RAPID POSSITIONING & CLAMPING SYSTEM (RPCS)

Technical Field

This patent is design to be improvement in construction of milling machines and EDM machines. It can also be used as separate auxiliary fixture that can be mounted on machine table.

The producers in mechanical production, except high volume serial production, are facing the great production time lost on preparation of the work peace for milling.

That problem occurs on milling machines (hi-speed machines, CNC machines as well) and EDM machines. In Tool & Mould production the lost of production time, spent on preparation is about 20%. Unlike on milling machines, turning machines are more efficient (only 1% is lost on preparations).

Background Art

All machine producers are making machine tables with T slots, witch are used with auxiliary equipment for clamping of work peace on table. For this it is necessary to use a number of elements (T-nuts, long screws, clamping bars, shouldering elements, nuts, washers...), witch has to be supplied to every machine.

Beside that we can find different types of clamping systems (mechanical, hydraulic, pneumatic, magnetic), always design as additional equipment with more or less special use.

Disclosure of the Invention

RPCS is system that allows great reduction of the time needed for clamping, positioning and measuring of the work peace before milling. It is design for general purpose of clamping as part of machine.

The most important parts of the whole system are clamps Gogs). Screws simultaneously drive them and they are positioning work peace in ideal position in the middle of the machine table. In the same time, work peace does not need to be precise. It can be even trapezoid or rhomboid and that will not affect precision of the clamping. Clamps are adjustable on work peace for angle B. That is also important for transmission of the clamping force on work peace. All of that allows clamping of the raw material with minimal costs.

After positioning of the work peace, hydraulic system lifts all clamps. They are rotating over spherical nut for clamping angle α, simultaneously clamping the work peace witch is remaining in position. The vertical component of the clamping force is pushing the work peace down on table. That gave us additional stability of the work peace in position for milling.

By rotation α upper surface of the clamp is pressed on lower surface of the table, and friction between them prevents any movement of the work peace caused by vibrations during milling process. The screws and spherical nuts does not suffers any clamping force witch is crucial for precision and long lasting of the system.

The RPCS makes possible:

Positioning of the work peace in the middle of the machine table, Not to measure parallelism and position of the work peace, To mill even rough materials, To mill top and side of the work peace with no interruption.

Attached drawings

Fig.1 Isometric view of the machine table with RPCS

Fig.2 Top view of the clamping with RPCS

Fig.3 Section view of the clamping with RPCS

Fig.4 Isometric view of the RPCS clamp (jog)

Fig.5 Isometric view of the spherical nut

Fig.6 Section detail view with explains working of the RPCS

Detail explanation of the RPCS

Driving mechanism (Pos.3) over transmission simultaneously drive screw (Pos.4). Every pare of clamps (Pos.5) is driven simultaneously and they are moving work peace (Pos.2) in the center of the machine table (Pos.1). Every clam adjusts itself on work peace by rotation around center (C) for angle β. That's why there is no need for measuring position of the work peace before milling.

The RPCS Clamp is assembly consisting of: Body of the clamp (Pos.5.1) Clamping plate (Pos.5.2) - Cover of the nut (Pos.5.3) Spherical nut (Pos.5.4) Hydraulic spring (Pos.5.5)

The work peace clamping starts after it came in the center of the machine table, by switching the valve of the hydraulic system. The pressure of the oil moves hydraulic spring (Pos.5.5). It is mounted on clamp body (Pos.5.1) and lifting the clamp in clamping position rotating around center (C) for clamping angle a. Rotation is possible because of unique spherical nut (Pos.5.4), witch holds still suffering no clamping force.

Hydraulic clamping force Fc is multiplied caused by different moment arm of the force F and Fc. Clamping force is applied on work peace over clamping plate (Pos.5.2). The body of the clamp has two upper (RzIOO) friction surfaces, witch are pressed on lower surface of the table (Pos.1), producing friction-holding force Ft. That force relieves driving mechanism of any clamping force.

Possible implementation of the RPCS

RPCS has been designed to be part of the machine table as improvement in construction of the milling machines and EDM machines. Also the RPCS can be designed as additional fixture on exiting machines.