Patent Application
20120054999
The present invention relates to a fabrication method and particularly to a fabrication method capable of detecting fabrication defects of sleeves for trampolines.
Trampoline is a jumping sport equipment allowing users to jump in the air to perform various movements to do exercise on leg muscles, enhance bouncing capability and improve coordination. Besides used on general sport activities, it is also frequently used in circus or acrobatics to allow performers to do special movements in the air to entertain audiences.
U.S. patent Nos. 2004/0176214, 2006/0172861 and 2007/0012902 disclose trampolines that include a frame to hold a jumping net. The frame consists of a plurality of tubes coupling together in a compact manner. The tubes usually are fabricated by machining a tube close to an opening in a conical shape at a reduced outer diameter or in a cylindrical shape at an outer diameter smaller than the tube so that mutual coupling can be accomplished between them. The tube generally is made of metal and can be formed integrally such as by casting, injection or machining. It also can be fabricated from a metal plate by forming and bonding. The tube made integrally generally is more expensive, but is cheaper if fabricated from the metal plate, thus the metal plate is commonly adopted to reduce production cost.
Please refer to
During assembly of the trampoline, the solder seam 3 has to be inspected whether obvious detects are formed before the first tube 1 and second tube 2 are coupled with each other to avert defective coupling between the first tube 1 and second tube 2. As possible defects on the solder seam 3 are very small and usually cannot be detected by visual inspection, the conventional inspection method is aided by incorporating with inspection equipment to project light on the solder seam 3. By observing through the light penetration, a defect can be identified. However, such a method cannot be applied to mass production if a great number of tubes have to be inspected and significantly reduces assembly efficiency of the trampoline. As a result, production cost is higher.
Therefore, the primary object of the present invention is to solve the problem of tube inspection of the conventional trampoline that requires extra equipment to determine coupling quality.
To achieve the foregoing object, the present invention provides a method of fabricating sleeves for trampolines that forms a frame of a trampoline. The method includes the steps as follow:
bending a plate which has a first lateral edge and a second lateral edge that face each other to form a coupling seam which is bonded through a bonding process to form a sleeve;
expanding an opening of the sleeve through an opening expansion means so that the sleeve includes a body and an expanded opening section extended from the body and formed at a diameter greater than that of the body;
applying a compressive force to the expanded opening section to form an outer expanded portion connected to the body and an inner folding portion bending inwards; and
inspecting visually the coupling state of the coupling seam in the outer expanded portion and the inner folding portion to determine whether the first lateral edge and second lateral edge are bonded tightly.
The fabrication method of the sleeves set forth above provides many advantages over the conventional techniques, notably:
1. The outer expanded portion and inner folding portion reinforce structural strength after the sleeves are coupled, and can withstand greater impact of external forces without causing damage on the coupling seam.
2. Defected products caused by defective coupling seam can be visually detected when the compressive force is applied to the expanded opening section without the aid of extra inspection equipment, hence productivity of fabricating the trampoline increases.
3. The method of fabricating sleeves of the invention integrates the fabrication process of sleeves and inspection of the coupling seam so that fabrication and defect inspection of the sleeves can be performed at the same time to reduce process steps of trampoline production.
The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.
Please refer to
forming a sleeve (S10) by bending a plate which has a first lateral edge and a second lateral edge that face each other to form a coupling seam, then bonding the coupling seam through a bonding process to form the sleeve;
expanding an opening of the sleeve (S20) through an opening expansion means so that the sleeve includes a body and an expanded opening section extended from the body and formed at a diameter greater than that of the body;
bending the sleeve (S30) by applying a compressive force to the expanded opening section to form an outer expanded portion connected to the body and an inner folding portion bending inwards; and
inspecting the coupling state of the sleeve (S40) through a visual inspection means to inspect the coupling state of the coupling seam in the outer expanded portion and inner folding portion to determine whether the first lateral edge and the second lateral edge are bonded tightly.
The fabrication method previously discussed is further elaborated through embodiments as follow:
Referring to
Refer to
The sleeve 20 of the invention can be formed in varying profiles.
After the fabrication process of the sleeve 20 is finished, the coupling state of the coupling seam 21 in the outer expanded portion 241 and inner folding portion 242 can be inspected visually to determine whether the first lateral edge 11 and second lateral edge 12 are tightly bonded, and defects of the coupling seam 21 can also be detected visually through naked eyes, or through an image capturing device by capturing the image of the coupling seam 21, then operators can determine whether defects existed on the coupling seam 21 by examining the image. In practice, if no defect is seen on the coupling seam 21, the sleeve 20 can be judged acceptable for assembly in the following process as shown in
Referring to
As a conclusion, the method of fabricating sleeves for trampolines of the invention mainly aims to expand the opening of the sleeve and bend the opening before assembly of the sleeve and connection tube. Defects on the coupling seam can grow to a size visible by naked eyes. Hence operators can easily and visually detect defected products or acceptable products. On production lines, workers can instantly identify defected products through a simple fabrication process without sending the sleeves to other inspection equipment to do inspection before conveying to the following process. Thus assembly time of the trampoline can be reduced and production cost also is lower, and productivity can be enhanced. The outer expanded portion and inner folding portion also increase the structural strength after the sleeve and connection tube are coupled together.
While the preferred embodiments of the invention have been set forth for the purpose of disclosure, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.
