The present invention relates generally to an improved design and construction of fixed weight dumbbell assembly for use in fitness training wherein the assembly process is made simple and conducive to user safety.
Dumbbells are commonly found in fitness centers and gyms, as well as for sale to private users. Typically, two weight-heads are attached to the two ends of a handle bar, forming a fixed weight dumbbell.
Oftentimes, the mechanism for attaching the two weight-heads to the handle bar is by welding, since most handle bar and weight head materials are made of iron. The problem with welding is that because metals absorb heat, by its nature, points of “cold weld” often form on the junction and is a part of latent defect that may cause breakage during later usage. This type of inherent weakness due to the “cold weld” is hard to detect at a reasonable cost.
Another commonly used attaching means is by using lock nuts or screws to fit weight heads to the handle. Although there is no inherent weakness, the nuts or screws inevitably become loose, during the useful lifetime of the dumbbell and needs constant checkup to make sure the weigh heads are not loose, posing dangers to unwitting users.
Present invention introduces a cost-effective construction of a fixed weight dumbbell assembly that provides secured assembly and heightened safety for long-term usage.
Present invention essentially employs two locking pins to guide and secure the assembly of weight heads to a handle bar, enabling easy and secured assembly, while reducing the possibility that the weight heads might become loose even after repeated use of knocking around in a less-than-tended-to settings such as fitness centers or gyms.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the preferred embodiments of the invention and together with the description, serve to explain the principles of the invention.
A brief description of the drawings is as follows:
In
Spring 102 is so situated in the hole to provide resilience force for spring pin 102 to move in radial direction of the handle bar 100's axis.
At end of handle bar 100, a lock pin 113 is movably situated in a position hole 103 axially dug in to the cut off end of said handle bar 100.
Said handle bar 100 further has an axial length of drilled opening from each cut-off end containing thread lines on the inside wall.
On weight head 200, a ring of shoulder 250 is formed in its center through bore. Said shoulder 250 divides the center through bore into a first side and a second side. Said first side is to snuggly receive said handle bar 100. Said second side is to receive a washer piece 210 and a lock nut 220.
A locking hole 203 is drilled through shoulder 250, having same diameter as that of lock pin 113.
A groove AA 201 is formed around the inside wall of weight head 200 center bore, at proper distance from the shoulder 205. This is the same distance as from the edge of said handle bar 100 to the point of said spring pin 101. This is because, when handle bar 100 is inserted into weight head 200, said spring pin 101 will pop in, thanks to the resilience of said spring 102, into groove AA 201, which is machined to snuggly receive spring pin 101.
A locking hole 203 is formed through shoulder 205, so that it is lined up with position hole 103, allowing lock pin 113 to fit through locking hole 203 and into position hole 103.
It can been seen clearly that when handle bar 100 is pushed into the first side of center bore of weight head 200, with handle bar's cut-off end touching and being flush with shoulder 250, spring 102 will push spring pin 101 into groove AA 201, easily and securely attaching handle bar 100 to the weight head 200.
By lining up the position hole 103 and locking hole 203, via the use of lock pin 113, handle bar 100 won't turn or spin relative to weight head 200.
A cap piece 300 has a ring of lip 305 on the outside surface of its cylindrical base 309. The diameter of said cylindrical base 309 fits the second side of center bore of said weight head 200. A ring of groove BB 205 is formed on the inside wall of said second side of center bore to snuggly receive said ring of lip 305.
The edge of cap piece 300 is formed to have angled edge 307. At the end of center bore on the weight head 200, a ring of angled groove CC 207 is made to fit angled edge 307.