the three-dimensional anatomy of the hydraulic pump 8, as compared with its realization in the cylinder body 51.

[0035] Furthermore, the proposed configuration reduces the number and simplifies the shape of the access cavities to the hydraulic pump, to be realized directly in the cylinder body 51.

[0036] Finally, the proposed configuration, at the cost of a (only) axial lengthening of the cylinder body 51 and of the hydraulic cylinder 5, moves the components of the hydraulic pump 8 into a region of easy placement (inside the hydraulic cylinder 5), overcoming the drawbacks (bulk, space conflicts with other structures and functions, etc.) of a positioning of the hydraulic pump 8 externally to the hydraulic cylinder 5.

[0037] It is noted in particular that the pump body 87 can be realized starting from a simple round profile, for example of steel.

[0038] According to a further aspect of the invention, an actuation device 1 for a portable tool 2, for example a compression or cutting tool, comprises:

[0039] a hydraulic fluid tank 3,

[0040] a hydraulic actuator 4 having a hydraulic cylinder 5 formed by a metal cylinder body 51, a hydraulic piston 6 accommodated in a guided manner in the hydraulic cylinder 5 and dividing the hydraulic cylinder 5 into a pressure chamber 52 and a rear chamber 53 on a rear side 7 of the hydraulic cylinder 5,

[0041] a hydraulic pump 8 actuatable by an electric motor 9 of the portable tool 2 and having a pump cylinder 81, a pumping piston 82 guided in the pump cylinder 81, a non-return suction valve 83 defining a suction passage 84 of the hydraulic fluid from the tank 3 into the pump cylinder 81, a non-return delivery valve 85 defining a delivery passage 86 of the hydraulic fluid from the pump cylinder 81 into the pressure chamber 52 of the hydraulic cylinder 5 to actuate the hydraulic actuator 4,

[0042] a transmission member 10 extending from the hydraulic piston 6 on the rear side 7 to transmit a movement of the hydraulic piston 6 to a working head 16 of the portable tool 2,

[0043] a maximum pressure valve 17 positioned in a release duct 171 of the hydraulic fluid from the pressure chamber 52 into the tank 3,

[0044] wherein:

[0045] - the release duct 171 comprises a release inlet 172 formed in the hydraulic piston 6 and facing the pressure chamber 52 and a release outlet 173 in communication with the tank 3, and

[0046] - the maximum pressure valve 17 comprises a valve seat 174 formed in the release duct 171 in the hydraulic piston 6 and a release shutter 175 extending into the hydraulic piston 6.

[0047] The realization (of part) of the release duct 171 and the positioning of the maximum pressure valve 17 in the hydraulic piston 6 allow better use of the spaces available within the actuation device 1.

[0048] Furthermore, the good accessibility to all external sides of the hydraulic piston 6, before its insertion into the hydraulic cylinder 5, simplifies the mechanical machining to make the release inlet 172, the release duct 171 , the valve seat 174 and the accommodation space of the release shutter 175, as compared with their realization in the cylinder body 51.

[0049] According to a further concept of the invention, a portable tool 2, for example a compression or cutting tool, comprises a working head 16 with a pair of jaws 18, and an actuation device 1 with:

[0050] a hydraulic fluid tank 3,

[0051] a hydraulic actuator 4,

[0052] a hydraulic pump 8 actuatable by an electric motor 9 of the portable tool 2 to actuate the hydraulic actuator 4,

[0053] a transmission member 10 extending from the hydraulic actuator 4 to transmit a movement of the hydraulic actuator 4 to the working head 16 to move the pair of jaws 18 between a first position (e.g. open) and a second position (e.g. closed or compression),

[0054] wherein the working head 16 comprises:

[0055] - a fork body 161 made of metal, for example aluminium alloy, which supports the jaws 18,

[0056] - a roller holder 162 connected with the transmission member 10 and supporting one or two rollers 163 in (rolling) contact with (at least one jaw 18 of) the pair of jaws 18,

[0057] - a guide surface system 164, 164' which at least partially surrounds the rollers 163, prevents the rollers 163 from falling out of the working head 16, and guides the rollers 163 along a drive stroke 165 (Figures 16, 17),

[0058] - a housing 166 made of polymer material connected externally around the fork body 161 and forming the guide surface system 164, 164' (Figures 1, 2, 15-18).

[0059] This configuration achieves a saving of metallic material, a reduction in weight and in metal machining operations at the cost of a production phase of polymer material (plastic, e.g. polyethylene, polyamide) injection moulding.

[0060] Brief description of the figures

[0061] To better understand the invention and appreciate its advantages, a description is provided below of some exemplary, non-limiting embodiments, with reference to the accompanying figures, in which:

[0062] figure 1 shows a portable tool, according to an embodiment,

[0063] figure 2 is a sectional view of a part (actuation device) of the portable tool in figure 1 ,

[0064] figures 3, 4, 5, 6, 7 are sectional views of details (including a pump module) of an actuation device for the portable tool, according to embodiments,

[0065] figures 8A, 8B, 8C, 8D are perspective views, partly in transparency (figures 8A, 8B), of a pump module of the actuation device, according to an embodiment,

[0066] figure 9 is an exploded view of the pump module of the actuation device, according to an embodiment,

[0067] figure 10 is a sectional view of a part (piston unit) of the actuation device of the portable tool in figure 2, in which a maximum pressure valve is in the closed position,

[0068] figure 11 is a sectional view of the actuation device of the portable tool in figure 2, in which the maximum pressure valve is in the open or floating position,

[0069] figures 12A, 12B are perspective views of a front piston body of the piston unit in figures 10 and 11 ,

[0070] figure 13 is a sectional view of a piston unit according to an embodiment,

[0071] figure 14 is an exploded view of the piston unit in figure 13,

[0072] figure 15 shows part of a working head of the portable tool in figures 1 and 2,

[0073] figure 16 is a longitudinal and perspective sectional view of the working head part in figure 15,

[0074] figure 17 is a cross-sectional view of the working head part in figure 15,

[0075] figure 18 is an exploded view of the working head part in figure 15.

[0076] Description of the actuation device 1 and of a portable tool 2

[0077] With reference to the figures, a (generic) portable tool 2 comprises a working head 16 with a pair of jaws 18, and an actuation device 1 with a hydraulic fluid tank 3, a hydraulic actuator 4, a hydraulic pump 8 actuatable by an electric motor 9 of the portable tool 2 to actuate the hydraulic actuator 4, and a transmission member 10 extending from the hydraulic actuator 4 to transmit a movement of the hydraulic actuator 4 to the working head 16 to move the pair of jaws 18 between a first position (open) and a second position (closed or compression).

[0078] An actuation device 1 for a portable tool 2 comprises:

[0079] a hydraulic fluid tank 3,

[0080] a hydraulic actuator 4 having a hydraulic cylinder 5 formed by a metal cylinder body 51, a hydraulic piston 6 accommodated in a guided manner in the hydraulic cylinder 5 anddividing the hydraulic cylinder 5 into a pressure chamber 52 and a rear chamber 53 on a rear side 7 of the hydraulic cylinder 5,

[0081] a hydraulic pump 8 actuatable by an electric motor 9 of the portable tool 2 and having a pump cylinder 81, a pumping piston 82 guided in the pump cylinder 81, a non-return suction valve 83 defining a suction passage 84 of the hydraulic fluid from the tank 3 into the pump cylinder 81, a non-return delivery valve 85 defining a delivery passage 86 of the hydraulic fluid from the pump cylinder 81 into the pressure chamber 52 of the hydraulic cylinder 5 to actuate the hydraulic actuator 4,

[0082] a transmission member 10 extending from the hydraulic piston 6 on the rear side 7 to transmit a movement of the hydraulic piston 6 to a working head 16 of the portable tool 2.

[0083] Description of the pump module 80

[0084] According to an aspect of the invention, the actuation device 1 comprises a pump module 80 comprising:

[0085] - a pump body 87 forming the pump cylinder 81 , a first valve seat 88 and a second valve seat 89,

[0086] - the non-return suction valve 83 screwed into the first valve seat 88,

[0087] - the non-return delivery valve 85 screwed into the second valve seat 89.

[0088] The pump module 80 is inserted into the hydraulic cylinder 5 from the rear side 7 in a front bottom region 54 of the hydraulic cylinder 5, opposite to the rear side 7. The pump module 80 delimits, together with the hydraulic piston 5 and the cylinder body 51, said pressure chamber 52.

[0089] According to an embodiment, the cylinder body 51 is made of a material lighter than the material of the pump body 87, for example aluminium, and the pump body 87 is made of a mechanically more resistant material (intended as: having greater hardness and / or higher elastic modulus and / or higher yield strength and ultimate strength) than the material of the cylinder body 51 , for example steel.

[0090] According to an embodiment, the second valve seat 89 and / or the delivery passage 86 are formed in a rear surface 870 of the pump body 87 facing the rear side 7 and facing the pressure chamber 52. The first valve seat 88 and / or the suction passage 84 are formed in a side surface 871 of the pump body 87 radially facing outwards (with respect to a central axis 12 of the hydraulic cylinder 5 corresponding to a central axis of the pump body 87). The pumping piston 82 extends from the outside of the hydraulic cylinder 5 into the pump cylinder 81, for example through an axial hole in a front wall of the cylinder body 51 and through an access opening 810 formed in a front surface 872 of the pump body 87 facing the front bottom 54 of the hydraulic cylinder 5 (Figures 3, 4, 7).

[0091] According to an embodiment, the pump module 80 comprises:

[0092] - a return channel 111 formed in the pump body 87 with a return inlet 112 facing thepressure chamber 52 and a return outlet 113 in communication with the tank 3, and

[0093] - a return valve 11 (which constitutes a manual return valve of the hydraulic piston 6 towards its stroke start position) with a valve seat 114 formed in the return channel 111 and a return shutter 115 accommodated in the pump body 87 and extending into the return channel 111,

[0094] - a control opening 116 formed in the pump body 87 for access (in the sense of passage and extension) of a control member 117, for example a rod, a button, etc., from the outside of the pump body 87 into engagement with the return shutter 115.

[0095] The realization of the return channel 111 and the positioning of the return valve 11 in the pump body 87 allows the valve seat 114 to be formed in a material sufficiently resistant for the purpose, without using large quantities of the resistant material, which, in the case of steel, is also very heavy.

[0096] The good accessibility to all external sides of the pump body 87 simplifies the mechanical machining to make the return inlet 112, the return outlet 113, the valve seat 114 and the control opening 116, as compared with their realization in the cylinder body 51.

[0097] Furthermore, the positioning of the return valve 11 in the pump module 80 inserted into the hydraulic cylinder 5 makes better use of the spaces available inside the actuation device 1.

[0098] According to an embodiment, the return inlet 112 is formed in a rear surface 870 of the pump body 87 facing the rear side 7 and facing the pressure chamber 52, the return outlet 113 is formed in a side surface 871 of the pump body 87 radially facing outwards (with respect to a central axis 12 of the hydraulic cylinder 5 corresponding to a central axis of the pump body 87), and the control opening 116 is also formed in the side surface 871 of the pump body 87 (Figure 5).

[0099] According to an embodiment, the return valve 11 is manually actuatable to perform a manual return of the hydraulic piston 6 to the stroke start position. The control member 117 comprises a manual button extending from the outside of the cylinder body 51 into the pump body 87 and into engagement (for example a cam or wedge engagement) with the return shutter 115 (Figure 5). The control member 117 forms a resiliently biased abutment portion (by means of the spring 118) against a stop surface (deactivated button position) formed directly in the cylinder body 51 and an outer end portion 119 (button surface) protruding outwardly from the cylinder body 51 into an internal space of the tank 3 delimited by a tank wall 31 which is at least locally flexible at the outer end 119, to allow manual pressing or rotation of the control member 117 through the flexible tank wall 31.

[0100] This configuration reduces the number of sealing interfaces and simplifies the structure and cost of the manual return button.

[0101] According to an embodiment (Figure 6), the pump module 80 comprises a detectionchannel 13 formed in the pump body 87 between a first detection opening 130 (Figure 9) in communication with the pressure chamber 52 and a second detection opening 131 in communication with a detection seat 132 formed in the cylinder body 51, wherein the detection seat 132 accommodates a pressure sensor 133 or a closing cap 134 which prevents communication of the detection channel 13 with an external environment.

[0102] The good accessibility to all external sides of the pump body 87 simplifies the mechanical machining to make the detection channel 130, limiting the machining operations of the cylinder body 51 to the realization of the detection seat 132 only, as compared with a complete realization of the detection channel 13 in the cylinder body.

[0103] Furthermore, the positioning of the detection channel 13 in the pump module 80 inserted into the hydraulic cylinder 5 makes better use of the spaces available inside the actuation device 1.

[0104] According to an embodiment, the first detection opening 130 is formed in the rear surface 870 of the pump body 87 facing the rear side 7 and facing the pressure chamber 52 and the second detection opening 131 is formed in the front surface 872 of the pump body 87 (Figures 6, 8B, 8D). Advantageously, to better exploit the available spaces in the pump body 87, the detection channel 13 is formed by two parallel holes, transversely offset but communicating (Figure 6).

[0105] According to an embodiment, the detection channel 13 also acts as a purge access of the pressure chamber 52, and for this reason is in communication with an access channel 135 formed in the cylinder body 51, distinct from (but in communication with) the detection seat 132, and closable by means of an access screw 136 and openable in communication with an external environment.

[0106] According to an embodiment, the same access screw 136 may serve to secure the position of the pump module 80 in the front bottom region 54 of the hydraulic cylinder 5.

[0107] The access screw 136 extends from the outside of the hydraulic cylinder 5 into the second detection opening 131, for example through an axial hole in a front wall of the cylinder body 51 (Figure 6). A sealing gasket may be placed between the access screw 136 and the cylinder body 51. The access screw 136 may form a communication channel 137 which ensures, even with the access screw 136 screwed in, a fluid communication between the detection channel 13 and the detection seat 132 (Figure 6).

[0108] According to an embodiment, the pump module 80 comprises a filling channel 14, usable for filling and / or purging the tank 3, and formed in the pump body 87 between a filling outlet 140 in communication with the tank 3 and a filling inlet 141 closable by means of a closing screw 142 and openable in communication with an external environment.

[0109] According to an embodiment, the same closing screw 142 may serve to secure the position of the pump module 80 in the front bottom region 54 of the hydraulic cylinder 5.

[0110] Also in this case, the good accessibility to all external sides of the pump body 87 simplifies the mechanical machining to make the filling channel 14, reducing the machining operations of the cylinder body 51 , as compared with a realization of the entire filling channel 14 in the cylinder body 51 or in the outer wall of the tank 3.

[0111] Furthermore, the positioning of the filling channel 14 in the pump module 80 inserted into the hydraulic cylinder 5 makes better use of the spaces available inside the actuation device 1.

[0112] According to an embodiment, the filling outlet 140 is formed in the side surface 871 of the pump body 87 radially facing outwards, and the filling inlet 141 is formed in the front surface 872 of the pump body 87 facing the front bottom 54 of the hydraulic cylinder 5 (Figures 7, 8D).

[0113] The closing screw 142 extends from the outside of the hydraulic cylinder 5 into the filling inlet 141, for example through an axial hole in a front wall of the cylinder body 51 (Figure 7). A sealing gasket may be placed between the closing screw 142 and the cylinder body 51.

[0114] According to an embodiment, the actuation device 1 comprises an annular gasket 873 extending all around the pump body 87 in the use position (for example in an annular gasket seat formed in the hydraulic cylinder 5 or in the pump body 87) and which hermetically separates the pressure chamber 52 from an annular space 55, delimited by the cylinder body 51 and the side surface 871 of the pump body 87, and in communication with the tank 3.

[0115] To overcome the known difficulties in completely purging the cavities of a complex hydrodynamic system, in particular the difficulties in eliminating air bubbles through the filling opening, according to an embodiment, the actuation device 1 further comprises a purging channel 15, on the rear side of the hydraulic cylinder 5, for example formed in the cylinder body 51 itself or in a rear delimiting wall 151 of (the rear chamber 53 of) the hydraulic cylinder 5, for example a purging channel 15 extending radially to the central axis 12, and closed by means of a purging cap 152 (Figure 10).

[0116] This allows better maintenance, air evacuation and filling of the entire hydraulic system.

[0117] According to an embodiment, the rear delimiting wall 151 may be formed by a fork body of the working head 16 of the portable tool 2.

[0118] The tank 3 comprises a rear tank portion 32 formed externally around the cylinder 5 and around the communication holes 56.

[0119] According to an embodiment (Figures 1, 11), the tank 3 is formed around the cylinder body 51 and comprises a tank wall 31 having a rigid region whose outer surface directly forms a manual handle 33 of the portable tool 2, and whose inner surface directlydelimits, together with an outer surface of the cylinder body 51 , an internal volume of the tank 3.

[0120] According to an embodiment (Figure 2), the portable tool 2 comprises a reduction mechanism 19 connected between the electric motor 9 and the hydraulic pump 8. The reduction mechanism 19 comprises a reducer housing 191 made of plastic:

[0121] - connected to the motor 9 by means of a first connection plate 192 made of steel, screwed to the motor 9 by means of connection screws 193, and

[0122] - connected to the cylinder body 51 by means of a second connection plate 194 made of steel, screwed to the cylinder body 51 (preferably directly, by means of a thread formed on the connection plate 194), wherein the first connection plate 192 and the second connection plate 194 are connected to each other by means of threaded connection tie-rods 195, extending through tie-rod channels 197 formed in the reducer housing 191.

[0123] This configuration is particularly advantageous for achieving reduced radial dimensions, such as to allow the formation of a conveniently slim manual handle around the actuation device 1. In fact, space conflicts between a ring gear 196 of the epicyclic reduction gear mechanism 19 and the connection screws 193 are avoided (Figure 2).

[0124] Description of the maximum pressure valve 17

[0125] According to an aspect of the invention (Figures 10-14), the actuation device 1 comprises a maximum pressure valve 17 positioned in a release duct 171 of the hydraulic fluid from the pressure chamber 52 into the tank 3,

[0126] wherein:

[0127] - the release duct 171 comprises a release inlet 172 formed in the hydraulic piston 6 and facing the pressure chamber 52, and a release outlet 173 in communication with the tank 3, and

[0128] - the maximum pressure valve 17 comprises a valve seat 174 formed in the release duct 171 in the hydraulic piston 6 and a release shutter 175 extending into the hydraulic piston 6.

[0129] The realization (of part) of the release duct 171 and the positioning of the maximum pressure valve 17 in the hydraulic piston 6 allow better use of the spaces available inside the actuation device 1.

[0130] Furthermore, the good accessibility to all external sides of the hydraulic piston 6, before its insertion into the hydraulic cylinder 5, simplifies the mechanical machining to make the release inlet 172, the release duct 171 , the valve seat 174 and the accommodation space for the release shutter 175, as compared with their realization in the cylinder body 51.

[0131] According to an embodiment (Figures 11, 13), the hydraulic piston 6 is formed by a multi-component piston unit 61 with:

[0132] - a front piston body 62 adjacent to the pressure chamber 52 and forming the releaseinlet 172 and the valve seat 174 of the maximum pressure valve 17,

[0133] - a rear body 63 arranged on the rear side 7 (opposite the pressure chamber 52) and biased in abutment against the front piston body 62 by a return spring 64 which biases the entire piston unit 61, or generally the hydraulic piston 6, (towards a front side 7' of the hydraulic cylinder 5) into a stroke start position,

[0134] wherein the front piston body 62 and the rear body 63 together delimit part of the release duct 171 and a valve chamber 176 in which the release shutter 175 is positioned.

[0135] This configuration improves accessibility to the surfaces requiring machining and simplifies the realization of the release duct 171, the valve seat 174 and the valve chamber 176.

[0136] According to an embodiment, not required to keep the rear body 63 joined to the front valve body 62 during operation of the actuation device 1 , but advantageous for facilitating the assembly of the parts, the rear body 63 may be constrained to the front valve body 62 by means of an elastic clip 65, for example a Seeger ring (Figures 13, 14).

[0137] The rear body 63 may also integrally form the transmission member 10.

[0138] According to an embodiment, the release shutter 175 is biased into the valve seat 174 by a valve spring 177 abutting between the rear body 63 and the release shutter 175. The elastic force of the valve spring 177 determines the maximum pressure value at which the maximum pressure valve 17 opens the release duct 171. The elastic force applied by the return spring 64 is greater than the force applied by the valve spring 177, so that the valve spring 177 cannot move the rear body 63 away from the front piston body 62 (Figure 11).

[0139] According to an embodiment (Figures 13, 14), the maximum pressure valve 17 comprises a rebound plate 178 connected to the release shutter 175 and positioned in the release duct 171 in the hydraulic piston 6 or in the piston unit 61 so as to overcome or at least balance (thanks to the flow of hydraulic fluid pushing against the rebound plate 178), with the maximum pressure valve 17 open, the elastic force of the valve spring 177 to keep the maximum pressure valve 17 open (“floating”), possibly until the hydraulic piston 6 returns to the stroke start position. Figures 10 and 11 illustrate the two situations of closed valve (Figure 10) and open, floating valve (Figure 11).

[0140] This configuration is easy to manufacture thanks to the positioning of the maximum pressure valve 17 in the hydraulic piston 6 or in the piston unit 61. In contrast, placing the rebound plate 178 (which has significant transverse dimensions) in the cylinder body 51 would be very costly in terms of machining, bulk, and material and weight of the cylinder body 51.

[0141] According to an embodiment, again with the aim of simplifying machining and assembly, at least part of the rebound plate 178, for example a peripheral annular portion 179, is made as a separate part from the release shutter 175, inserted onto a rear stem 1710of the release shutter 175 and retained in abutment against the release shutter 175 by the valve spring 177 (Figures 13, 14).

[0142] According to an embodiment, the elastic force of the valve spring 177 is adjustable by adjusting the position of a reaction body 1711 against which the valve spring 177 abuts. The reaction body 1711 and an adjustment screw 1712 in contact with (or formed as one piece with) the reaction body 1711, are positioned inside the piston unit 61, preferably inside the (valve chamber 176 of the) rear body 63, and adjustable by means of a screwdriver or Allen key from the outside of the piston unit 61. A locking ring nut 1713 may also be associated with the adjustment screw 1712 to secure the adjustment screw relative to the rear body 63, with the purpose of preserving the setting of the elastic force of the valve spring 177.

[0143] According to an embodiment, the reaction body 1711 forms a guide hole 1714 in which the rear stem 1710 of the shutter extends in a slidable manner (to ensure correct positioning and sliding of the release shutter 175). The reaction body 1711 (equipped with an O-ring) forms a hermetic sealing cap of the (valve chamber 176 and of the part of the release duct 171 of the) rear body 63, i.e., of the entire piston unit 61 with respect to an environment external to the hydraulic actuator 1. To avoid unwanted hydraulic resistance against the free sliding of the release shutter 175 relative to the reaction body 1711, the rear stem 1710 forms a vent channel 1715 (formed by a longitudinal hole and a communicating transverse hole) which puts the interior of the guide hole 1714 in communication with the release duct 171.

[0144] The release duct 171 comprises a plurality of flow grooves 1716 formed in an internal cylindrical surface 1717 (Figure 12B) of the front piston body 62 which surrounds the rebound plate 178, and / or a plurality of axial flow holes 1718 formed in the rear body 63 (Figures 13, 14), to allow, with the maximum pressure valve 17 open, a release flow from the release inlet 172 into the rear chamber 53 of the hydraulic cylinder 5.

[0145] A front surface 68 of the hydraulic piston 6 forms a plurality of front radial grooves 69 (Figure 12A) which ensure flow communication between the pressure chamber 52 and the release inlet 172 when the piston 6 is approach ing / towards the stroke start position.

[0146] According to an embodiment, the front piston body 62 (which, thanks to the multicomponent configuration of the piston unit 61, is relatively small) is made of steel, with the advantage of being able to form the valve seat directly in steel without needing to make a dedicated steel insert, but also without having to make the entire piston unit 61 in steel. Indeed, the rear body 63 may be made of a less resistant and lighter metal / material, for example aluminium alloy.

[0147] The rear chamber 53 of the hydraulic cylinder 5 is in permanent communication with the tank 3, for example by means of a plurality of radial communication holes 56, preferably formed in an internal circumferential groove 57 of the hydraulic cylinder 5, at an end-of-strokeabutment 58 for an end-of-stroke support of the hydraulic piston 6 (Figure 3).

[0148] A rear surface 66 of the hydraulic piston 6 forms a plurality of rear radial grooves 67 (Figure 12B) which ensure flow communication between the rear chamber 53 and the communication holes 56 even when the piston 6 is in the end-of-stroke position.

[0149] Description of the working head 16

[0150] According to an aspect of the invention, referring to the generic portable tool 2 or to the portable tool according to one of the various embodiments described, the working head 16 comprises:

[0151] - a fork body 161 made of metal, for example aluminium alloy, which supports the jaws 18,

[0152] - a roller holder 162 connected to the transmission member 10 and supporting one or two rollers 163 in (rolling) contact with (at least one jaw 18 of) the pair of jaws 18,

[0153] - a guide surface system 164, 164' which at least partially surrounds the rollers 163, prevents the rollers 163 from falling out of the working head 16 and guides the rollers 163 along a drive stroke 165 (Figures 16, 17),

[0154] - a housing 166 made of polymer material connected externally around the fork body 161 and forming the guide surface system 164, 164' (Figures 1, 2, 15-18).

[0155] This configuration achieves a saving of metallic material, a reduction in weight and in metal machining operations at the cost of a production phase of polymer material injection moulding (plastic, e.g. polyethylene, polyamide).

[0156] According to an embodiment, the housing 166 comprises a front annular portion 166' extending all around the fork body 161 and two opposing shell portions 166" extending from the front portion 166' in a longitudinal direction 1610 of the working head 16, for example in the direction of the drive stroke 165, and delimiting between them two slits or movement spaces 1611 for the movement of the jaws 18.

[0157] The shell portions 166" externally cover two arms 1612 of the fork body 161 and each form two opposing edge portions 1613, parallel and extended beyond the respective fork arm 1612, wherein each edge portion 1613 forms two respective said guide surfaces 164, 164' in two guide planes orthogonal to one another and preferably parallel to the longitudinal direction 1610 of the working head 16 or to the drive stroke 165 (Figures 16, 17).

[0158] According to an embodiment, the jaws 18 are replaceably connected to the fork body 161 , for example by means of a pin 167 insertable into and extractable from the fork body 161 , and releasable, lockable with respect to the fork body 161 , for example by means of a locking lever 168 (Figure 18). Advantageously, an insertion detector 169 for detecting the correct connection of the jaws 18 to the fork body 161, for example a microswitch, is accommodated in the housing 166.

[0159] This avoids the need to create a seat for the insertion detector 169 in the metallicmaterial of the fork body 161 and allows for its precise and economical manufacturing by means of injection moulding.Numerical referencesactuating device 1portable tool 2tank 3tank wall 31rear tank portion 32manual grip 33hydraulic actuator 4hydraulic cylinder 5cylinder body 51pressure chamber 52rear chamber 53front bottom region 54annular space 55communication holes 56inner groove 57end-of-stroke abutment 58hydraulic piston 6piston assembly 61front piston body 62rear body 63return spring 64elastic clip 65rear surface 66rear radial grooves 67front surface 68front radial grooves 69rear side 7front side 7’hydraulic pump 8pump module 80pump cylinder 81pumping piston 82suction check valve 83suction passage 84 delivery check valve 85 delivery passage 86pump body 87rear surface 870lateral surface 871front surface 872annular seal 873annular space 874first valve seat 88second valve seat 89 access opening 810 electric motor 9 transmission member 10 return valve 11return channel 111return inlet 112return outlet 113valve seat 114return shutter 115control opening 116 control member 117spring 118outer end 119central axis 12detection channel 13first detection opening 130 second detection opening 131 detection seat 132pressure sensor 133 sealing plug 134access channel 135access screw 136 communication channel 137 filling channel 14filling outlet 140filling inlet 141closing screw 142bleeding channel 15rear delimiting wall 151 bleeding plug 152working head 16fork body 161roller holder 162rollers 163guide surfaces 164, 164’ actuating stroke 165casing 166front portion 166’shell portions 166”pin 167locking lever 168insertion detector 169 longitudinal direction 1610 movement slots 1611fork arms 1612edge portions 1613 overpressure valve 17 discharge duct 171 discharge inlet 172 discharge outlet 173valve seat 174discharge shutter 175valve chamber 176valve spring 177rebound disc 178 peripheral annular portion 179 rear stem of shutter 1710 abutment body 1711 adjustment screw 1712 locking ring nut 1713guide hole 1714vent channel 1715flow grooves 1716inner cylindrical surface 1717 axial flow holes 1718jaws 18reducer 19reducer housing 191first connection plate 192 first connection screws 193 second connection plate 194 connection tie rods 195 ring gear 196tie rod channel 197

Claims

CLAIMS1. An actuation device (1) for a portable tool (2), comprising:a hydraulic fluid tank (3),a hydraulic actuator (4) having a hydraulic cylinder (5) made of a metal cylinder body (51), a hydraulic piston (6) accommodated in the hydraulic cylinder (5) in a guided manner and dividing the hydraulic cylinder (5) into a pressure chamber (52) and a rear chamber (53) on a rear side (7) of the hydraulic cylinder (5),a hydraulic pump (8) actuatable by an electric motor (9) and having a pump cylinder (81), a pumping piston (82) guided into the pump cylinder (81), a non-return suction valve (83) in a suction passage (84) for the hydraulic fluid from the tank (3) into the pump cylinder (81), a non-return delivery valve (85) in a delivery passage (86) for the hydraulic fluid from the pump cylinder (81) into the pressure chamber (52) to actuate the hydraulic actuator (4),a transmission member (10) extending from the hydraulic piston (6) to transmit a movement of the hydraulic piston (6) to a working head (16) of the portable tool (2),a pump module (80) comprising:- a pump body (87) forming the pump cylinder (81), a first valve seat (88) and a second valve seat (89),- the non-return suction valve (83) in the first valve seat (88),- the non-return delivery valve (85) in the second valve seat (89),wherein the pump module (80) is inserted into the hydraulic cylinder (5) from the rear side (7) in a front bottom region (54) of the hydraulic cylinder (5), opposite to the rear side (7), wherein the pump module (80) delimits, together with the hydraulic piston (5) and the cylinder body (51), said pressure chamber (52).

2. An actuation device (1) according to claim 1 , wherein:- the second valve seat (89) and / or the delivery passage (86) are formed in a rear surface (870) of the pump body (87) facing the rear side (7) and facing the pressure chamber (52), - the first valve seat (88) and / or the suction passage (84) are formed in a side surface (871) of the pump body (87) radially facing outwards with respect to a central axis (12) of the hydraulic cylinder (5),- the pumping piston (82) extends from the outside of the hydraulic cylinder (5) into the pump cylinder (81), through an axial hole in a front wall of the cylinder body (51) and through an access opening (810) formed in a front surface (872) of the pump body (87) facing the front bottom (54).

3. An actuation device (1) according to claim 1 or 2, wherein the pump module (80) comprises:- a return channel (111) formed in the pump body (87) with a return inlet (112) facing the pressure chamber (52) and a return outlet (113) in communication with the tank (3), and - a return valve (11) with a valve seat (114) formed in the return channel (111) and a return shutter (115) accommodated in the pump body (87) and extending into the return channel (111),- a control opening (116) formed in the pump body (87) for accessing a control member (117) from the outside of the pump body (87) up to the engagement with the return shutter (115), said return valve (11) allows performing a voluntary return of the hydraulic piston (6) to a stroke start position thereof.

4. An actuation device (1) according to claim 3, wherein the return inlet (112) is formed in a rear surface (870) of the pump body (87) facing the rear side (7) and facing the pressure chamber (52), the return outlet (113) is formed in a side surface (871) of the pump body (87) radially facing outwards with respect to a central axis (12) of the hydraulic cylinder (5), and the control opening (116) is formed in the side surface (871 ).

5. An actuation device (1) according to claim 3 or 4, wherein the return valve (11) is manually actuatable for manually returning the hydraulic piston (6) to the stroke start position.

6. An actuation device (1) according to claim 3, 4 or 5, wherein the control member (117) comprises an outer end portion (119) protruding outwards from the cylinder body (51) into an inner space of the tank (3) delimited by a tank wall (31) which is at least locally flexible at the outer end (119), to allow manipulating the control member (117) through the flexible tank wall (31).

7. An actuation device (1) according to any one of the preceding claims, wherein the pump module (80) comprises a detection channel (13) formed in the pump body (80) between a first detection opening (130) in communication with the pressure chamber (52) and a second detection opening (131) in communication with a detection seat (132) formed in the cylinder body (51), wherein the detection seat (132) accommodates a pressure sensor (133) or a closing cap (134) which prevents communication of the detection channel (13) with an external environment.

8. An actuation device (1) according to claim 7, wherein the first detection opening (130) is formed in the rear surface (870) of the pump body (87) facing the rear side (7) and facing the pressure chamber (52), and the second detection opening (131) is formed in the front surface (872) of the pump body (87), and / orwherein the detection channel (13) is formed by two parallel holes, transversely offset, but communicating.

9. An actuation device (1) according to claim 7 or 8, wherein the detection channel (13) also acts as an access for purging the pressure chamber (52) and is in communication with an access channel (135) formed in the cylinder body (51) and closable by means of an access screw (136) and openable in communication with an external environment,wherein the access channel (135) is spaced apart from, but in communication with, the detection seat (132).

10. An actuation device (1) according to claim 9, wherein the access screw (136) extends from the hydraulic cylinder (5) into the second detection opening (131), for securing the position of the pump module (80) in the front bottom region (54) of the hydraulic cylinder (5), wherein the access screw (136) forms a communication channel (137) which ensures, also with the access screw (136) screwed, a fluid communication between the detection channel (13) and the detection seat (132).

11. An actuation device (1) according to any one of the preceding claims, wherein the pump module (80) comprises a filling channel (14), usable for filling and / or purging the tank (3), the filling channel (14) being formed in the pump body (87) between a filling outlet (140) in communication with the tank (3) and a filling inlet (141) closable by means of a closing screw (142) and openable in communication with an external environment.

12. An actuation device (1) according to claim 11, wherein the closing screw (142) secures the position of the pump module (80) in the front bottom region (54) of the hydraulic cylinder (5).

13. An actuation device (1) according to claim 10 or 11, wherein the filling outlet (140) is formed in the side surface (871) of the pump body (87), radially facing outwards, and the filling inlet (141) is formed in the front surface (872) of the pump body (87), facing the front bottom (54) of the hydraulic cylinder (5), andthe closing screw (142) extends from the outside of the hydraulic cylinder (5) into the filling inlet (141), through an axial hole in a front wall of the cylinder body (51).

14. An actuation device (1) according to any one of the preceding claims, comprising an annular gasket (873) extending all about the pump body (87) in the use position, and said annular gasket (873) hermetically separates the pressure chamber (52) from an annularspace (55) delimited by the cylinder body (51) and the side surface (871) of the pump body (87), and in communication with the tank (3).

15. An actuation device (1) according to any one of the preceding claims, comprising a purging channel (15), on the rear side of the hydraulic cylinder (5), closed by means of a purging cap (152).

16. An actuation device (1) according to any one of the preceding claims, wherein:- the cylinder body (51) is made of a lighter material than the material of the pump body (87), and the pump body (87) is made of a mechanically more resistant material than the material of the cylinder body (51), or- the cylinder body (51) is made of aluminum and the pump body (87) is made of steel.

17. An actuation device (1) according to any one of the preceding claims, wherein the tank (3) comprises a rear tank portion (32) formed externally about the cylinder body (51) and about the communication holes (56).

18. An actuation device (1) according to any one of the preceding claims, wherein the tank (3) is formed about the cylinder body (51) and comprises a tank wall (31) having a rigid region, the outer surface of which directly forms a manual handle (33) of the portable tool (2), and the inner surface of which directly delimits, together with an outer surface of the cylinder body (51), an inner volume of the tank (3).

19. An actuation device (1) according to any one of the preceding claims, comprising a reduction mechanism (19) connected between the electric motor (9) and the hydraulic pump (8), wherein the reduction mechanism (19) comprises a reducer housing (191) made of plastic:- connected to the motor (9) by means of a first connection plate (192) made of steel, screwed to the motor (9) by means of connection screws (193), and- connected to the cylinder body (51) by means of a second connection plate (194) made of steel, screwed to the cylinder body (51) by means of screws or directly by means of a thread formed on the connection plate (194),wherein the first connection plate (192) and the second connection plate (194) are connected to each other by means of threaded connection tie-rods (195), extending through tie-rod channels (197) formed in the reducer housing (191).

20. A portable tool (2), comprising an actuation device (1) according to any one of thepreceding claims.

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