LOCKING DEVICE SUCH AS A LOCK WASHER; SECURING PLATE AND THE LIKE

Abstract: A locking device or fastener as a lock washer, securing plate or similar, made in one piece, preferably of metal, which is designed to arrest, lock or prevent displacement, twisting or rotation of the device itself and/or between assembled machine or building components such as screws, nuts, axels, plates and hubs (2-5). The locking or arresting mechanism is formed by staves, hooks or locking dogs (8), almost completely or partially freed from the surrounding material, whose angle of orientation is such that they are turned by the frictional drag of the elements pressed against them without slipping. In this way, due to their movement geometry, the thickness of the locking members, or their projection beyond adjacent material surfaces, will be increased. Because of this effect, successively increased forces will bear upon the surfaces of the assembled components and, where present, the nut thread and bold holding them together, which will prevent any further displacement of any of the integrated elements.

Description: LOCKING DEVICE SUCH AS A LOCK WASHER; SECURING PLATE AND THE LIKE. The present invention relates to a locking device of the same type as lock washers, clamping sleeves and anchoring plugs, for arresting, locking and securing against un¬ desirable positional displacement, twisting or rotation in screw and bolt joints, no-slip and mechanical joints etc. within, for example machine-building, caused by vibration or shaking or the effects of other external forces. With screw joints and no-slip joints there is usually the primary requirement that there is built in to the joint a high resistance to displacement or loosening of its components, especially in connection with stresses from vibrations or static and dynamic forces. A large number of methods and constructions have been developed for this purpose. There is, however, no device which is highly effective in its locking function and, at the same time, rational, reliable and inexpensive in both its manufacture and its handling. The optimum locking device should thus be easy and cheap to manufacture with conventional equip- ment and known techniques, and should, in view of costs, be made from a single piece. Further, it should, at least when in the form of a lock washer, be reversible without losing its function, and also be unaffected by its environ¬ ment and handling. In addition, the locking device should not require any special adaptation with regard to adjacent components, for example, a certain surface structure or the like. Finally, the locking device should, in most cases, be easy to dismount and also allow repeated use. The present invention, the purpose of which is to fulfil the requirements stated above for the ideal locking device, has for this purpose produced a device with characteristics as given in the patent claims. Several design examples of the invention are described below with reference to the appended drawings. Figs.1-16. Fig. la is a plan view of a locking device in accordance with the invention, in the form of a concentric lock washer, which is also shown in cross section and side elevation in Figs, lb and lc respectively. Figs. 2a and 3a are sections of two variants of the locking mechanism itself after clamping between adjacent components, while Figs. 2b and 3b show the locking or arresting mechanism of the lock washer when fully engaged. Figs. 4a and 4b, Fig. 5, Figs. 6a and 6b, Figs. 7a, 7b, 8a and 8b and Figs. 9a-c all show alternative designs of an arresting and locking washer in accordance with the invention. Figs. 10a and 10b show a lock washer with conical bearing surfaces while Fig. 11 shows a lock washer with oblique locking dogs. Figs. 12a and 12b and 13a-c show two straight variants of the locking device in accordance with the invention. Figs. 14a and 14b illustrate a sleeve-shaped locking device based on the concept of the invention. Figs. 15a-e show some alternative cross sections of the locking dogs. Finally, Figs. 16a and 16b illustrate a springing and clamping mechanism, directly connected to the locking device. In each drawing, 1 indicates a locking device in accordance with the invention in its entirety. 2 and 3 (Figs. 2 and 3) are extraneous, attached components or adjacent walls, for example, two metal plates. 4 signifies a screw or bolt head, while 5 is the associated nut. The locking device 1 is, when the invention is applied as a lock washer, a round or angular, holed and substantially flat washer, but can also be a rectangular profile or strip (Figs.12,13) , or consist of a sleeve (Fig. 14) with a locking function upon an axel and mounted hub. A method of production for the locking device can be a shearing and pressing operation from a temperable metal sheet, but it may also be manufactured by, for example, plastic working, cutting or powder pressing. The cavity or centre hole 6,for an axel or bolt with head 4, through a lock washer 1 may be punched and, where required, edged with a rolled up ferrule or collar 7 (Fig.7), which is compressed to a chosen thickness. Upon the forced compression of the collar 7 during mounting, the inner diameter of the centre hole 6 will be reduced to a certain degree, which results in the clamping of the lock washer to the axel or bolt shank. Radially out from the centre hole 6 or collar 7, a number of tabs, staves or locking dogs 8 have been freed from the body of the lock washer by pressing, cutting or punching so that there are spaces 9 between each dog 8 and the circumferentially adjacent members of the lock washer 10, which form distancers 10. The locking dogs 8 are twisted in a suitable direction and to a suitable degree about or against their fastening points, which thus form joints 11 and can be stamped and formed directly out of the base material or metal sheet. The length, breadth, thickness, shape, pretensioning and angle of twist of the locking dogs are determined with regard to the size, thickness and intended use of the lock washer. Similarly, the number and type of distancers 10 and locking dogs 8 is chosen with regard to the other dimensions, purpose and functional environment of the lock washer. In order to increase the pretensioning of and to guide the locking dogs 8, then these may be cut, stamped or arranged so that spring tongues 12 and 13 (Figs. 16a & b) are formed, which press against the distancers 10 or against each other if there are no distancers. The locking dogs 8 are angular in section so that they have diagonally opposite gripping edges 14,15. When the lock washer is clamped between elements 2 and 3 or components 4 and 5, the screwing effect turns the locking dogs 8 to a predetermined position, which is determined by the height or thickness of the distancers 10 or by the distance of the bearing surfaces from each other. The diagonally opposite gripping edges 14 and 15 of the locking dogs 8 are then level with or flush with the facing bearing surfaces and/or both principal planes of the lock washer 1, the major part of the bearing pressure then being distribute along the distancers 10. By a suitable design of the joints 11, locking dogs 8 and spring tongues (where included) 12, 1 (Fig.16a) and by the choice of a lock washer material with a certain springiness, then a certain edge or gripping pressur is obtained upon the gripping edges 14,15 of the locking dog in engagement with the contact surfaces of the assembled components. Should a tendency to counter-rotation or dis¬ placement occur in the lock washer itself or in any of the „ adjacent components 2,3,4,5 in relation -to the others, then each locking dog will turn to a corresponding degree. Becaus of the movement geometry and set angle of friction of the locking dogs, the engagement with the gripping edges will increase and thereby the pressure or force on each component on the screw thread or on the joint in general, and in this way, a no-slip, self-arresting effect is obtained. Further rotation or displacement in relation to adjacent components will consequently be prevented. Safe and reliable functionin is achieved if the frictional drag of the edges 14, 15 of th locking dogs and the initial springing effect of their joints 11 and the spring tongues 12,13 exceed the counter- directed force components which strive to prevent the turning of the locking dogs. The required frictional drag for this turning will be sufficient if the shape and degree of turn of the locking dogs at the starting point form an angle of inclination of the diagonal line between the bearing or gripping edges of the locking dog which is less than the angle of friction of the materials engaged. A further modification of the lock washer is shown in Figs. 10a and 10b, where the locking dogs vary in height or thick¬ ness outwards from the centre hole 6 and towards the periph¬ ery. This, however, requires a corresponding conical form of the contact surface of adjacent components, such as a screw head or nut. This configuration has been chosen so that the locking dogs, when turning, attain the correct speed at ever point along their gripping edges with no partial sliding or lag. Fig. 11 shows a variant of the lock washer where the locking dogs' extension inwards from the uniting outer ring is not strictly radial but slanted, so that attempts at -unscrewing cause the inner ends of the locking dogs to swing inwards towards the centre, and thereby contribute to locking the screw axis. Figs. 12a and 12b, and 13a-c show two further designs of the locking device where a washer, a plate, a straight profile or strip with the above described functions has been -formed from a punched and pressed strip of suitable straightness and shape. To achieve a double-acting effect, in one of the designs (Figs.12a, 12b) each alternate locking dog has been turned so as to acquire an opposite locking direction. In the other design (Figs. 13a-c), the sheet material has been bent double so that the locking dogs 8 occur in opposed pairs, thereby achieving some economic advantages in manufacture ' . Figs. 14a and 14b show a locking device designed as a sleeve or hub, with the locking dogs 8 arranged axially. In other designs the locking dogs may be arranged at other angles, for example, transverse to the axis. By action upon one end of the sleeve, or by the turning of an axel or hub, the locking dogs will be forced to assume a locking position determined by play, frictional drag, shape, force and other factors. Many modifications can otherwise be conceived where the particular locking function in accordance with the invention is made use of within the framework of the concept of the invention. Thus, for example, the cross sectional shape of the locking dogs does not necessarily need to be angular or edged at all, but could, to advantage, be partially circular, elliptical or eccentric. There is a further variant in which the locking dogs in accordance with the invention - instead of being flexibly joined directly in the base material - are baked in soft rubber or plastic between the contact surfaces or mantle in general. It can be advantageous to limit the movement of the locking dogs, either by a stop on the dog itself (Fig. 15d) or by a lip adjacent to it, in that position where the gripping edges 14,15 are at their most extreme or highest points and where they are fully loaded and at maximum penetration of the adjacent material, i.e. where shear resistance and frictional drag are at their most developed. It is also an advantage if the movement geometry of the locking dogs is such that they attain a high degree of lift. One method of achieving this is to arrange two gripping edges, one after the other, on either side of the fulcrum point or rotation centre (Figs. 2a-b, Fig. 15d) . The first pair of gripping edges to engage, 14,15, turn the dog further to a first maximum position, after which the next pair of gripping edges 14b, 15b, which in this position have attained a sufficient frictional drag and purchase, then aid a continued turning and thereby increase the thickness or height of the locking device. An increased locking height function and extended range of use can be achieved by doubling up two locking devices as in Figs. 13a-c. The invention can, in this way, also be applied to anchoring devices in drilled holes or slots in rock strata etc.

Claims: PATENT CLAIMS 1. Locking device like a lock washer, friction plate, clamping sleeve, plug or expander, intended for use in the assembly of machine or building elements etc., and which comprises a flat or sleeve-shaped body with arresting and locking dogs formed from the same base material, c h a r - a c t e r i s e d by the locking dogs (8) being in the form of tabs, staves or dogs (8) freed from the body at least partially throughout its thickness and otherwise joined to the rest of the body by one or more joints (11), wings or arms, and having at least one portion, such as an edge, which projects beyond the side or mantle surface of the body, and by the said joint or joints (11) allowing the staves or locking dogs (8) to turn when under load, and by the said portions of the locking dogs (8) comprising hooking or gripping edges (14,15) which are arranged, preferably,approximately diagonally or directly opposite each other on each side of the mantle or body wall, and by the orientation of the gripping edges (14,15) in the locking or arresting direction being limited, during the clamping or mounting of the locking device, by stops or distancers (10) between the locking dogs (8) or by some other dimensional adaptation so that the angle of a line . between the said gripping edges,or between one gripping edge (14,15) and its load-carrying joint (11), to a line normal to the plane or base surface of the body, is in a certain proportion to the angle of friction of the material .in use. 2. Device in accordance with patent claim 1, c h a r¬ a c t e r i s e d b y the joint or joints (11) having a springing function and being pretensioned upon the locking dogs (8), with the effect that an initial grip upon adjacent material surfaces is achieved when mounting the locking device. 3.. Device in accordance with patent claims 1-2, c h a r a c t e r i s e d b y the locking dogs (8) being provided with tabs or spring tongues (12,13) with a turning effect and/or orientation function. 4. Device in accordance with patent claims 1-3, c h a r a c t e r i s e d b y the locking dogs (8) being provided with extra gripping edges (14b,15b) designed to come into effect when the primary gripping edges (14,15) approach or have attained their most extreme or highest position during the locking process. 5. Device in accordance with patent claims 1-4, c h a r a c t e r i s e d b y the turning movement of the locking dogs during the locking process being limited by edges, shoulders or strips (14b,15b) so that the gripping edges (14,15) are arrested in their highest or most extreme position. 6. Device in accordance with patent claims 1-5, c h a r a c t e r i s e d b y the locking dogs and the portions with gripping edges being arranged so that they form, at the same time, both the arresters and the stops or distancers of the locking device (8,14a-b,15a-b) .

Inventors: BURSTROEM BERTIL, BURSTROEM, BERTIL
Applicants: BURSTROEM BERTIL, BURSTROEM, BERTIL
Application year: 1986
Main classification: F16B39
IPC codes: F16B39