US 12,140,214 B2
Composite gearwheel for an electropneumatic hammer drill
Daniel Seltmann, Landsberg am Lech (DE); and Josef Fuenfer, Koenigsbrunn (DE)
Assigned to Hilti Aktiengesellschaft, Schaan (LI)
Appl. No. 17/613,436
Filed by Hilti Aktiengesellschaft, Schaan (LI)
PCT Filed Jun. 17, 2020, PCT No. PCT/EP2020/066684
§ 371(c)(1), (2) Date Nov. 22, 2021,
PCT Pub. No. WO2020/260081, PCT Pub. Date Dec. 30, 2020.
Claims priority of application No. 19182585 (EP), filed on Jun. 26, 2019.
Prior Publication US 2022/0213953 A1, Jul. 7, 2022
Int. Cl. B25F 5/00 (2006.01); F16H 55/06 (2006.01); F16H 55/12 (2006.01); F16H 55/17 (2006.01)
CPC F16H 55/06 (2013.01) [B25F 5/001 (2013.01); F16H 55/12 (2013.01); F16H 55/17 (2013.01); B23B 2222/84 (2013.01); B23B 2226/27 (2013.01); B23B 2226/61 (2013.01); B23B 2260/07 (2013.01); B25D 2222/06 (2013.01); B25D 2222/42 (2013.01); B25D 2222/54 (2013.01)] 18 Claims
OG exemplary drawing
 
1. An electropneumatic hammer drill comprising:
a composite gearwheel for an electropneumatic hammer drill, the composite gearwheel including:
a basic body consisting of a first material; and
a toothed body consisting of a second material different from the first material;
the composite gearwheel having an encircling toothing formed, along a first circular arc, by the toothed body, and formed, along a remaining second circular arc by the basic body;
wherein the composite gearwheel is installed in a transmission unit of the hammer drill in such a way that only the part of the encircling toothing formed by the toothed body is exposed to an increased torque of an impact mechanism of the hammer drill.