MXPA99003887A - Fluid-operated tool - Google Patents

Abstract

A fluid-operated tool for tightening and loosening of threaded connectors has a turnable engaging unit for engaging a threaded connector so as to turn the threaded connector and to tighten and loosen the threaded connector;and driving unit connected with the engaging unit and acting on the engaging unit so as to turn the engaging unit, the driving unit including two fluid-operated driving elements connected to the engaging unit and operated so that during an initial stage of tightening or a final stage of loosening of a threaded connector one of the fluid-operated driving elements is actuated and drives the engaging unit, while during a final stage of tightening or an initial stage of loosening of a threaded connector the other of the fluid-operated driving elements is operated.

Description

HERRA LIES OPERATED BY FLUID BACKGROUND OF THE I NVE NTION The present invention relates to fluid operated tools, such as, for example, hydraulic wrenches and the like. Fluid-operated tools of this type are known in the art. In a known fluid operated tool the coupling means engage a threaded connector to be adjusted or loosened and rotate the threaded connector accordingly, while the driving means is connected to the coupling means to apply the driving force and to rotate the coupling means correspondingly. In known fluid-operated media, the drive means usually includes a fluid-operated piston-cylinder unit. It is well known that during the adjustment of a threaded connector it is necessary first to rotate the threaded connector or to move it downwards on an object on a long stroke, and in a final stage to apply a greater torque on a short stroke to provide the same setting. During the loosening of the threaded connector the situation is reversed, in particular first it is necessary to apply a substantial torque to loosen a threaded connector and then move the threaded connector out of the object over a long stroke. In the known fluid operated tool the adjustment and housing of the threaded connector executed with the same fluid operated drive means is carried out with the same speed through both stages of the process. However, as explained above, the first stage of the adjustment does not require a large torque although it requires a longer stroke related to a longer time, while the additional stage of the adjustment requires a greater torque and a less stroke. Usually, the tools are designed to provide the adjustment of low and high torque, and therefore the stages of travel down and out are very slow and take a long time.

BRIEF DESCRIPTION OF THE INVENTION Accordingly, it is an object of the present invention to provide a fluid operated tool that avoids the disadvantages of the prior art. In complying with these and other objects it will become apparent in the following, a feature of the present invention which resides, said in a few words, in a fluid operated tool for adjusting and loosening the threaded connectors, comprising coupling means which can rotate to attach a threaded connector to rotate the threaded connector and to tighten and loosen the connector - * "- threaded, and drive means connected to the coupling means and acting on the coupling means for rotating the coupling means, the driving means including two fluid-operated driving elements connected to the coupling means and operated from so that during an initial stage of adjustment or a final stage of loosening of a threaded connector one of the fluid-operated driving elements is driven and drives the coupling means, while during a final stage of adjustment or a final stage of loosening of a threaded connector the other fluid operated drive element is operated.When a fluid operated tool is designed in accordance with the present invention, then during the initial step of adjusting a threaded connector (downward displacement), one of the elements Fluid-operated impellers is driven to perform a faster stroke with a lower torque, while during a final stage of the adjustment of the threaded connector of the second fluid operated drive member is also driven to provide a greater torque with a smaller stroke. During the loosening of a threaded connector, the situation is the opposite and the operation of the fluid operated tool is reversed. During the initial stage of loosening a threaded connector, the other fluid-operated impeller or both fluid-operated impellers are activated to apply a greater torque over a smaller stroke, and then during the final stage of the loosening of the threaded connector (outward displacement), only one drive element operated Fluid is activated to provide a lower torque with a faster stroke. The novel features that are considered representative for the present invention are set forth in particular in the appended claims. However, the invention itself, both in its construction and in its method of operation, together with the objects and additional advantages thereof, will be better understood from the following description of the specific embodiments when read in conjunction with the drawings. that accompany it.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a plan view of the fluid operated tool according to an embodiment of the present invention; Figure 2 is a cross section of the side view of the fluid operated tool of fig. 1; Figure 3 is a side view of a fluid operated tool according to another embodiment of the present invention; and Figure 4 is a view showing the details of the fluid operated tool of Fig. 3 in an elongated view.

DESCRIPTION OF THE PREFERRED MODALITIES In Figs. 1 and 2 a fluid operated tool according to one embodiment of the present invention is shown. The fluid operated tool has rotatable coupling means for coupling and rotating a threaded connector, such as a nut, a bolt and the like. The coupling means are identified as a whole with the reference number 1 and include a ratchet 2 provided with an internal opening which for example has a hexagonal shape for coupling the nut, the bolt head, etc. The outer periphery of the pawl 2 has a plurality of teeth 4, and a rotating retainer 5 which engages the teeth 4. The fluid operated tool additionally has drive means which are connected to the coupling means for rotating the coupling means. The driving means are identified as a whole with the reference number 6. The driving means are formed as fluid-driven driving means and include in accordance with the present invention two fluid-operated driving elements. One of the fluid-operated driving elements is formed as a hydraulic motor, while the other of the elements is formed as a cylinder-piston unit 8. The fluid-operated driving elements 7, 8 are placed in a housing portion. 9 and adjacent to each other. The driving elements operated by fluid operated 7, 8 are joined together in the direction perpendicular to an axis of the driving means and in a plane extending perpendicular to the axis O of the coupling means. The hydraulic motor 7 is connected to the ratchet 2 through a transmission. The transmission includes an angular gear 10 connected to the arrow of the hydraulic motor, another angular gear 11 engages with the angular gear 10, a free rotation coupling including a first coupling half 12 fixedly connected with the angular gear 11 and a second half coupling 13 fixedly connected with a straight gear 14, and a straight gear 15 coupling with the straight gear 14 on the one hand and with the teeth 4 of the pawl 2 on the other hand. The cylinder-piston unit 8 has a cylinder 16 with a piston 17 which alternates in an internal chamber 18 of the cylinder 16 and provided with a piston rod 19. A working fluid is supplied to and withdrawn from the cylinder 16 through the the passages 20. The opposite end of the piston rod 19 rotatably engages a pin 21 connecting two drive plates 22 that transport the detents 5. Two side plates 23 are located on opposite sides of the drive plates 22 and from another portion of the housing . A valve 24 is provided between the chamber 18 of the cylinder-piston unit 8 and the hydraulic motor 7. The fluid-operated tool according to the present invention operates in the following manner.

When it is necessary to adjust a threaded connector, the working fluid is supplied to the driving means 6 and flows through the internal chamber 18 of the cylinder-piston unit 8 into the hydraulic motor 7 through the valve. During the initial stage of the adjustment of the threaded connector, for example a nut, it is displaced downwards until a corresponding object is reached, such as a flange or the like in which a bolt with the nut is screwed. During this initial stage there is a bit of resistance to the adjustment, and therefore the working fluid that freely flows within the hydraulic motor through the piston cylinder unit 8, activates the hydraulic motor 7, so that through the transmission of the ratchet 2 it is rotated with a high speed at a lower torque. Valve 24 is formed so that it is open when there is little resistance. When the threaded connector is displaced downward, and the setting with high torque is executed, a resistance of the threaded connector increases and as a result the valve 24 closes. The total energy of the working fluid now acts on the cylinder-piston unit 8, the piston 17 alternates and its piston rod 19 rotates the driver plates 22 with the detents 5 to rotate the ratchet 2 with a high torque that is necessary Separate the threaded connector fit. The coupling 12, 13 is designed so that the teeth of the coupling enclosure 12, 13 slide on each other during this step. Therefore, during the initial stage of the adjustment of the threaded connector, the ratchet 2 and therefore the threaded connector is rotated with a high speed at a lower torque by the hydraulic motor 7, while during the final stage of the adjustment of the threaded connector 2 and therefore the threaded connector is rotated with a high torque by the cylinder-piston unit 8. The fluid operated tool according to another embodiment of the present invention is shown in Figures 3 and 4. similar coupling means 1 including a ratchet 2 with an internal hexagonal opening 3 and a plurality of peripheral teeth 4. The driving means 6 'are formed in some different way. The driving means 6 'has a first piston cylinder unit 31 which includes a cylinder 32 with a piston 32 alternating in a chamber 34 and having a piston rod which engages a pin 35 which connects the driving plates 40 to each other. The driving means 6 'further has a cylinder-piston unit 36 with a cylinder 37 and a piston 38 which is alternately movable in a chamber 39. The piston 38 is also provided with a piston rod which butts against the driving plates 40. A valve 41 is positioned in a passage that communicates the chamber 34 of the first cylinder-piston unit 31 with the chamber 39 of the second cylinder-piston unit 36. In a normal condition it is closed although it is opened when a resistance exceeds a predetermined level. The fluid operated tool of Figures 3 and 4 operates as follows. In an initial stage of the adjustment of a threaded connector the working fluid is supplied through the passages 42 within the chamber of the first cylinder-piston unit 31, alternates the piston 33, and therefore rotates the ratchet 2 and a threaded connector coupled by ratchet with lower torque and high speed. When the downward movement is completed and the adjustment itself is initiated, a resistance of the threaded connector to rotation increases and a valve 41 provided between the cylinder-piston units 31, 36 opens so that the working fluid now flows into the chamber 39 of the second cylinder-piston unit 36. The piston 38 of the second cylinder-piston unit 36 alternates and applies additional force to the drive plates, so that now the ratchet 2 is rotated with a higher torque required for adjust the threaded connector. It is understood that the adjustment of a threaded connector is executed in a reverse order. In the tool according to the present invention in addition to the benefits of having a faster operation during the initial stage of the adjustment and a greater torque during the final stage of the adjustment, there is an additional advantage. Since the fluid operated impellers 7, 8 and 31, 36 are located adjacent to each other in a plane perpendicular to the axis of the pawl, the second housing portion 9 of the tool. This accommodates the drive means operated by fluid 7, 8, 31, 36 can be as thin as the first portion of the housing 42 accommodating the coupling means 2, 3, 4, 5 of the tool allowing better access of the tools in confined areas. It further eliminates that a larger housing portion rests on a surface that raises the point of engagement between the threaded connector (a nut) and the tool connecting means that are fastened near a portion of the threaded connector during operation. It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions that differ from the types described above. While the invention has been illustrated and described as it is presented in the fluid operated tool, it is not intended to be limited to the details shown, since various modifications and structural changes can be made without departing in any way from the spirit of the present invention. invention. Without further analysis, the foregoing will fully reveal the essence of the present invention that others, through the application of current knowledge, easily adapt it to the different applications without omitting the characteristics that, from the point of view of the prior art, clearly constitute the essential characteristics of the generic or specific aspects of this invention.

Claims (9)

1. A fluid operated tool for adjusting and loosening threaded connectors, comprising rotating coupling means for coupling a threaded connector for rotating the threaded connector and for adjusting and loosening the threaded connector; and driving means connected with the coupling means and acting on said coupling means for rotating the coupling means, the driving means including two fluid-operated driving elements connected to the coupling means and operated so that during an initial stage of the adjustment or a final stage of the loosening of a threaded connector one of the fluid-operated driving elements is driven and drives the coupling means, while during a final stage of the adjustment or a final stage of the loosening of a threaded connector is operated the other of the driving elements operated by fluid.

2. A fluid operated tool as defined in claim 1, and further comprising means for controlling the fluid operated drive elements such that during said initial stage of adjustment or the final stage of the loosening of the threaded connector only one is actuated. of the fluid-operated impeller elements, while only the other of the fluid-operated impellers is actuated during the final stage of the adjustment or the initial stage of the loosening of the threaded connector.

3. A fluid operated tool as defined in claim 1, and further comprising control means so that during the initial adjustment stage or the final stage of the loosening of the threaded connector only a fluid operated drive member is driven, while during the final stage of loosening of the threaded connector, both fluid-operated driving elements are actuated. A fluid operated tool as defined in claim 1, wherein said one fluid operated drive element is a hydraulic motor, while the other fluid operated drive element is a hydraulic cylinder-piston unit 5. A fluid operated tool as defined in claim 1, wherein a fluid operated driving member and the other fluid operated driving member are formed as hydraulic cylinder-piston units. 6. A fluid operated tool as defined in claim 1, and further comprising control means for driving the fluid-operated drive elements, the control means being formed such that a working fluid is initially supplied within the fluid. a fluid operated drive member and when a resistance to rotation of the threaded connector exceeds a predetermined value, the working fluid is supplied into the other fluid operated drive element. 7. A fluid operated tool as defined in claim 6, wherein the control means includes a valve that is provided between the fluid-operated impellers and is normally closed and that opens when the rotational resistance of the threaded connector exceeds the default value. 8. A fluid operated tool as defined in claim 1, and further comprising means for deactivating the fluid operated drive elements when a resistance to rotation of the threaded connector exceeds a predetermined value. A fluid operated tool as defined in claim 6, wherein the means for deactivation includes a free rotation coupling connecting a fluid operated drive member with said coupling element and disconnecting said fluid operated drive element. of the coupling element when the resistance to rotation of the threaded connector exceeds the predetermined value.