Patent Application
20200263305
This disclosure is directed to a U-bolt and to a metal rod useful in forming a U-bolt. This disclosure is also directed to a method for producing a metal rod and/or U-bolt having an anticorrosive coating.
U-bolts are used in a wide range of applications. In the automotive industry, U-bolts can be used to securing truck and trailer suspensions, springs, and for other uses. U-bolts are typically available in a range of sizes and in a variety of steels and finishes. Suppliers such as L & H Threaded Rods Corporation provide unbent threaded rods in various lengths and diameters which purchasers can bend around a die of a bending machine to form a U-bolt. For example, L & H currently sells rods in diameters ranging from ⅜ inch to 1¼ inch in ⅛ inch increments, and in lengths ranging from 10 inch to 48 inch in 2 inch increments.
U-bolt manufacturers usually place the unbent rods in a supply rack where they are sorted by length and diameter. One problem can occur when the rods are misplaced in the supply rack and the wrong length rod is selected for bending. Another problem can occur because the rods are often coated with a thin coating of an oil to prevent corrosion, or oil can drip on the rods during manufacture or storage. When the rods are removed from the storage rack and positioned on the bending machine, the oil can rub off on the hands and gloves of the worker. Oil on the rods can also taint the container in which the rods are stored or shipped. For example, if the container is made of packaging board, the oil can weaken the packaging board and enable it to tear prematurely. In addition, existing rods may not be sufficiently corrosion-resistant.
In one embodiment, the invention is a system including a rod shaped and configured to be formed into a U-bolt, the rod including a body having a pair of opposed threaded ends. The system further includes a blackening coating on an outer surface of the body, and an anticorrosive coating on the blackening coating.
As shown in
As shown in
The rod 10/body 12 can be made of metal or other ferrous materials, including low carbon steels, medium carbon steels or high carbon steels. Any rod 10/body 12 used in forming a U-bolts 16 by bending around a U-bolt die can be useful in practicing this disclosure. Appropriate rods 10 are commercially available from L&H Threaded Rods Corp. of Moraine, Ohio, and include high quality medium carbon 1541 Grade 5, high carbon Grade 8 and lower carbon 1018's, 1020's and 1040's.
The U-bolt 16 can be used in various applications, including in one case by attaching components to the undercarriage of an automobile chassis or frame, or other components. In the embodiment of
The rod 10 of
One example of a process for treating the rod 10/U-bolt 16 is shown schematically in
From the first treatment station 34 the rods 10 are transported, such as by being carried on the conveyor 32, to and through a blackening station 36 including in one case a vat of a blackening solution 40. The conveyor 32 can be positioned in or extend through the vat of blackening solution 40 so that the rods 10 are, in one case, immersed in the blackening solution 40 as they travel through the vat. The vat and conveyor 32 can be designed and operated so that the rods 10 are exposed to the blackening solution 40 for sufficient time (e.g. at least one minute in one case, and less than ten minutes in another case) that the rods 10 are adequately blackened as they travel through the blackening station 36. The solution of the blackening agent 40 may be a black oxide former such as a solution including copper sulphate and selenious acid. One example of a copper selenide solution is described below, but blackening agents than copper selenide can be used.
One specific example of a cold black oxide former that can be used for blackening contains about 60-70% water, about 10-15% selenious acid, about 3-6% copper (II) sulfate penthydrate, about 4-8% phosphoric acid, and about 3-6% nitric acid. This solution can be used or applied at approximately ambient temperature, e.g., between about 60° F. and about 100° F. In one process, the black oxide coating is obtained by immersing the rod 10 in the blackening solution for about 1-5 minutes. Additional treatment for blackening is generally not required. The black oxide coating can be applied/formed without materially affecting the diameter or thickness of the rod 10, as the coating can have a thickness than is less than about 2 microns, and does not adversely affect the ability of the threaded ends 14 to accept a threaded nut 22. The black oxide coating, and the chemicals associated with such treatment, can convert a surface layer of the rod 10 to and/or form coating of a formed/deposited copper selenium compound such as but not limited to copper selenide or CuSe or Cu2Se.
As an alternative to applying the cold black oxide coating described above, it also within the scope of this disclosure to have the black oxide coatings applied/formed by hot oxide processes, instead of cold forming. However, hot black oxide processes may be less desirable in this application due to the heat involved and the nature of the reagents used. After the hot blackening process is complete, a magnetite (Fe3O4) coating is formed on the outer surface of the rod 10.
From the blackening station 36, the rods 10 are carried to a rinse station 42 which contains a vat of a rinse solution 44, such as water or an aqueous solution, in which the rods 10 are immersed as they travel through the station 42. The rinse solution 44 stops the blackening process. After the rods 10 have been blackened and rinsed as described above, the rods 10 can be transported on the conveyor 32 to a station 46 where they are coated with an anticorrosive sealant or coating. The blackening process/coating provides a porous or textured surface on the rod 10 that is particularly suitable for securely bonding the anticorrosive coating to the rod 10, but does not adversely affect the ability of threaded ends 14 to accept a threaded nut 22. The porous crystalline structure of the black finish of the rods 10 makes it an excellent absorbent base for an anticorrosive coating. Corrosion resistance can be accomplished using a variety of anticorrosive coatings provided the coatings bind to the black oxide coating as described herein. In one particular embodiment the anticorrosive coating is an acrylic polymer or an acrylic lacquer that is applied to the black oxide surface and then dried. After drying the rod 10 can present a continuous black surface about all outer/exposed surfaces that is dry to the touch. The anticorrosive coating may be generally clear or transparent, or sufficiently translucent, particular when applied as a film, that the rods 10 appear black even after application of the anticorrosive coating. After the rods 10 are formed, a label that identifies the diameter and/or length of the rod 10 can be coupled to the rod 10.
In combination, the blackened outer surface of the rods 10 and the anticorrosive coating provide the rod 10 with a strong dry, non-oily and non-tacky barrier to corrosion. Without blackening the rod 10, the anticorrosive layer would be prone to be removed or scratched off of the rod 10 during bending or installation of the U-bolt, or in use in the field. On the blackened surface, the anticorrosive coating imparts anticorrosive properties and a dry touch to the rod 10 thereby making the rod 10 more convenient to handle and more industrially and commercially desirable. In addition, the undercarriage of many automobiles is of a black color. By providing rods 10 that are of a black color, and also corrosive resistant, the rods 10/U-bolts 16 can naturally blend in with the rest of the components on the undercarriage of an automobile.
While the process has been illustrated in
After the rods 10/U-bolt 14 are formed, they can have patches of color applied thereto, such an on the (circular, axial) ends 48 of the threaded ends 14. The color coding can provide useful information to a user as to the length of the rod 10 which can have various discrete lengths. The chart of
Thus in one embodiment the color coding system can use different colors on the ends 48 of the rods 10 to designate rods 10 having differing lengths where the rods 10 differ in length by at least ten inches, or some other predetermined number as desired. In one case the predetermined number is six inches in one case, eight inches in another case, or twelve inches in another case, and in another case is the length of the shortest rod 10 of the set of rods 10 marked according to the color marking scheme. In yet another case the predetermined number is 25% of the longest rod 10 of the set of rods 10 marked according to the color marking scheme. In other words, repeating identifying colors can be used, so long as the rods 10 have a sufficiently different length.
In one embodiment the color coding system can use the same colors on the ends 48 of the rods 10 to designate rods having differing lengths where the rods 10 differ in length by at least ten inches, or some other predetermined number as desired as outlined above. Thus the same color can be used to indicate rod lengths that differ by at least ten inches in one case, or other lengths as desired. Although the number of colors used can vary, and the number is five in the illustrated embodiment, in another case the number of differing colors can be at least three. The color identifying scheme can also or instead be used to identify other parameters of the rods 10, such as diameter, material, coating, etc.
Having described the invention in detail and by reference to specific or preferred embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention which is defined in the appended claims.
This application claims priority to U.S. Provisional Patent Application Ser. No. 62/805,378, filed on Feb. 14, 2019, the entire contents of which are hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62805378 | Feb 2019 | US |
