Fluid operated tool for elongating and relaxing a threaded connector

Abstract: A fluid operated tool for elongating and relaxing a threaded connector (1) has a fluid operated drive (4, 5) having an axis, a driving part (8) driven by the fluid operated drive (4, 5), and a reaction part, wherein the reaction part (13) includes a non-rotatable tool element (14) of the tool provided with first element (15) for engaging non-rotatably a threaded connector (1), the driving part (8) includes a rotatable tool element (9) rotatable about an axis of the threaded connector (1) and having second element (17) for engaging the rotatable tool element (9) with the non-rotatable tool element (14), and an intermediate element (19) arranged between the non-rotatable tool element (14) and the rotatable tool element (9), and being formed so that it engages with the non-rotatable tool element (14) so as to be non-rotatable as well while the rotatable tool element (9) freely turns relative to the intermediate element (19), whereby when the rotatable tool element (9) is turned about the axis, the non-rotatable tool element (14) only moves in an axial direction but does not turn and therefore displaces a threaded connector (1) in the axial direction.

Description: This invention relate to fluid operated tools, particularly for elongating and relaxing of threaded connectors, according to the preamble of claim 1 (see for example WO-A-93/22568). There are many different known fluid operated wrenches. Some fluid operated wrenches include a hydraulic drive, a driving part which engages a threaded connector and is driven by the drive so that, by actuating the drive, the driving part turns the threaded connector, and a reaction part adapted to counteract a force created during turning of the threaded connector. The reason for the provision of the reaction part is that, during turning of the threaded connector, a force is created tending to turn the tool in the opposite direction. It is necessary to counteract this force, which has been achieved in existing tools by the corresponding reaction part. In known fluid operated tools, such as for example the fluid operated tools disclosed in my US patent specifications US-A-4,201,099, US-A-4,336,727, US-A-4,368,655 and others, the reaction part is formed as an abutment element which is provided on the housing and adapted to abut against a stationary object located near the threaded connector to be tightened or loosened. While such a reaction part provides an efficient counteraction to the force tending to turn the tool in the opposite direction, it has some disadvantages. On the one hand it is always necessary to have a neighbouring object for the reaction part to abut against. On the other hand, the abutment against a neighbouring object has always been performed in these constructions in such a way that some of the parts which transmit the movement of the hydraulic drive to the driving part and also some of the parts in the driving part are subjected to forces which can break these parts. It is therefore clear that further modifications and improvements of such fluid operated tools are desirable. Accordingly, it is an object of the present invention to provide a fluid operated tool according to the characterising part of claim 1, which avoids the disadvantages of the prior art. In keeping with these objects and with others which will become apparent hereinafter, one feature of the present invention resides in a fluid operated tool as claimed in the ensuing claim 1. When the fluid operated tool is designed in accordance with the present invention it eliminates the disadvantages of the prior art and provides for the above mentioned highly advantageous results. The invention itself, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which: Figure 1 is a side view of one embodiment of a fluid operated tool in accordance with the present invention; and Figure 2 is a plan of the fluid operated tool of Figure 1. A fluid operated tool in accordance with the present invention is used for elongating and relaxing a threaded connector, such as for example a threaded stud 1. The fluid operated tool has a housing 2 which accommodates fluid operated drive means which conventionally includes a cylinder 4, a piston 5 reciprocatable in the cylinder under the action of a working fluid medium, a piston rod 6 extending outwardly beyond the cylinder 4 and pivotally connected with at least one driving plate 7 for turning the latter. The fluid operated tool has in addition to an inner sleeve 15', a socket 23 provided with inner splines 24 which engage with outer splines 25 of a non-rotatable projection 14' which is non-rotatably mounted on the housing 2 of the tool. The lower part (in Figure 2) of the socket 23 has inner splines 26 which engage with outer splines 27 of an intermediate element 19. The inner sleeve 15' does not have an upper part engageable with another part of the tool. When the reaction part is designed as shown, the inner sleeve 15' cannot rotate since it is non-rotatably engaged with the intermediate element 19 through splines 20, 21. The intermediate element 19 is further non-rotatably engaged, through splines 26, 27, with the socket 23, and the socket 23 is non-rotatably engaged through splines 24, 25 with the non-rotatable projection 14' of the tool. The driving part of the tool includes a rotatable tool element 8' formed as an outer sleeve 9'. The outer sleeve 9' has inner splines 28 which engage with outer splines 29 of a coaxial projection 10' of the ratchet wheel 11 which in turn is intermittently turnable by the pawl 12 mounted on the driving plate 7. The projections 10' and 14' are shown schematically in dashed lines in Figure 1. During the operation of the fluid-operated tool, the inner sleeve 15' engages with the stud 1 but cannot turn since it is connected with the non-rotatable intermediate element 19 which in turn is connected with the non-rotatable socket 23. Rotation of the stud 1 is thus prevented. Under the action of the fluid operated drive, the pawl 12 turns the ratchet 11 which in turn, through its projection 10', turns the outer sleeve 9'. The outer sleeve 9', with its lower end surface abutting against the end surface 22 of the intermediate element 19, freely turns relative to the latter. The inner sleeve 15' does not rotate but is displaced axially in response to the rotation of the outer sleeve 9' causing axial displacement of the stud 1 for elongating or relaxing the stud 1, depending on the direction of action of the fluid operated drive.

Claims: A fluid operated tool for elongating and relaxing a threaded connector, comprising a non-rotatable tool element (15') provided with first engaging means (16) for non-rotatably engaging a threaded connector (1); a rotatable tool element (9') coaxial with the non-rotatable tool element (15'), rotatable about an axis of the threaded connector (1) and having second engaging means (17) for engaging said non-rotatable tool element (15'); and an intermediate element (19) arranged and formed so that it engages with, but is non-rotatable relative to, said non-rotatable tool element (15'); the rotatable tool element (9') being freely turnable relative to the intermediate element (19) whereby, when said rotatable tool element (9') is turned about said axis, the non-rotatable tool element (15') only moves in an axial direction, but does not turn, and therefore is able to displace in the axial direction a threaded connector (1) when it is engaged with the latter; characterised in that the tool further comprises a housing (2); a fluid drive (4-7); a rotatable projection (10') which is rotatable by said fluid drive (4-7) and which is connected with said rotatable tool element (9') to rotate the latter; a non-rotatable projection (14') which is not rotatable relative to said housing (2), and a socket (23) which is non-rotatably connected with said non-rotatable projection (14') and said intermediate element (19) so as to prevent rotation of said non-rotatable tool element (15'); and in that said rotatable and non-rotatable projections (10' and 14') and said rotatable and non-rotatable tool elements (9',15') and socket (23) are coaxial with each other. A fluid operated tool according to claim 1, characterised in that said non-rotatable tool element (15') is formed as an inner sleeve (15') having an inner surface provided with said first engaging means (16) for engaging an outer surface (1') of the threaded connector (1) and an outer surface provided with a third engaging means (18), and in that said rotatable tool element (9') is formed as an outer sleeve (9') having an inner surface provided with said second engaging means (17) which engage the said third engaging means (18) of the non-volatable tool element (15'). A fluid operated tool according to claim 2, characterised in that said intermediate element (19) is formed as a ring having an end surface (22) and an inner surface provided with fourth engaging means (20) which engage said outer surface of said inner sleeve (15'), and in that said outer sleeve (9') has another end surface which is in contact with said end surface (22) of said intermediate element (19) during the free turning of said outer sleeve (9') relative to said intermediate element (19). A fluid operated tool according to claim 2 or 3, characterised in that said inner sleeve (15') has more surfaces cooperating with other parts of the tool., whilst said outer sleeve (9') has less surfaces cooperating with other parts of the tool. A fluid operated tool according to any one of the preceding claims, characterised in that said socket (23) is located radially outwardly of said rotatable and non-rotatable tool elements (9' and 15'). A fluid operated tool according to any one of the preceding claims, characterised in that said rotatable projection (10') is connected with said rotatable tool element (9') in a region axially adjacent a region in which said non-rotatable projection (14') is connected with said nonrotatable tool element (15') via said socket (23) and said intermediate element (19).

Inventors: JUNKERS JOHN K, JUNKERS, JOHN K.
Applicants: JUNKERS JOHN K, JUNKERS, JOHN K.
Application year: 1995
Main classification: B25B21
IPC codes: B25B5, F16B23, B25B23, F16B33, B25B21, F16B21, B25B13, B25B29, F16B31