| AU5065579A | 1980-03-20 | |||
| EP0851129A1 | 1998-07-01 | |||
| JP2000027835A | 2000-01-25 | |||
| DE3617339A1 | 1987-11-26 | |||
| DE4439567A1 | 1995-06-22 | |||
| GB1536598A | 1978-12-20 |
| 1. | A cap for bolts and screws with heads, and nuts, where the head or nut projects perpendicular from the surface the fastening device it belongs to penetrates, comprising a body and a recess in the bottom surface to be press fitted after the device has been fastened. |
| 2. | The cap of claim 1 where the shape of the body is appearance enhancing. |
| 3. | The cap of claim 1 where the shape of the body is security enhancing. |
| 4. | The cap of claim 1 where the shape of the body is appearance and security enhancing. |
| 5. | The cap of claims 1 to 4 where the material of the body is passive corrosion protection. |
| 6. | The cap of claims 1 to 4 where the material of the body is active corrosion protection. |
| 7. | The cap of claims 1 to 6 where the press fit is achieved by accurate dimensions of the recess. |
| 8. | The cap of claims 1 to 6 where the press fit is achieved by oversizing the recess and provision of vertical and/or horizontal ribbing on the walls of the recess that draws away when the cap is pressed on. |
| 9. | The cap of claims 1 to 6 where the press fit is achieved by any other means. |
"The subjects"are a very common and therefore cheap method of assembling and fastening objects and structures, but they have some shortcomings. They can be very detrimental to the appearance of the object or structure, they can be easily undone with common tools, and therefore provide no security, and they can be susceptible to corrosion, even if treated, e. g. zinc plated, through damage to the protective coating in the process of applying them.
These problems are overcome by this invention, which provides a cap for"the subjects"comprising a body and a recess in the bottom surface to be press fitted after the device has been fastened The cap may be made from any suitable material, such as metal or plastic.
The different problems, appearance, security, corrosion, may be attended to either separately or in any combination thereof.
For appearance related applications, the body may be made to any shape or design to accomplish the desired appearance, such as a forged rivet head or a rosette.
For security related applications, the body may be made to any shape that is very inaccessible to common tools like spanners, pliers, screwdrivers etc, such as a dome that fits flush to the surface the fastening device penetrates, and therefore can neither be easily gripped, rotated or levered of.
For anti corrosive applications, all caps provide a certain amount simply by protecting "the subjects"from the elements, passive protection, but for additional protection the cap may be made from an anti corrosive material, such as zinc, which induces a galvanic process that not only protects"the subjects"but surrounding ferrous metals as well, active protection.
For any combination thereof the shape and the material of the body may be chosen appropriately.
The press fit can be achieved by different means, e. g. accurate dimensioning of the recess or oversizing the recess and provision of vertical and/or horizontal ribbing on the walls of the recess, that draws away when the cap is pressed on.
To assist with understanding the invention, references will now be made to the accompanying drawings, which show two examples of the invention.
In the drawings: FIG. 1 shows one example of a cap according to this invention in technical drawing, top perspective.
FIG. 2 shows same example of a cap according to this invention in real view, bottom perspective.
FIG. 3 and FIG. 3a show the application of two such a caps to a bolt and nut assembly of two pieces of flat material.
FIG. 4 and FIG. 4a show another example of a cap according to this invention in real view perspective and side elevation.
Referring to FIG. 1 and FIG. 2, it can be seen that the cap according to this invention comprises a body 1 and a recess 2 in the bottom surface 3. In this example the body 1 is dome shaped for good appearance and very good security properties, with common tools the cap can neither be easily gripped, rotated or levered of. The anti corrosive properties can vary from fair to very good, depending on the material of the body. The recess 2 in the bottom of the surface 3 is accurately dimensioned hexagonal, to be press fitted to a hexagonal bolt head, screw head or nut, and deep enough for the body to fit flush with the surface the fastening device penetrates.
FIG. 3 and FIG. 3a show two such caps in operation. Two pieces of flat material 6 and 7 are assembled by a bolt with hexagonal head 4 and a hexagonal nut 5. The two caps comprising the body 1, and the recess 2, accurately dimensioned hexagonal, in the bottom surface 3, are in position to be press fitted, FIG. 3, and after being press fitted, FIG. 3a.
FIG. 4 and FIG. 4a show a different cap according to this invention, a hexagonal forged rivet head, which has very good appearance, low security, and depending on the material used for the body, fair to very good anti corrosive properties.
By the use of such caps, the performance of"the subjects", such as machine bolts and nuts, coachscrews, screwbolts, can be enhanced in matters of appearance, security and corrosion protection, either separately or in any combination thereof, where ever an object or a structure is assembled or fastened with"the subjects", such as buildings, bridges, balustrades, window grills, gates, furniture.
It will be realised that the cap according to this invention is not restricted to the body shapes, recess shape or press fitting method shown in these examples, but may be made to any body shape to accomplish the desired appearance and/or security properties, to a recess shape of any of"the subjects"to be press fitted by any method, and may be made from any suitable material to accomplish the desired anti corrosive properties.