Washer and fastener provided with a washer

European).

ΕΡ 1 577 569 Bl

Description

The present invention relates to a washer and to a fastener fixed with a washer.

It is known to fasten objects together to one another by means of mechanically driven tools, in which fasteners having a multi-piece replaceable nut, including, for example, an inner sleeve, an outer sleeve and a washer are used. Such a replaceable cap is disclosed, for example, in US-A-5,341,560. US-B-6,254,323 discloses another interchangeable nut, in which the screw, at the bottom under its thread located above, has a spline to which the washer is connected without rotation, and this screw also has an interlocking system for exerting reaction force, while the active force of the same tool twists the nut, moving it on the screw thread and on the face of the washer. Common features found in the connectors disclosed in both of the above patents are: utilization of the active force and reaction force of one tool, elimination of reaction levers on mechanically driven tools, conversion of torque to tensile force acting on a non-torsion screw, and obtaining for the first time the required residual load of the screw rather than the required torque, which is estimated based on rather for calculated friction forces than for actual friction forces, or estimated based on a tensile force that is based on the relaxation effect in the screw when the force is transferred from the elongated screw to the hand-clamped nut.

In this patent application, the term "screw" is used in a very broad sense to encompass any fastener provided with a thread, such as a screw, stud, screw, threaded rod, tension pin, through screw, pipe plug screw, and the like.

Some solutions are disclosed in the publications: US 2003-0183045 A1, US 2003-0106396 A1, US 2003-0198533 A1 and US 6,609,868 B2.

The object of the present invention is to provide a washer and connector with a washer that provide further solutions to the above problems.

The present invention, in its one form, provides a washer according to claim 1. Recommended or optional features of this washer are defined in claims 2 to 8.

According to another embodiment of the present invention, a connector according to claim 9 is provided.

When a washer and connector are designed in accordance with the present invention, the bolt, which usually tends to twist with the nut, is prevented from rotating by friction caused by at least one anti-rotation surface of the washer body that interacts with the bolt, and the washer body is prevented from twisting due to the friction caused by the other end face of the washer, which cooperates with the object and at the same time the nut, when turning it, shows the least possible friction resistance coming from the first face of the washer body and therefore, in the process of its rotation, it does not participate in cooperation with the washer body, except that the friction between the second surface the front washer and object stops the washer from turning even more confidently, and the friction between the anti-rotation surface of the washer body and the object further restrains the screw from rotating with the nut.

ΕΡ 1 577 569 Bl

The invention, both its structure and mode of operation, together with additional goals and benefits resulting from it, will be best understood from the following description of specific characters given here only in an exemplary form, when this description is read in conjunction with the accompanying drawing , on which:

Figure 1 is a view showing a pad according to the present invention;

Figure 2 is a view showing a fastener with a washer and the tool applied to the fastener and the fastening method according to the present invention;

Figure 3 is a view showing a further example of a washer according to the present invention;

Figure 4 shows a still further embodiment of the pad according to the present invention;

Figure 5 shows an additional form of the washer of the present invention, and

Figure 6 shows a further embodiment of the pad according to the present invention.

Figure 1 shows the washer according to the present invention, which is indicated by reference number 1 as a whole. The washer 1 has a body marked with reference number 2. The body 2 of the washer 1 has an axis A1, a first upper face 3 adapted to work with a nut, a second lower face 4 adapted to work with an object that can be formed as two parts to be assembled with each other, and at least one additional, counteracting turning, the surface marked with reference number 5.

The front surfaces, first 3 and second 4, are spaced apart, one from the other, in the axial direction, in other words in the direction of the axis A1. At least one additional anti-rotation surface 5 is located radially, inside the body 2 of the washer 1. The surface 5 is formed so that it interacts with the screw friction preventing the screw from turning while the nut is turned and the screw is urged to rotate with it . The anti-rotation surface 5 can be formed to engage the thread or wedge on the screw thread, for example by inserting on the surface 5 a thread 6 corresponding to the screw thread.

As can be seen in figure 1, the body 2 of the washer 1 is composed of two parts, 7 and 8, arranged radially, in fact one adjacent to the other, so that part 7 is inside the part 8 being radially positioned therein. A surface 5 with a thread 6 that counteracts the rotation of the screw is arranged radially inside the part 7. Part 8 has a projection 9, which is above the part 7 and prevents the axial upward movement of part 7. The projection 9 of the part 8 forms local resistance, which in this form is formed as breaking resistance. More specifically, projection 9 is designed so that it can break under the action of a certain force acting axially upwards.

While the surface 5 of the washer body 2 is formed to prevent the screw from turning while the nut is turning, the washer body 2 is also formed so that its twisting in this process is prevented. Especially the bottom face 4 of the body 2 is shaped as a friction surface, on which friction is important in friction cooperation with the object, so that when the nut is turned and it causes the screw to turn, which in turn causes the washer to turn, the washer body does not actually he was spinning, or was being held back, because of frictional cooperation between the second face 4 and the object. In order to provide an increased coefficient of friction on the surface 4 of the washer body 2, the roughness of the bottom face 4 can be further increased, the friction enlarging coating applied, and so on.

-2ΕΡ 1 577 569 Bl

On the other hand, the upper face 3 that cooperates with the nut is formed so that it has a lower coefficient of friction than the lower face 4 which cooperates with the object. In particular, it can be formed so as to give the lowest possible coefficient of friction between the body 2 of the washer and the nut, so that when the nut is rotated, it, in the process of rotation, does not actually pull (not drag) the body of the washer 2 because the washer must be held in a non-rotating position to keep the screw from turning. To this end, the top face 3 of the washer can be machined so that it has very low roughness and high sliding properties, a coating to reduce the coefficient of friction can be applied to it, and so on. It is also possible to manufacture the washer body such that its upper face 3 is machined to reduce friction, and its lower face is left without machining and is rough.

Figure 2 shows a connector equipped with a washer and a tool applied to the connector. The connector has a nut 10 having an internal thread 11. Further, the connector has a screw 12 equipped with an external thread 13, and has an axis A2. The nut 10 has a bottom face 14 that is adapted to be placed on the top face 3 of the body 2 of the washer 1. The external thread 13 of the screw 12 interacts with the internal thread 11 of the nut 10, and also interacts with the internal thread 6 of the body 2 of the washer 1.

The power-driven tool used with the washer of the present invention is designated by reference number 15. The power-driven tool has a housing which is designated by reference number 20, and has a mechanical drive which is designated by reference number 21. The mechanical drive is formed, for example, in the form of a cylinder-piston unit, comprising a cylinder 24 and a piston 25 having the possibility of sliding movement in this cylinder and equipped with a piston rod 26. The reciprocating movement of the piston rod 26 with the piston 25 is converted into the rotational movement of the ratchet wheel 28 by at least one drive plate 27 equipped with a not shown pawl having the ability to engage with the teeth of the ratchet wheel 28. The drive element 16 is connected, one on the side with the rotatable ratchet wheel 28, and on the other side cooperates with the nut 10. In order to ensure such cooperation, the inner surface of the driving element 16 may be equipped with a connecting system, for example, with an inner surface formed into a polygonal shape.

The mechanically driven tool additionally has a non-rotatable element 17 which is connected to the fixed housing 20 to suppress the interaction of the driving element produced during its rotation. The non-rotatable element 17 interacts with the body 2 of the washer 1 preventing it from turning about axes A1 and A2, which axes overlap each other when the connector is assembled. For interlocking with the washer, the non-rotatable element 17 may be provided with a connecting system formed, for example, in the form of a socket with a polygonal inner surface cooperating with the polygonal peripheral surface of the body 2 of the washer 1.

The fastener, together with the washer, is provided for fastening the object, which is indicated by the reference number 18, for example for mutual assembly of parts 19 and 19 'of the object 18 together.

When, as can be seen in figure 2, the power tool 15 is applied to the fastener so as to tighten or loosen the nut, the rotating element 16, which is connected to the nut 10, turns the nut overcoming the friction present on the thread of the screw 12, and the friction on frontal surface

-3“

5 1 577 569 Bl of washer 1 (which according to the present invention may be very small), so the nut is rotated, and the non-rotatable element 17 holds the washer to absorb reaction force due to friction on the faces of washer 1 and nuts 10 (which friction according to the present invention may be very small), friction on the face of the washer in contact with one side of the part 19 ', and friction from rotation on the screw 12; so that the washer 1 does not rotate but absorbs the reaction force from the power-driven tool. Initially, when the nut 10 rotates, the screw 12 rotates together with the nut; however, the resting washer 1 wedges the fixed part 7 on the threads of the bolt 13, so that the bolt stops rotating because it is meshed with one another by its external thread 13, with the thread 6 of the washer 1. Thus, the screw 12 is stopped and an axial force, which acts in particular on part 7 of the washer 1, is applied to the washer 1 in the axial direction upwards when the screw 12 is elongated when the nut is turned. Under this upward axial force, the local resistance in the washer is overcome, and more precisely, the projection 9 of the washer 1 part 8 breaks off and the washer part 8 is pulled up.

Figure 3 shows another form of washer according to the present invention. There is a washer here, which is marked with the reference number Γ, it has a body 2 ', which is formed as a one-piece unitary element with a partition 31 and a groove 32 provided here to reduce the thickness of the partition and make it vulnerable to breaking.

The operation of the washer Γ, according to the second embodiment of the present invention, is in fact similar to the operation of the washer 1 having the form shown in figure 1. When the nut 10 is rotated by means of the power tool drive element 16, the screw 12 tends to spin together with nut. When the washer Γ is stopped in place and, as a result, its inner part 7 'is immobilized, the screw becomes stationary due to the mutual engagement of its outer thread 13 with the internal thread 6' of the body 2 'of the washer 1', but it is elongated towards axial direction. The axial force that is generated when extending the screw 12 is applied axially upwards on the radially inwardly positioned part 7 'of the washer 1' and it attempts to move the inner part 7 'so that it finally breaks the partition 31 which is local resistance, and moves this inner portion 7 'of the washer 1' axially upwards relative to the outer portion 8 '.

Figure 4 shows a further embodiment of the pad according to the present invention. There is a washer here, which is marked with the reference number 1 ", it has a body 2". The body 2 "washer 1" has a first upper 3 "face adapted to work with the nut, a second lower 4" face adapted to work with the object, and has an anti-rotation surface marked with the reference number 5 ". The anti-rotation surface 5 "is located radially internally and is formed to engage with the screw thread by wedging on it, for example as a 6" anti-rotation surface 6 "thread corresponding to the screw thread. The body 2 "washer 1" is composed of two parts, 7 "and 8", arranged radially, in fact one adjacent the other, so that the part 7 "is placed radially inwardly in the part 8". The anti-rotation surface 5 "with a 6" thread is located radially inwardly in the part 7 ".

Part 7 "has a conical shape of the periphery 33, which is embedded in the lower part 34 of the hole in the part 8", with the shape corresponding to it. Formation 33, 34 creates local resistance in the washer. When part 7 "is pulled up, when stopped turning the bolt, the shape of the rim 33 parts 7 "is

-4ΕΡ 1 577 569 Bl slightly but permanently deformed and brought to the size of the part with a simple form entering the hole in the 8 "part, allowing the 7" part to move further up the hole, as the screw lengthens.

Figure 5 is a view showing a further embodiment of the present invention. The washer is marked with the reference number Γ "and has a 2" body. The body 2 "of the washer 1" 'has a first upper face 3 "' adapted to work with the nut, a second lower face 4" "adapted to work with the object, and has an anti-rotation surface marked with the reference number 5" '. The anti-rotation surface 5 "'is located radially internally and is formed to engage with the screw thread by wedging on it, for example as a 5" "anti-rotation surface, 6" thread corresponding to the screw thread. The body 2 "'of the washer 1"' is composed of two parts, 7 "'and 8"', arranged radially, in fact one adjacent to the other, so that the part 7 "'is placed radially inwardly in the part 8"'. The anti-rotation surface 5 "'with 6" thread is located radially inwardly in the part 7 "'.

In the embodiment shown in Figure 5, the part 7 "'is provided with a bottom part with an externally knurled part 35 having the shape corresponding to the bottom part 36 of the hole in the part 8"'. The outer periphery 35 of the part 7 "', formed by knurling, is fitted by pressing into the lower part 36 of the hole in the part 8"'. During operation, when the screw is fixed and elongates, the outer rim 35 formed by knurling is compressed, but nevertheless enough friction remains to allow upward movement of the 7 "" relative to the 8 "" part without rotating.

In the embodiment shown in Figure 6, the washer is marked with the reference number V "and has a body of 2" ". The body 2 "" washer 1 "" has a first upper face 3 "" adapted to work with the nut, a second lower face 4 "" adapted to work with the object, and has an anti-rotation surface marked with the reference number 5 "" The anti-rotation surface 5 "" is located radially internally and is formed for engaging with the screw thread by wedging on it, for example as, made on the anti-rotation surface 5 "" thread 6 "" corresponding to the screw thread. The body 2 "" washer 1 "" is composed of two parts, 1 "" and 8 "", arranged radially, in fact one adjacent to the other, so that the part 7 "" is placed radially inwardly in part 8 "". The anti-rotation surface 5 '"' with 6" "thread is arranged radially inwardly in part 7" ".

In the embodiment shown in Figure 6, the outer diameter of the surface 37 of the part 7 "" and the diameter of the inner surface 38 in the hole in the part 8 "" are selected such that the inner surface 38 of the hole in the part 8 "" is placed on the outer surface 37 of part 7 "" by pressing it, retaining the interference fit. The injection-molded surfaces, 37 and 38, create local resistance to the washer. The interference fit clamp is selected so that after the screw is immobilized and after further axial force is applied and the screw extends 12, the resistance of the interference fit, surfaces 37 and 38, can be overcome, and the part "Τ" can slide axially relative to part 8 "".

ΕΡ 1 577 569 Bl

In the forms shown in Figures 3 to 6, as in the form shown in the Figure

1, thick front surface, body 22 2 ", 2" ', 2 "backing 12 12", 1 "" 1 "", different friction characteristics with a lower friction coefficient, while the lower face of the washer body aa friction characteristics with a higher coefficient friction, which can be obtained in the same manner as described in connection with the embodiment shown in Figure 1.

It will be understood that each of the elements described above, taken into account separately or assembled together of two or more, may also find useful application in other types of structures that differ from the types of structures described above.

Although the invention has been illustrated and described as including a washer and a coupler equipped with this washer, this should not be regarded as an intended restriction on only the details presented, since modifications and structural changes can in any case be made without departing from the scope of the present invention as defined in the appended claims .