AU7263094A

AU7263094A - Process and tool for rotating connecting elements, and connecting element used therewith

Info

Publication number: AU7263094A
Application number: AU72630/94A
Authority: AU
Inventors: Klaus-Hermann Ernst
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-08-09
Filing date: 1994-08-08
Publication date: 1995-02-28
Also published as: EP0713442B1; ATE166606T1; WO1995004635A1; PL312944A1; DE4495765D2; KR960703709A; BR9407222A; FI960617A; CA2169052A1; JPH09501110A; CN1128969A; EP0713442A1; FI960617A0; DE59406096D1

Abstract

A tool (1) for rotating rotary connecting elements (10, 17, 21) with a round or polygonal head, such as polygonal screws, nuts or round stud bolts, has a head (2) that may be set on or around the rotary connecting element and that is provided with an inner recess (4) for receiving the connecting element. An element (11, 12) movable transversely to the centre line of the inner recess with a pointed front face in the direction of the inner recess may be inserted or is arranged in at least one hole (5, 6) that extends substantially transversely to the centre line of the inner recess. Preferably two diametrically opposed holes (5, 6) with respect to the centre line of the inner recess are provided. An element with pointed front face may be inserted or is arranged in each of the holes. By tightening the pointed movable elements against the connecting element to be loosened, a highly-stressable connection is obtained, so that even completely round and/or tightly stuck screws, studs, nuts and the like may be reliably loosened.

Description

Description Tool for rotating rotatable connecting elements, method of rotating and in particular loosening rotatable connecting elements, and a rotatable connecting element The invention concerns a tool for rotating rotatable connecting elements, a method of rotating and in particular loosening rotatable connecting elements, and a rotatable connecting element. The tool has a head portion which can be fitted on to the connecting element, with an 5 internal opening for receiving the head of the connecting element. Those tools include all hand-operated or machine-driven socket wrenches, for example box wrenches, spark plug wrenches, wheel nut wrenches or machine-operated power socket wrenches. Torque wrenches, starter block wrenches and insert rings for freewheel ratchets and all 10 kinds of open-ended or jaw-type wrenches and ring spanners, for example divided ring spanners (also referred to as brake line spanners or wrenches) are included among the tools which are within the scope of the present invention. In gerieral the invention can be used in relation to any tool which is suitable for rotating rotatable and in particular 15 screwable connecting elements, in particular polygonal screw members, nuts or round connecting elements such as screw bolts or studs, and has a head portion which can be fitted on to the head of the connecting element and which has a suitably profiled internal opening. In that connection the tools may also be of a multi-part construction and for 20 example include the socket wrench inserts as well as the associated drives, ratchets, jointed handles and the like. In general the internal opening in the head portion of the tool is of such a configuration that it is suited to the generally standardised external contour of the screw which is to be loosened or 25 screwed fast. For example, in the case of socket wrench inserts (also referred to as socket tools) when designed for comercially available hexagonal screws, it has six crtwelve inside wall surfaces which extend in a straight line, in which case the screw to be screwed bears with the 2 edges of its screw head in the angle regions of the internal opening. When the tool is operated the turning force is thus applied to the screw by way of the outer edge regions of the screw head. The same also applies in the case of ring spanners or wrenches whose internal opening 5 passes completely through the head portion, and also for open-end wrenches which generally have two jaws with surfaces which extend parallel, wherein, in those types of wrench, the internal opening both extends through the entire head portion and is also laterally open on one side. 10 By virtue of the turning force being transmitted in that way primarily by way of the edge regions of the screw heads, particularly when dealing with older screws which have a certain material softening or fatigue effect, but also in the case of screws which are very tightly fixed, there is the problem that the force to be applied may 15 exceed the strength of the edge regions so that the edges are increasingly rounded off. That rounding-off effect of the edges may be to such an extent that the screw head generally becanes so greatly rounded that it can no longer be displaced by the camercially available socket, open-end or ring wrench. It is then necessary to 20 carry out special working operations involving shearing off the screw head or the like in order still to be able to slacken the screw. In that case however the screw is generally destroyed and there is also the serious risk of damaging the material which is clamped by the screw. In this case also the screwthread can be removed from the screw 25 hole, only with considerable difficulties. Those tools are also totally unsuitable for loosening round connecting elements such as for example screw bolts or studs. The object of the present invention is to provide a tool for rotating rotatable connecting elements, which is distinguished by 30 affording improved utility value. That object is attained by the features recited in claim 1. Advantageous configurations of the invention are recited in the appendant claims.

3 The invention also provides advantageous effective methods of reliably rotating and in particular loosening connecting elements with round or polygonal or corrugated heads, as well as a connecting element of a novel configuration which is especially effective in conjunction 5 with the tool according to the invention. The tool according to the invention thus has at least one and preferably at least two elements which is or are movable substantially transversely to the center line of the internal opening and provided with a pointed front surface. When the screw tool is used for loosening 10 a rotatable and preferably screwable connecting element, for example a polygonal screw member, the above-mentioned elements come into close contact with the screw head so that the force is also transmitted between the screw tool and the screw head by way of those additional elements. That provides additional locations at which forces are 15 applied so that the mutual bracing effect between the screw tool and the screw head of the polygonal screw member is improved. In particular the front tip, which tapers to a point, of the movable elements, ensures that - when just a relatively small amount of force is applied to the elements during the forward feed movement thereof - the movable 20 elements can dig into the material of the connecting element in an at least partially punctiform manner with a pressure in relation to surface area, which is very high as it acts in a punctiform manner, so that, between the movable elements and the connecting element, this configuration provides for a wedging action or a tooth-engagement 25 action in terms of the material used, which can be achieved with the application of a small amount of force and which is nonetheless highly effective, and that permits reliable loosening even of connecting elements such as screw bolts which are firmly held in position and/or which are completely round. In comparison, when using movable elements 30 with a flat front end surface, in principle it would not be possible to achieve a material wedging action or tooth-engagement action as referred to above.

4 If the engagement between the tips of the movable elements and the screw head is at a location which is displaced relative to an axially extending screw head edge, the points of engagement are on a circle of smaller radius than the normal force-transmitting point of 5 engagement between the inside surfaces of the screw tool and the screw head so that the risk of shearing off the screw head edges is considerably reduced or screw heads which have already been rounded off can still be loosened or tightened, with sufficient force. Preferably there are two holes, in each of which there is 10 disposed a movable element with a tip at its front end, which holes are disposed in mutually diametrally opposite relationship with respect to the center line of the opening. By virtue of that arrangement the round or polygonal head of the connecting element can be synmetrically clamped by the two movable elements so that the turning forces applied 15 also act symmetrically on the screw head and thus apply an optimum turning force thereto. Upon tightening of the movable elements, that is to say preferably the 'grub screws, the tips of the movable elements penetrate with their conical tip configuration into the material of the screw head so that this arrangement provides not only a force-locking 20 connection but also a positively locking connection which permits very high turning forces to be transmitted to the screw head. There is also the advantageous effect of an autanatic counteracting or locking action without additional means. more specifically, when the two pointed elements which are in the form in 25 particular of grub screws are tightened and thus press in punctiform contact firmly against the screw head or penetrate slightly into same, the two pointed elements each act as a locking means for the oppositely disposed grub screw and press it against its own screwthread pitches so greatly that - without the need for additional locking means - even 30 only slight rearward displacement of the grub screws when loosening the screw member is also reliably avoided. That means that the grub screws autcmatically lock each other in position and permit the transmission of a high level of turning force.

5 In addition, by virtue of the resulting effect of the connecting element being clamped between the oppositely disposed tips of the movable elements, it is possible to prevent the connecting element being pressed against the side surface of the opening in the tool. In 5 that case the transmission of turning force is produced exclusively by way of the tips of the movable elements so that for example it is possible to avoid the risk of damage to or further rounding-off of the side edges of the polygonal head of the connecting element. Thus, the tool according to the invention reduces the risk of 10 damage or deformation when tightening or loosening even softer, older or firmly fixed screw members, and the tool can also reliably deal with screw heads which are already deformed. The tool however is also highly suitable for screwing on or screwing in elements, for example screw bolts, which are completely round from the point of view of their 15 design. It will be appreciated that nuts or the like can also be loosened or tightened by the tool according to the invention. The tool according to the invention is also suitable for screwing on or screwing in screw members with heads having a round or corrugated outside periphery such as for example screws with a hexagonal recess therein, 20 with straight or corrugated inside surfaces (Intbus-screws, Tor screws) or TorxP-screws with a head having a corrugated outside periphery. In a preferred enbodiment the holes which accommodate the elements are not only in the form of blind holes which are accessible 25 from the inside but they are in the form of holes which extend entirely through the head portion so that the elements which are disposed in the holes can also be actuated and possibly introduced from the outside. That makes it easier to handle the tool according to the invention as now for example the tool can firstly be fitted to the connecting 30 element, for example the screw head, in the usual way, and thereafter the movable elements are brought into engagement with the screw head by being actuated fran the exterior. All holes and thus all movable elements are preferably disposed in a single plane which extends at a 6 right angle to the center line of the opening so that the axial length of the tool can be kept small. The movable elements may be of any configuration. In a preferred embodiment however they involve screw pins or grub screws or set 5 screws, in which case the through holes receiving the grub screws have a corresponding internal screwthread. In that case, when they are not in use, the grub screws are reliably held in the through hole and in addition can be easily replaced in the event that they suffer from wear or if necessary they can also be replaced by a different grub screw 10 with a grub screw tip of a different profile. When the grub screw is tightened after the tool has been fitted on to the screw head, it can cane into direct engagement with the screw head and can apply considerable forces thereto when the tool is turned, as the grub screw is reliably prevented fran moving back, by virtue of its screwthread 15 engagement. Preferably the material of the movable elements affords a higher level of tensile strength than the connecting elements to be loosened so that the turning force can be transmitted by way of the elements, without the risk of damaging them. 20 in an alternative configuration it is also possible to arrange between the tip of the movable element, in particular the grub screw, and the head of the screw member, a movable element disposed in the interior of the head portion of the tool, for example a ball or preferably a cone which is moved or biased forwardly in a direction 25 towards the screw head by the screw or another element which can preferably be fixed in its respective position, and, when not in use (or before the tool is fitted on to the screw head) can be moved back into a retracted position in which it does not project into the internal opening in the head portion of the tool. Alternatively, a 30 movable element for example in the form of a leaf spring which is clamped at one end in the head portion, with a laterally projecting tip or edge, may be provided between the grub screw or the adjusting 7 element which is of sane other configuration, and the head of the connecting element. In that case the leaf spring is so positioned in its normal position that it terminates flush with the inside wall of the internal opening in the tool. After the tool is fitted for example 5 on to the screw member to be operated, the leaf spring can then be biased towards the screw head by the adjusting element which is disposed in the head portion, and in that case canes into firm engagement with the screw head so as to produce a bracing action between the head portion of the tool and the screw head, which permits 10 a better transmission of force than hitherto. When using such an intermediate element, the center line of the through hole does not necessary have to coincide with the position in respect of height of a screw head which is introduced into the screw tool but, with respect to the front surface of the tool which is 15 towards the screw, the center line of the through hole may be set back further rearwardly than the screw head extends inwardly. In a preferred embodiment however the spacing between the center line of the holes and the front surface of the head portion (the front surface forms the insertion opening for the screw head) is smaller than 20 the axial thickness of the screw head of the screw which is to be actuated by the tool. That provides that the movable element acts directly axially on the screw head and it is thus possible to achieve optimum bracing thereto. The holes are preferably so oriented that they intersect at a 25 right angle a flat inside wall surface of the internal opening of the head portion. That means that the movable element moves at a right angle towards the connecting element, for example the screw bolt or the screw head, and can ccme effectively into engagement therewith. In that respect it is preferred that the holes extend exactly at a right angle 30 to the center line of the internal opening in the head portion. That arrangement ensures that the exit point of the holes lies directly on a line bisecting a straight surface of the screw head to be actuated, and 8 thus acts at a point on a circle with the smallest radius on the outside of the screw head. When the screw tool is turned therefore the tips of the movable elements effectively wedge themselves in the material of the screw head so that it is reliably possible and without 5 a major risk of damage to turn even rounded, round-headed, older and/or very firmly fixed screw members. As an alternative however it is also possible for the holes to extend at a certain angle relative to the radius line of the head portion so that the movable element acts inclinedly on the head of the 10 connecting element. That makes it possible to provide a preferential direction in regard to the transmission of force, for example such that, in a slackening operation, the movable element is brought into firmer engagement with the surface of the screw head than in a screw tightening operation. In that case the holes are arranged inclinedly in 15 the head portion in such a way that, as viewed in the direction of the movement of the head portion when loosening the screw member, the holes are at a greater spacing relative to the radius line of the head portion, at a radially further inwardly disposed position, than at a radially further outwardly disposed position. 20 The number of holes in the head portion and thus also the movable elements in the holes can be suitably selected. For example, when dealing with relatively large screw heads, in addition to the two diametral holes, it is possible to provide further holes having movable elements, for example one for each screw head side surface. For 25 example, there may be four holes with movable elements at angular spacings of 90* in each case. It is also possible to provide for example three holes having movable elements which are disposed therein or which are to be arranged therein, at equal mutual angular spacings of 1209. 30 The invention can be used with all kinds of screw tools for actuating round or polygonal connecting elements, for example polygonal screw members, for example in the case of inserts for socket wrenches 9 or in the case of the socket wrenches themselves, in particular for box wrenches, spark plug wrenches, wheel nut wrenches or machine-operated power wrenches. The tool may also be an insert ring for freewheel ratchets or a socket tool or a socket wrench insert. In general terms, 5 any hand-operated or machine-driven screw tool falls to be considered as the tool according to the invention, for example including open-end wrenches (jaw-type wrenches) or divided or undivided ring wrenches or spanners. Obviously - or even exclusively - the screw tool according to the invention can also be used for slackening and/or tightening nuts, 10 screw pins or the like. The configuration of the internal opening in the head portion may be of a round or polygonal cross-section and has for example three, four, six or twelve rectilinearly extending inside wall surfaces which intersect each other at an angle, wherein the number of inside wall 15 surfaces can be adapted to the respective number of rectilinearly extending outside surfaces on the screw member to be actuated or can be a multiple thereof, in most cases double same. The tool according to the invention is distinguished by universal utility. For example, it permits use both in connection with metric and 20 also inch size systems. By screwing in the movable elements fran different and in particular oppositely disposed sides, into the tool, until they come into engagement with the connecting element to be turned by the tool, the difference in size between connecting elements in accordance with the metric system and the inch system can be 25 canpletely canpensated. Therefore the user now no longer has to provide separate specific tool sets for metric and inch systems, but with a single tool, can deal with a respective multiple of different connecting elements of different sizes or with different head shapes (round, polygonal or corrugated cross-section). 30 Furthermore, by virtue of the tips of the movable elements engaging with the connecting element to be operated on, the tool affords a much better grip on the connecting element so that the risk 10 of the tool undesirably slipping off the connecting element is significantly reduced. That also significantly reduces the risk of injury to the user. The movable elements which are preferably in the form of grub 5 screws are preferably of a screwthread diameter of frcm about 3 to 4 mn. In the case of larger tools however it is of course also possible to use larger grub screws. In accordance with the invention it is also possible for the movable elements to be screwed into the tool to different extents, so 10 that the axis of the screw connecting element is displaced relative to the center line of the tool opening. When the tool is rotated, it therefore acts eccentrically on the connecting element. It has been found that, in that way, the forces which are transmitted by way of the tips of the elements permit even more effective loosening of even very 15 firmly fixed screws, presumably by virtue of material being displaced and piled up in front of the tips to different degrees, in an initial slight rotation of the tool relative to the connecting element. If there should be little or no space for actuating the movable elements at the location of use of the tool, it is also possible in 20 accordance with the invention that, before the tool is fitted on to the connecting element to be loosened, the movable elements are screwed in to such an extent that the mutual spacing between their tips is smaller than the thickness of the head of the connecting element in that region. Thereupon the tool can then be knocked on to the connecting 25 element, in which case the tips of the elements dig in a channel form through the peripheral surface of the connecting element. When the screw tool is then turned, additional material possibly builds up in front of the tips of the elements and the tips of the elements which have dug into the material entrain the connecting element so that the 30 latter is loosened. The invention also provides a novel connecting element which has at least one opening or hole into which the tip of the movable element can pass when the tool is fitted. That makes it possible to provide a force-locking and positive-locking connection which can carry a high loading and which permits even very firmly fixed connecting elements to be loosened or which permits such connecting elements to be firmly tightened, without the grub screws having to be dug deeply into the 5 material of the connecting element. The invention is described in greater detail hereinafter by means of a preferred embodiment with reference to the drawings in which: Figure 1 shows an embodiment of the tool according to the invention in the form of a socket wrench insert, 10 Figure 2 is a side view of the tool illustrated in Figure 1, with the plane of viewing turned through 90*, Figure 3 shows a front view of the embodiment illustrated in Figures 1 and 2, Figure 4 is a sectional view of the tool illustrated in Figure 1 15 in section along section plane A-B illustrated in Figure 1, Figure 5 shows an aTbodiment of the tool according to the invention in the form of a ring and/or open-end wrench, Figure 6 shows a partly broken-away view of the tool illustrated in Figure 5, 20 Figures 7 and 8 show a modified enbodiment of the tool shown in Figures 1 through 4 with a connecting element in the form of a screw bolt, and Figures 9 and 10 show an embodiment of a connecting element according to the invention. 25 The enbodliment of the tool according to the invention, as shown in Figures 1 through 4, is in the form of a socket wrench insert 1 having a head portion 2 and a drive portion 3. The head portion 2 is provided with an internal opening 4 which, as can best be seen fran Figure 3, is in the shape of a hexagon as viewed in cross-section. The 30 drive portion 3 in turn has a square opening 7 for engagement with a drive element (not shown), for example a ratchet, a winch unit or an extension. A transversely extending through bore 8 may be provided in 12 the drive portion 3, which however does not possess any function in regard to rotational actuation of the socket wrench insert, but is only intended to prevent the socket wrench from being axially pulled out of the opening 7. 5 In accordance with the invention the socket wrench insert is provided with two transversely extending through holes 5, 6 which have an internal screwthread. As can be seen fran Figure 3 the two through holes 5, 6 are disposed in mutually diametrally opposite relationship and extend at a right angle to the rectilinear inside wall surfaces of 10 the opening 4, their center line lying directly in the line bisecting the rectilinear inside wall surfaces. It will be seen fran Figure 4 that the spacing between the front surface of the socket wrench insert 1, by way of which a screw head 10 of a screw manber 9 is guided into the internal opening 4, and the 15 center line of the through holes 5, 6, is smaller than the axial thickness of the screw head 10. The through holes 5, 6 thus open directly on to the rectilinear outside edges of the screw head 10. As shown in Figure 4, screwed into each of the through holes 5, 6 are respective screw pins 11, 12 which are preferably in the form of 20 grub or set screws with front surfaces which taper to a point, with the pointed tips of the grub screws lying concentrically on the center line of the grub screws. Those preferably hardened grub screws thus press with their pointed front surfaces centrally on to the outside surfaces of the screw head 10 which has been introduced into the internal 25 opening 4. Preferably in that respect the screw pins 11, 12 are screwed slightly outwardly by means of a screwdriver or the like, before the screw head 10 is introduced into the opening 4, so that the insertion opening is fully open and the screw head 10 can be introduced into the internal opening 4 virtually without applying a force thereto. The 30 screw pins 11, 12 are then turned in such a way that they move inwardly, more specifically to such an extent that their tip surfaces bear directly against the outside surfaces of the screw head or press 13 into same in punctiform fashion or by virtue of their conical tip configuration. When the socket wrench insert 1 is then turned therefore the turning force is transmitted to the screw head 10 not only by way of the corner regions of the screw head and the internal opening 4, but 5 in particular also by way of the screw pins 11, 12, so that this provides an extremely effective, force-locking connection. In that way even screw members which are a very tight fit and which for example have rusted in position, or screw members which are already rounded off, can be slackened (for example by striking the tool), without a 10 special tool being required. Also, when tightening a screw member, correspondingly increased screw forces can be transmitted to the screw member fran the socket wrench without the risk of damage thereby. In embodiments which are not shown herein the tool may also be formed by an insert ring for freewheel ratchets, wherein the holes and 15 the movable elements disposed therein preferably pass not only through the insert ring but also through the externally embracing ratchet ring so that the movable eleinents can be actuated fran the exterior. Open end wrenches and ring wrenches or spanners may also be provided with the through holes according to the invention and movable elements which 20 are accamodated therein, in particular in the form of screw bodies, wherein the relative arrangement between the through holes and the screw bodies on the one hand and the head of the screw member to be actuated on the other hand is preferably of the configuration shown in Figure 4. It will be appreciated that in such a case the portions shown 25 in Figure 4 to the right of the end face of the screw head are omitted. Figures 5 and 6 show an embodiment of the tool according to the invention in the form of a wrench 13 which at its upper end is in the form of a ring wrench and at its lower end in the form of an open-ended wrench. However the wrench 13 may also be formed at both ends either 30 only as a ring wrench or only as an open-ended wrench, with different wrench sizes.

14 At its upper. end the wrench 13 has an opening 14 in the form of a ring, with twelve sides therein, which is designed to receive a polygonal screw head of corresponding size, but which can also be pushed on to the head of a round connecting element. Provided in the 5 outside ring which surrounds the opening 14 are two through bores 5, 6 for receiving movable elements in the form of grub or set screws 11, 12 which extend at a right angle to the center line of the opening 14 and which intersect the twelve-sided configuration of the opening in the region of a projecting inside edge. 10 As can be seen from the Figures, the grub screws 11, 12 which are preferably made fran hardened material are provided with front surfaces which centrally converge to a point, and at their rearward ends they have a recess with an internal hexagon. An Inbus wrench 15 (for engaging into a hexagonal recess)is used for actuating the grub screws. 15 Alternatively however the grub screw may also be provided with a turning slot or the like, at its rear end. At the lower end of the wrench 13 the opening 16 is of a jaw-like configuration provided by two parallel jaws, wherein the holes 5, 6 extend in mutually directly oppositely disposed relationship at a right 20 angle to the inside jaw surfaces and issue substantially centrally from the internal jaw surfaces. Figure 5 shows the grub screws 11, 12 in the condition in which they have not yet been screwed into the wrench, while in the partly broken-away view shown in Figure 6 the grub screws 11, 12 are screwed 25 into the holes 5, 6 in the tool 13. As can be seen from all views, the grub screws 11, 12 are preferably longer than the holes 5, 6 so that, even in the fully screwed-in condition, they still project on the outside and are thus readily accessible. It will be appreciated however that they can also 30 be shorter. Figures 7 and 8 show a further enbodiment of the tool in the form of a socket wrench unit (socket wrench insert) 1' which, with the exception of the round cross-section of the internal opening 4', is 15 ccnpletely identical to the embodiment shown in Figures 1 through 4. The round cross-section of the opening can best be seen frcm the left hand front view in Figure 8. The socket wrench insert 1' is designed for actuating a round screw connecting element in the form for example 5 of a screw bolt 17, but it also makes it possible to turn polygonal screw heads, nuts and the like, which are introduced into the opening 4'. The screw bolt 17 is of the usual round configuration with an externally screwthreaded portion 18 and a round head portion 19 in 10 which there is provided an actuating portion 20 for example in the form of an internal hexagon. In the normal case, for unscrewing or screwing up the screw bolt 17, the head portion 19 thereof is introduced into the opening 4' and then the grub screws 11, 12 are screwed in to such an extent that their tips dig into the surface of the head portion, 15 whereafter the tool 1' is turned by way of an extension lever and/or ratchet lever or the like. Figures 9 and 10 show two different side views of an embodiment of the rotatable or screwable connecting element according to the invention, in the form of a screw bolt 21. In the same manner as 20 the screw bolt 17 shown in Figure 7, the screw bolt 21 is of a round configuration with an externally screwthreaded portion 22 and a round head portion 23 in which there is provided an actuating portion 24, for exaple in the form of an internal hexagon. In addition the screw bolt 21 has two diametrally oppositely 25 disposed conical openings 25. The tips of the grub screws 11, 12 can engage into the openings 25 in use of the tool according to the invention, thereby producing a rotational connection which can carry a high loading and which at the same time also prevents the connecting element fran unintentionally falling out of the tool. The 30 number and position of the openings 25 preferably depend on the number and position of the movable elements in the tool. Instead of the conical openings 25 it is also possible to provide openings of another configuration, for example through holes.

16 The connecting element according to the invention can also be designed as a screw member, stud with a substantially continuous external screwthread, nut or the like, with openings 25 which are arranged in the outside periphery of the head and which are of a 5 conical or other configuration.

Claims

1. A tool for rotating rotatable connecting elements, in particular polygonal screw members, nuts or round connecting elements, for example studs, having a head portion (2) which can be fitted on to or applied to the rotatable connecting element (9; 17; 21) and which has an internal opening (4; 4'; 14; 16) for receiving the connecting element (9; 17; 21) and at least one hole (5, 6) which extends substantially transversely to the center line of the internal opening and in which an element (11, 12) which is movable transversely to the center line of the internal opening, with a front end which tapers to a point in the directionof the intsamal opening, can be disposed or is arranged.

2. A tool as set forth in claim 1 characterised in that there are two holes (5, 6) which extend substantially transversely to the center line of the internal opening (4; 4'; 14; 16) and which are disposed in diametrally opposite relationship with respect to the center line of the internal opening and in each of which an element (11, 12) which is movable transversely with respect to the center line of the internal opening, with a pointed front end, can be disposed or is arranged.

3. A tool as set forth in claim 1 or claim 2 characterised in that the hole or holes (5, 6) pass through the entire wall of the head portion.

4. A tool as set forth in claim 1, claim 2 or claim 3 characterised in that the elements (ll, 12) are in the form of a screw pin or a grub screw with a front point and that the holes (5, 6) carry an internal screw thread.

5. A tool as set forth in one of the preceding claims characterised in that the spacing between the center line of the holes (5, 6) and the front surface of the head portion is smaller than the axial thickness of the head of the connecting element (9; 17; 21) to be actuated by the tool. 18

6. A tool as set forth in one of the preceding claims characterised in that the holes (5, 6) are so arranged that they intersect at a right angle a flat inside wall surface of the internal opening (4) of the head portion (2).

7. A tool as set forth in one of the preceding claims characterised in that the holes extend precisely at a right angle to the center line of the internal opening (4; 4'; 14; 16) of the head portion (2).

8. A tool as set forth in one of the preceding claims characterised in that the tool is a socket wrench, in particular a box socket wrench, a spark plug wrench, a wheel nut wrench or a machine operated power socket wrench.

9. A tool as set forth in one of claims 1 through 7 characterised in that the tool is an insert ring for freewheel ratchets or a socket wrench insert.

10. A tool as set forth in one of claims 1 through 7 characterised in that the tool is an open-end wrench (jaw-type wrench) or a ring wrench.

11. A tool as set forth in one of the preceding claims characterised in that the internal opening (4') is of a round cross section.

12. A tool as set forth in one of claims 1 through 10 characterised in that the internal opening (4) is of a polygonal cross section, preferably with three, four, six or twelve rectilinearly extending inside wall surfaces which intersect each other at an angle. 19

13. A tool as set forth in one of claims 1 through 10 characterised in that the internal opening (4) is of a corrugated cross section.

14. A method of rotating and in particular loosening a rotatable connecting element by means of a tool as set forth in one of the preceding claims characterised in that the tool is firstly fitted on to or applied to the connecting element to be loosened and then one or more of the movable elements (11, 12) is moved towards the connecting element, particularly by screwing in the movable element or elements, to such an extent that the tip of the movable element or elements digs into the surface of the connecting element, whereafter the tool is rotated.

15. A method as set forth in claim 14 characterised in that firstly one of the movable elements is moved into the opening to such an extent that, by virtue of the contact between said movable element and the connecting element, the center line of the connecting element is displaced relative to the center line of the opening, and then the oppositely disposed movable element is dug with its tip into the connecting element, and then the tool is rotated.

16. A method of rotatating and in particular loosening a rotatable connecting element by means of a tool as set forth in one of claims 1 through 13 characterised in that firstly, before the tool is fitted on to the connecting element, the movable element or elements (11, 12) is moved into the tool, in particular by screwing the movable element or elements in, to such an extent that the free space between them is smaller than the thickness of the head region of the connecting element and then the tool is knocked on to the head region of the connecting element so that the tips of the movable element or elements dig into the surface of the connecting element, whereafter the tool is rotated. 20

17. A rotatable connecting element for use with a tool as set forth in one of claims 1 through 13 characterised in that provided in the head region of the connecting element is at least one opening (25) or a hole at a position such that the tip or tips of the movable element or elements can be introduced into the opening or openings or the hole or holes.