US 4,903,785 AGranted

Drilling and chiseling tool bit

AssigneeHilti Aktiengesellschaft

InventorsWalter Odoni, Oliver Berchtold, Wilhelm Gerber

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Abstract

A drilling and chiseling tool bit includes a tool bit head, an axially extending shank and an insertion end for insertion into a drilling or chiseling device. The shank extends between the tool bit head and the insertion end and is divided into individual axially aligned members. The individual shank members are held together by a retaining member which also interconnects the tool bit head and the insertion end. The tool bit head and insertion end are rotatable as a unit and are movable axially relative to one another. By dividing the shank axially, its individual members have a higher natural frequency and afford improved transmission of impact energy. As a result, preventing the excitation of natural vibrations in individual shank members, the vibration period is shorter compared to the impact transmission time period. Accordingly, the sound radiation from the tool bit is reduced.

Claims9

Dependent claims

A drilling and chiseling tool bit for working in concrete, rock, masonry and the like, comprising an axially elongated shank having a first end and a second end spaced apart in the axial direction, a tool bit head at the first end of said shank and an insertion end at the second end of said shank for insertion into a drilling or chiseling device, said insertion end includes means for rotational entrainment with the drilling or chiseling device, wherein the improvement comprises that said shank is divided into a plurality of axially aligned separate individual shank members of similar length and shape, said tool bit head and said insertion end are separate from said shank, the mass of each of said shank members, said tool bit head and said insertion end is approximately the same, and means separate from said shank for interconnecting said tool bit head and said insertion end so that said head and end are rotationally connected together and are axially movable relative to one another, said interconnecting means for connecting said tool bit head and insertion end comprises means for transmitting torque from said insertion end to said tool bit head and axial stop means cooperating with corresponding means at said tool bit head and insertion end.

Dependencies are inferred from the claim text.