Chuck (engineering)#Special Direct System .28SDS.29

The term refers to a SDS drill shank system for percussive and rotary power tools such as drills and rotary hammers. In this inserting the drill shank is provided with special grooves that ensure a better power transmission. In contrast to other inserting systems of SDS drill shank allows tool-free and quick change of drill bits and chisels.

The abbreviation SDS has several meanings. Originally the system was developed under the name insertion-rotation seat of Bosch and developed later under the name Clamping by system. Today, Bosch used at the international level the term Special Direct System.

Formation

With the widespread use of electric drills and rotary hammers in the 1960s, manufacturers developed different, not mutually compatible, drill shaft systems and tool holders. So Hilti introduced in 1967 a 10-mm light machine for inserting, the Hilti TE - recording. In 1975, the company Robert Bosch, the " SDS- plus" developed from said inserter with a uniform shaft diameter of 10 mm. An advantage of this development was that the SDS-plus drill bits fit in the TE receiving the Hilti machines.

Technology

In Hilti TE recording was engaging rollers ( instead of the spheres) also causes the torque transmission by means of the shallow grooves ( with semi-circular cross-section), the only limit the axial movement on SDS. The weakness of the TE - drill was the wear on the edges of these grooves extremely stressed, what is there in extreme cases, material accumulations ( dross ) led, so that the tools sometimes stalled in the recording.

The drill locking and the torque transmission (² with 60 mm bearing surface ) are decoupled in SDS and are almost free. The drill locking is effected by means of two opposite grooves ( semi-circular cross-section), in which each engages in an integrated cud. On the other hand, the torque is transmitted through two slots to the end, an interlocking manner in the feed to the beam-like projections ( ridges ). Upon axial movement of the drill, the ball rolls and the protuberances slide in said grooves. During the hammer drilling only a small part of the total of 13 millimeters amount longitudinal game is mostly used.

Variants SDS -max and SDS -quick

Patents for SDS-plus have expired, so the offer is no longer limited to the provider Bosch. Technical developments of the patented recording are not on the market, however, variants with smaller and larger shaft diameter. These variants are not interchangeable.