Device for Anti-rotational blocking
Patent Information
- Application Number
- PCT/IB2026/052516
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-19
- Filing Date
- 2026-03-16
- Publication Date
- 2026-09-24
Smart Images
Figure IB2026052516_24092026_PF_FP_ABST
Abstract
Description
[0001] DEVICE FOR ANTI-ROTATIONAL BLOCKING
[0002] Technical Field
[0003] The present invention relates to a blocking device, specifically a device intended to block mechanical parts using an anti -rotational system.
[0004] Background Art
[0005] As is well known, industrial production widely employs highly automated systems wherein one or more machines carry out specific machining operations on one object and are provided with specific fastening systems, of the hydraulic or air-operated type, that take hold of the object and block it at the working position.
[0006] Once the process is completed, the aforementioned fastening systems release the object, thus allowing it to be spaced apart from the machine.
[0007] A particular type of fastening systems consists of a bracket that, via a hydraulic or air-operated actuator, is movable both in a revolving manner around an axis of rotation and in a sliding manner along the same axis of rotation.
[0008] The bracket is mounted cantilevered onto the rod of a hydraulic / air-operated actuator partly inserted into a fluid-operated cylinder.
[0009] Between the rod and the cylinder, there are roto-translation means, that is, special constraint means that allow the rod, and therefore the bracket mounted thereon, to rotate and translate.
[0010] Such fastening systems must be capable of exerting very high blocking forces on the object.
[0011] Nevertheless, it sometimes happens that the object is not positioned correctly and precisely and / or that the fastening systems fail to immobilize the object perfectly, thus risking jeopardizing the entire process and damaging the object and / or the fastening systems themselves.
[0012] In particular, in certain processes and / or machining operations, it is necessary to secure a large drum or tank containing fluids / liquids to be mixed, in which the drum or tank is subjected to a precession motion that promotes the mixing of the fluids / liquids; such processes and machining operations are common, e.g., in the dairy and food sector, the chemical industry, the paint industry, and the like.
[0013] It is easy to appreciate, therefore, that the traditional fastening systems must be designed so as to apply and withstand forces directed in multiple spatial directions, that is, not only axial forces parallel to the rod of the hydraulic / air-operated actuator, but also torsional and bending forces that discharge on the bracket and on the rod as a result of the aforementioned precession motion.To this end, it is known to use blocking devices provided with anti -rotational systems, i.e., capable of physically stabilizing the rod and the bracket at the working position. An example of such blocking devices is shown in patent document EP3416781, which provides for the use of prismatic guiding bodies, formed as turrets associated with the exterior of the hydraulic cylinder, which can be prismatically engaged with the bracket during the rod’s displacement toward the working position, thereby blocking the bracket and securing it at that position and preventing any torsional or flexural movements.
[0014] The blocking device of EP3416781 is however also susceptible to improvements. In fact, it is noted that the conditions under which the traditional fastening systems must operate are often very complex; the spaces on board the machines are generally very limited and not all of them usable, since certain areas are subject to the accumulation of dirt, deposits, condensation, rust, and other corrosive agents that could obstruct the prismatic coupling between the bracket and the turrets.
[0015] Furthermore, in many practical applications, it is required, if not necessary, that the blocking systems have very compact external dimensions; in this regard, the turrets positioned outside the hydraulic cylinder can be an obstruction or impediment that hinders the proper operation of the machine.
[0016] Furthermore, precisely because of their compact dimensions, it is always quite complex and difficult to provide for the traditional blocking systems with additional components that improve the performance thereof.
[0017] Description of the Invention
[0018] The main aim of the present invention is to devise a device for anti -rotational blocking which allows for securely blocking an object for the machining thereof, by applying and withstanding forces directed in multiple spatial directions, while simultaneously operating effectively even in environments subject to dirt, scale, condensation, rust, and other corrosive agents.
[0019] Another object of the present invention is to devise a device for anti -rotational blocking with very limited overall dimensions.
[0020] Yet another object of the present invention is to devise a device for anti -rotational blocking that can be manufactured using a simple technique, allowing for adopting adaptation techniques using already known and / or available materials, thereby significantly reducing costs.
[0021] A further object of the present invention is to devise a device for anti -rotational blocking that allows the aforementioned drawbacks of the prior art to be overcomewithin the framework of a simple, rational solution that is also easy and effective to use.
[0022] The aforementioned objects are achieved by the present device for anti -rotational blocking having the characteristics of claim 1.
[0023]
[0024] of the
[0025] Other characteristics and advantages of the present invention will become more apparent from the description of a preferred, but not exclusive, embodiment of a device for anti -rotational blocking, illustrated by way of an indicative, yet non-limiting example, in the attached drawings, in which:
[0026] Figure 1 is an axonometric view of the device according to the invention;
[0027] Figure 2 is an exploded view of the device according to the invention;
[0028] Figure 3 is a cross-sectional view of the device according to the invention in the home configuration;
[0029] Figure 4 is a cross-sectional view, along a different sectional plane, of the device according to the invention in the home configuration;
[0030] Figure 5 is a cross-sectional view, along the sectional plane in Figure 4, of the device according to the invention in an intermediate configuration;
[0031] Figure 6 is a cross-sectional view, along the sectional plane in Figure 4, of the device according to the invention in the working configuration.
[0032] Embodiments of the Invention
[0033] With particular reference to these figures, reference numeral 1 globally denotes a device for anti -rotational blocking.
[0034] The device 1 is particularly intended to block an object O after it has been placed on a working surface L of a machine M.
[0035] The device 1 comprises at least one base body 4 attachable to a machine M, e.g. to its working surface L, to its bedplate, or to any other part thereof.
[0036] The base body 4 is provided with a fluid-operated cylinder 5 containing a pressurized fluid.
[0037] For the purposes of this disclosure, the term “pressurized fluid” refers to any fluid in the liquid state (and therefore ideally incompressible) or in the gaseous state (and therefore compressible) used as a medium for conveying energy into a hydraulic or air-operated circuit; preferably, the pressurized fluid consists of a traditional mineral oil, but alternative embodiments cannot be ruled out, wherein it may be synthetic oil, vegetable oil, water, air, or the like.
[0038] Since the device 1 has several parts in contact with the pressurized fluid, special sealsare provided at various points on the device 1; for sake of representation, these are commonly identified by reference numeral 31.
[0039] The fluid-operated cylinder 5 e.g. comprises:
[0040] a baseplate 6 which is preferably configured to be fastened to the machine M and comprises a central seat 7 facing upward;
[0041] a plate 8 which is preferably associated with the central seat 7.
[0042] Advantageously, the fluid-operated cylinder 5 also comprises a hollow jacket 9, which extends along an axis of development B, is associated on top of the baseplate 6 around the central seat 7, and is provided with an upper opening 11.
[0043] It should be noted that, in the context of this disclosure, terms such as “upper,” “above,” “higher,” and similar expressions, as well as “top,” “below,” “lower,” and similar terms, are used with reference to the specific configuration of the device 1 shown in the figures, wherein the axis of development B is arranged substantially vertically.
[0044] It is easy to appreciate, however, that the device 1 may be attached to the machine M with the axis of development B directed differently, e.g. horizontally or obliquely, depending on the shape and layout of the object O to be blocked.
[0045] The fluid-operated cylinder 5 has an active face 13, i.e., a surface at least partly transverse to the axis of development B and intended to come into contact with the pressurized fluid.
[0046] In the specific embodiment shown in the figures, the active face 13 of the fluid-operated cylinder is defined by a surface of the baseplate 6 and of the plate 8 facing upward.
[0047] Conveniently, the central seat 7 is through-going and passes through the baseplate 6 from opposite sides; in other words, the central seat 7 faces not only upward but also downward.
[0048] Advantageously, the base body 4 also comprises a bottom element 14 that is associated beneath the baseplate 6 around the central seat 7.
[0049] The device 1 also comprises at least one rod 15, which extends along a main axis A and is partly inserted within the fluid-operated cylinder 5 in a sliding manner along the main axis A by the thrust of the pressurized fluid.
[0050] Usefully, the main axis A coincides with the axis of development B.
[0051] The rod 15 comprises at least one inner portion 16 within the fluid-operated cylinder 5 and one outer portion 17 outside the fluid-operated cylinder 5, from which it extends through the upper opening 11.The device 1 also comprises at least one piston 10 associated with the inner portion 16 and having an active face 21 facing the active face 13 of the fluid-operated cylinder. The active face 21 of the piston is a surface that is at least partly transverse to the main axis A and is intended to come into contact with the pressurized fluid.
[0052] In other words, the piston 10 slides to size on the inner walls of the hollow jacket 9 and divides the fluid-operated cylinder 5 into a first chamber 18 and into a second chamber 19, which are opposite each other; the supply of pressurized fluid alternately to the two chambers 18, 19 allows the rod 15 to slide in one direction or in the opposite direction along the main axis A.
[0053] The first chamber 18 is bounded not only by the inner walls of the hollow jacket 9 but also by the active face 13 of the fluid-operated cylinder and by the active face 21 of the piston.
[0054] The pressurized fluid introduced into the first chamber 18 operates on the active face 21 of the piston, thus causing it to displace along the main axis A.
[0055] Similarly, the second chamber 19 is also bounded by the inner walls of the hollow jacket 9 and by specific faces of the fluid-operated cylinder 5 and of the piston 10; the fluid introduced under pressure into the second chamber 19 operates on the piston 10, causing it to be displaced along the main axis A in the opposite direction.
[0056] In the embodiment shown in the figures, the first chamber 18 is located below the piston 10, while the second chamber 19 is located on top of the piston 10.
[0057] Still with reference to the embodiment shown in the figures, it can be seen that the piston 10 and the rod 15 are formed as a single monolithic body piece; in other words, the piston 10 defines a portion of the rod 15 with an enlarged cross-section; different embodiments cannot however be ruled out wherein the piston 10 and the rod 15 consist of separate components assembled together.
[0058] Between the fluid-operated cylinder 5 and the rod 15 there are roto-translation means 20 adapted to divide the motion of the rod 15 into:
[0059] at least a first roto-translation stretch C, wherein the rod 15 slides along the main axis A and rotates around the main axis A; and
[0060] at least a second translation stretch D, wherein the rod 15 slides along the main axis A without rotating.
[0061] Advantageously, the roto-translation means 20 comprise:
[0062] at least one groove 24, 25 formed on at least one of either the rod 15 or the fluid- operated cylinder 5 and having a first substantially helical-shaped portion 24 and a second substantially straight portion 25; andat least one engagement element 26 mounted on the other of either the rod 15 or the fluid-operated cylinder 5 and inserted within the groove 24, 25 in a sliding manner.
[0063] The sliding of the engagement element 26 along the first portion 24 causes the motion of the rod 15 along the first stretch C and the sliding of the engagement element 26 along the second portion 25 causes the motion of the rod 15 along the second stretch D.
[0064] In the specific embodiment of the device 1 shown in the figures, the groove 24, 25 is advantageously cut on the outer surface of the rod 15, while the engagement element 26 is mounted on the fluid-operated cylinder 5; alternative embodiments cannot however be ruled out wherein, conversely, the groove 24, 25 is cut on the fluid-operated cylinder 5 and the engagement element 26 is mounted on the rod 15.
[0065] More specifically, the groove 24, 25 is advantageously cut on an engagement portion 22 of the rod 15, which extends along the main axis A and is located below the piston 10.
[0066] In even greater detail, in the specific embodiment of the device 1 shown in the figures, the roto-translation means 20 comprise two grooves 24, 25, cut on the outer surfaces of the engagement portion 22, and two engagement elements 26, mounted on the base body 4, so as to ensure greater stability and precision during the actuation of the rod 15.
[0067] The high precision in the movement of the rod 15 is also due to the fact that the roto-translation means 20 comprise elastic compensating means 27 adapted to push the engagement elements 26 within the grooves 24, 25.
[0068] In actual facts, the elastic compensating means 27 ensure that the sliding of the engagement elements 26 within the corresponding grooves 24, 25 always occurs with the utmost precision, even when the contacting surfaces begin to wear; in other words, the elastic compensating means 27 allow for the compensation of clearance and wear between the grooves 24, 25 and the engagement elements 26.
[0069] The elastic compensating means 27 consist, e.g., of one or more cup springs 28 arranged so as to exert on the engagement elements 26 a direct force necessary for proper contact with the grooves 24, 25.
[0070] Conveniently, the engagement elements 26 are mounted on the plate 8.
[0071] For this purpose, the plate 8 is associable with the baseplate 6 in a removable manner and is provided with:
[0072] at least one passage hole 29, into which the engagement portion 22 is inserted; andat least one housing hole 30 that houses at least one engagement element 26.
[0073] Preferably, there are two housing holes 30, one for each engagement element 26, and they also house the elastic compensating means 27. Different embodiments cannot however be ruled out wherein three or more housing holes 30 are provided.
[0074] In actual facts, the elastic compensating means 27 push the engagement elements toward the passage hole 29, causing them to protrude from the housing holes 30 to engage in the grooves 24, 25 on the engagement portion 22.
[0075] In the embodiment shown in the figures, the passage hole 29 extends vertically while the housing holes 30 extend horizontally.
[0076] Other embodiments cannot however be ruled out, wherein e.g. the passage hole 29 and the housing holes 30 are oriented differently, or wherein the plate 8 is associated with the baseplate 6 in a non-removable manner (e.g., because they are formed as a single monolithic body piece). The device 1 also comprises anti -rotational means 32, which are configured to prismatically guide the rod 15 along the second stretch D and which comprise:
[0077] at least one cavity 33 formed on at least one of either the active face 21 of the piston or the active face 13 of the fluid-operated cylinder; and
[0078] at least one protrusion 34 formed on the other of either the active face 21 of the piston or the active face 13 of the fluid-operated cylinder and insertable within the cavity 33.
[0079] In the specific embodiment shown in the figures, the cavity 33 is formed on the active face 21 of the piston, while the protrusion 34 is formed on the active face 13 of the fluid-operated cylinder and comprises at least one pin associable with the base body 4 in a removable manner, e.g. by screwing.
[0080] Preferably, the protrusion 34 consists of and coincides with the pin; for this reason, in the remainder of this disclosure, both will be designated by reference numeral 34. Conveniently, the pin 34 is configured to fasten itself to the base body 4 and, simultaneously, also fasten the plate 8.
[0081] In fact, the plate 8 comprises at least one through hole 36, while the pin 34 comprises:
[0082] at least one attachment portion 38 insertable through the through hole 36 and attachable to the baseplate 6 in a removable manner; and
[0083] at least one shoulder portion 37 of larger transverse dimensions than the attachment portion 38 and the through hole 36;
[0084] the plate 8 being placed in a sandwich fashion between the baseplate 6 and the shoulder portion 37 to define a stud coupling.It is easy to appreciate how this particular expedient allows for the correct positioning of both the plate 8, the roto-translation means 20 (associated with the plate 8), and the anti -rotational means 32 (represented by the pin 34), thus ensuring their angular phasing and perfect alignment between the cavity 33 and the protrusion 34 during the motion of the rod 15 along the second stretch D.
[0085] In other words, the interaction between the roto-translation means 20 and the anti-rotational means 32 determines the correct prismatic coupling between the rod 15 and the base body 4, ensures the secure and stable fastening of the object O and, at the same time, provides high resistance to stresses, vibrations, bending, and torsional moments that could jeopardize the proper operation of the device 1.
[0086] The alignment and coupling between the cavity 33 and the protrusion 34 is also, though not necessarily, promoted by the fact that the protrusion 34 comprises at least one inclined guiding edge 39 adapted to promote the prismatic coupling to the cavity 33; the inclined guiding edge 39 consists e.g. of a chamfer or a fillet.
[0087] Usefully, the coupling between the cavity 33 and the protrusion 34 is also promoted by the fact of providing a small amount of clearance between the two.
[0088] In particular, the cavity 33 has a cylindrical conformation and a cavity diameter 0c, while the protrusion 34 also has a cylindrical conformation and a protrusion diameter 0s, wherein the cavity diameter 0c is larger than the protrusion diameter 0s by a difference of between 0.1 mm and 0.5 mm, preferably of between 0.15 mm and 0.3 mm, better still equal to 0.2 mm.
[0089] Usefully, in the embodiment shown in the figures, the anti -rotational means 32 comprise a plurality of cavities 33 and of protrusions 34, so as to ensure a greater anti-rotational effect once the pins 34 are inserted into the cavities 33; embodiments cannot, however, be ruled out wherein a single pin 34 may be provided.
[0090] The device 1 also comprises at least one bracket element 40 associated with the outer portion 17 of the rod 15 and configured for blocking the object O.
[0091] The bracket element 40 can, e.g., be fastened to the outer portion 17 by means of a fastening ring nut 44.
[0092] The bracket element 40 is movable between:
[0093] a home position, wherein the bracket element 40 is spaced apart from the base body 4;
[0094] an intermediate position, wherein the bracket element 40 is rotated and moved close to the base body 4 than the home configuration as a result of the motion of the rod 15 along the first stretch C; anda working position, wherein, with respect to the intermediate position, the bracket element 40 is further moved close to the base body 4 as a result of the motion of the rod 15 along the second stretch D.
[0095] The device 1 comprises at least one control assembly 41 adapted to control the attainment of the working position and of the home position by the bracket element 40. The control assembly 41 comprises:
[0096] at least a first sensor 42, associated with the base body 4 and configured to detect the proximity of a sensing portion 45 of the rod 15 and the attainment of the working position; and
[0097] at least a second sensor 43 associated with the base body 4 at a position other than the first sensor 42 and configured to detect the proximity of the sensing portion 45 and the attainment of the home position.
[0098] Usefully, the sensing portion 45 is defined by a terminal stretch of the rod 15 associated below the engagement portion 22.
[0099] Advantageously, the first sensor 42 and the second sensor 43 are of the electronic type and consist e.g. of proximity sensors, magnetic sensors, optical sensors or the like. The sensors 42 and 43 are connected to a control system, not shown in the figures, configured to command the device 1, specifically the delivery and backflow of pressurized fluid to displace the rod 15 along the first stretch C and the second stretch D and the bracket element 40 between the home position and the working position. Advantageously, the control assembly 41 also comprises adjusting means 46 for adjusting the position of the second sensor 43.
[0100] The adjusting means 46 comprise, e.g., a supporting holder 47 that holds the second sensor 43 and is associated with the base body 4 (preferably with the bottom element 14) in a movable manner along the main axis A; by raising or lowering the supporting holder 47, it is possible to move the second sensor 43 close to or away from the first sensor 42 and set the working position sensing point according to the height of the object O.
[0101] The adjusting means 46 are used to set the distance of the bracket element 40 from the working surface L at the working position, adapting it to the height of the object O, to prevent operations that could potentially endanger the soundness of the object O and of the device 1 from being carried out.
[0102] The operation of the device 1 is as follows.
[0103] At the home position, the bracket element 40 is located so as to leave a clear space on top of the working surface to allow for the placement of the object O.As a result of the supply of the pressurized fluid internally to the fluid-operated cylinder 5, the rod 15 slides within the base body 4 along the first stretch C and the bracket element 40 is displaced from the home position to the intermediate position. At the intermediate position, the bracket element 40 is rotated with respect to the home position and is located at least partly on top of the object O.
[0104] The extreme precision of operation of the roto-translation means 20 which, thanks to the elastic compensating means 27, are able to offset the wear in the grooves 24, 25 and in the engagement elements 26, allows the cavities 33 on the active face 21 of the piston to be perfectly aligned with the pins 34 coming out of the plate 8, thereby preventing subsequent jamming issues.
[0105] Once the intermediate position is achieved, the supply of pressurized fluid within the fluid-operated cylinder 5 continues and the rod 15 slides within the base body 4 along the second stretch D.
[0106] During the motion of the rod 15 along the second stretch D, the bracket element 40 is displaced from the intermediate position to the working position until the bracket element 40 rests on the object O, blocking it against the working surface L.
[0107] It has in practice been ascertained that the described invention achieves the intended objects.
[0108] In this regard, it should be noted that the specific expedient of providing a prismatic coupling between the cavities and the pins located inside the fluid-operated cylinder allows the object to be securely blocked in position, thus withstanding the influence of even very high external forces and stresses.
[0109] In the working position, in fact, the prismatic coupling between the cavities and the pins blocks any form of rotation, bending, or twisting of the rod, thus creating a solid and robust anti -rotational system that safeguards the soundness of the roto-translation means.
[0110] This ensures the proper long-term operation of the device and, in particular, that of the roto-translation means; this aspect is very important given that, in the event of damage to the roto-translation means, the stability of the bracket element, the precision with which it is moved, and the blocking of the object would be jeopardized.
[0111] It should also be noted that the present invention can be conveniently obtained from already existing blocking devices as a result of targeted and cost-effective modifications, e.g. by cutting the cavities into an already existing rod and inserting pins into an already existing base body; in other words, the device according to the invention is designed to carry out retrofit operations (i.e., updating and modernization),with clear advantages in terms of utilizing the inventory resources.
Claims
CLAIMS1) Device (1) for anti -rotational blocking, comprising:at least one base body (4) attachable to a machine (M) and provided with a fluid- operated cylinder (5) containing a pressurized fluid;at least one rod (15) extending along a main axis (A) and partly inserted within said fluid-operated cylinder (5) arranged in a sliding manner along said main axis (A) by thrust of said pressurized fluid, said rod (15) comprising at least one inner portion (16) within said fluid-operated cylinder (5) and an outer portion (17) outside said fluid-operated cylinder (5);at least one piston (10) associated with said inner portion (16) and having an active face (21) facing an active face (13) of said fluid-operated cylinder (5); at least one bracket element (40) associated with said outer portion (17) configured for blocking an object (O);roto-translation means (20) placed between said fluid-operated cylinder (5) and said rod (15) and adapted to divide the motion of said rod (15) into:at least a first roto-translation stretch (C), wherein said rod (15) slides along said main axis (A) and rotates around said main axis (A); andat least a second translation stretch (D), wherein said rod (15) slides along said main axis (A) without rotating;anti -rotational means (32) configured to prismatically guide said rod (15) along said second stretch (D);characterized by the fact that said anti -rotational means (32) comprise:at least one cavity (33) formed on at least one of either said active face (21) of the piston and said active face (13) of the fluid-operated cylinder; andat least one protrusion (34) formed on the other of either said active face (21) of the piston and said active face (13) of the fluid-operated cylinder and insertable within said cavity (33).2) Device (1) according to claim 1, characterized by the fact that said cavity (33) is formed on said active face (21) of the piston and said protrusion (34) is formed on said active face (13) of the fluid-operated cylinder and comprises at least one pin (34) associable with said base body (4) in a removable manner.3) Device (1) according to one or more of the preceding claims, characterized by the fact that said roto-translation means (20) comprise:at least one groove (24, 25) formed on at least one of either said rod (15) and said fluid-operated cylinder (5) and having a first substantially helical-shaped portion(24) and a second substantially straight portion (25); andat least one engagement element (26) mounted on the other of either said rod (15) and said fluid-operated cylinder (5) and inserted within said groove (24, 25) in a sliding manner;the sliding of said engagement element (26) along said first portion (24) causing the motion of said rod (15) along said first stretch (C) and the sliding of said engagement element (26) along said second portion (25) thus causing the motion of said rod (15) along said second stretch (D).4) Device (1) according to one or more of the preceding claims, characterized by the fact that said roto-translation means (20) comprise elastic compensating means (27) adapted to push said engagement element (26) within said groove (24, 25).5) Device (1) according to one or more of the preceding claims, characterized by the fact that said fluid-operated cylinder (5) comprises:at least one baseplate (6); andat least one plate (8) associable with said baseplate (6) in a removable manner and provided with at least one housing hole (30) of said engagement element (26) and with said elastic compensating means (27).6) Device (1) according to one or more of the preceding claims, characterized by the fact that:said plate (8) comprises at least one through hole;said pin (34) comprises at least one attachment portion (38) insertable through said through hole (36) and attachable to said baseplate (6) in a removable manner; and said pin (34) comprises at least one shoulder portion (37) of larger transverse dimensions than said attachment portion (38) and said through hole;said plate (8) being placed in a sandwich fashion between said baseplate and said shoulder portion (37) to define a stud coupling.7) Device (1) according to one or more of the preceding claims, characterized by the fact that said protrusion (34) comprises at least one inclined guiding edge (39) adapted to promote the prismatic coupling to said cavity (33).8) Device (1) according to one or more of the preceding claims, characterized by the fact that:said cavity (33) has a cylindrical conformation and a cavity diameter (0c); said protrusion (34) has a cylindrical conformation and a protrusion diameter (0s); wherein said cavity diameter (0c) is larger than said protrusion diameter (0s) by a difference of between 0.1 mm and 0.4 mm.9) Device (1) according to one or more of the preceding claims, characterized by the fact that said bracket element (40) is movable between:a home position, wherein said bracket element (40) is spaced apart from said base body (4);an intermediate position, wherein said bracket element (40) is rotated and moved close to said base body (4) than said home position as a result of the motion of said rod (15) along said first stretch (C);a working position, wherein said bracket element (40) is moved close to said base body (4) as a result of the motion of said rod (15) along said second stretch (D) for blocking said object (O);wherein said device (1) comprises at least one control assembly (41) for the attainment of said working position and of said home position, said control assembly (41) comprising:at least a first sensor (42) associated with said base body (4) and configured to detect the proximity of a sensing portion (45) of said rod (15) and the attainment of said working position; andat least a second sensor (43) associated with said base body (4) at a position other than said first sensor (42) and configured to detect the proximity of said sensing portion (45) and the attainment of said home position.10) Device (1) according to one or more of the preceding claims, characterized by the fact that it comprises adjusting means (46) for adjusting the position of said second sensor (43) with respect to said base body (4).