Vibration Free Diamond Polishing Workbench

The cutting or polishing of diamonds and similar stones is usually accomplished at workbenches to which a spindle carrying a horizontal or flat wheel or lap has been mounted. A suitable polishing agent, such as a mixture of diamond dust and oil, is placed on the wheel and the stone to be cut is brought into contact therewith. The wheels are necessarily run at very high speeds, for example, in the neighborhood of 3,000 RPM.

In order to properly effect the cutting and polishing of the stone and avoid interrupted cutting or polishing which can cause damage to the diamond and tremendously decrease the commercial value of the stone, it is necessary that the work table and wheel run perfectly true and with minimal vibration. Various methods of constructing the wheel and spindle and mounting it to a bracket held by the working surface of the work bench have been developed, one of which is shown in U.S. Pat. No. 1,374,267. However, because of the means by which the wheel must be held by the work bench and because of the very high speeds at which the wheels are run, a significant degree of vibration is imparted from the wheel to the work surface making the proper cutting or polishing difficult and dangerous. The difficulty is further aggrevated by the means by which the stone to be cut is brought in contact with the wheel surface. The stone is usually held in a stone holder or dop which is generally a U-shaped object having tongs at one end for holding the stone. The other end of the dop is rested on the work surface and the tong end is pivoted to bring the stone in contact with the wheel. Since the dop is not connected to the work surface, a "bouncing" motion is then imparted from the vibration of the work surface to the dop.

Various designs have been employed in the past to reduce the vibration of the work surface. For example, rubber bushings have been inserted to separate the work surface from the spindle. While such designs have reduced the degree of vibration, they have not been successful in substantially freeing the work surface of vibration.

Accordingly, it is the object of this invention to provide a diamond polishing work bench which has a top working surface on which the dop is rested which is substantially free of vibration.

This and other objects of the invention will become apparent to those skilled in the art from the following detailed description in which

FIG. 1 is a cross sectional view of the workbench of the instant invention, and

FIG. 2 is a top view of the workbench with the second table, wheel and spindle removed.

This invention relates to a diamond polishing workbench whose top surface is substantially free of vibration. More particularly, it relates to a diamond polishing workbench having a substantially vibration-free top table surface in which the table carrying the spindle is isolated from the frame of the bench by first vibration damping means, and the top working table is also isolated from the frame by second vibration damping means and the spindle carrying table and top working table are consequently isolated from each other.

The workbench of the present invention has a frame 1 which is constructed of connected lateral members 2 which have a common upper surface 3, a common lower surface 4, interior surfaces 5 and outer surfaces 6. Frame 1 can be of any desired shape but is generally rectangular. Frame 1 has a plurality of legs 7, preferably one at each corner, extending downwardly from lower surface 4. Frame 1 and legs 7 can be constructed from any suitable material but are preferably steel and are also preferably of unitary construction. It is also preferred to provide suitable braces 8 between adjacent legs. Leveling screws 9 are provided at the bottom of each leg 7.

The interior surface 5 of each of the lateral members 2 is provided with a step 10 of predetermined height in order to define an interior ledge or shoulder. A first table 11 is seated on ledge 10 and separated therefrom by a means 12 to dampen vibration. Table 11 can be held in place by the force of gravity, or by a suitable bolt arrangement which does not transfer vibration energy from frame 1 to the table 11. Means 12 can be any suitable material which absorbs vibration such as rubber, cork, polyurethane foam, etc. While means 12 can be provided between all of the facing surfaces of ledge 10 and first table 11, it has been found sufficient to utilize four pads of vibration absorbing material at the four corners of first surface 11. However, in order to achieve the substantially vibration free top working surface which is the object of the present invention, it is necessary that first table 11 does not come into contact with frame 1 except through means 12. In other words, first table 11 cannot touch or be bolted to frame 1. If desired, table 11 can be replaced by a cross-frame member connected to the ledges 10 through vibration absorbing pads.

A top working table 13 of the workbench is seated on the upper surfaces 3 of lateral walls 2 and is separated from upper surfaces 3 by means to dampen vibration 12 in a similar manner as first surface 11 is separated from ledge 10. Table 13 is held in place by the force of gravity. Again, pads of vibration absorbing material at the corners has been found sufficient to accomplish the purposes of this invention and it is not necessary to have all facing surfaces between working surface 12 and frame 1 connected by means 12. It is, however, necessary that top table 13 neither touch nor be bolted to frame 1. It is also necessary that top table 13 and first table 11 do not come into contact with each other. This can be conveniently accomplished by making the thickness of first table 11 less than the height of step 10.

A bracket means 14 which is adapted to hold a spindle is mounted to the bottom of first table 11 by any suitable means such as bolts 15. Aligned apertures 16, 17, usually circular, are provided in first table 11 and top table 13, respectively, usually at the center thereof to permit passage of the spindle therethrough. A spindle 18 is held in bracket 14 and passes upwardly through aligned apertures 16 and 17 beyond the top of working table 13. A horizontal polishing wheel 19 is mounted on spindle 18 and held in place by any suitable means such as cap 20 such that the bottom of wheel 19 is just above and out of contact with the top of top table 13.

In operation, vibration is imparted to first table 11 by wheel 19 through spindle 18 and bracket 14. However, most of the vibration is not translated to frame 1 because it is absorbed in the means 12 to dampen vibration between first surface 11 and frame 1. The vibration which is translated to frame 1 is not then translated to working table 13 because it is absorbed in the means 12 to dampen vibration between frame 1 and top surface 13. As a result, a dop 21 can be placed on a steady and substantially vibration-free working surface 13.

Various changes and modifications can be made in this invention without departing from the spirit and scope thereof. The various embodiments disclosed herein were for the purpose of further illustrating this invention but were not intended to limit it.