US 12,350,802 B2
Electropneumatic impact mechanism
Ernst-Rudolf Lübkert, Landsberg am Lech (DE); Uto Plank, Freising (DE); and Jochen Erhardt, Klosterlechfeld (DE)
Assigned to Hilti Aktiengesellschaft, Schaan (LI)
Appl. No. 17/916,928
Filed by Hilti Aktiengesellschaft, Schaan (LI)
PCT Filed Apr. 7, 2021, PCT No. PCT/EP2021/059072
§ 371(c)(1), (2) Date Oct. 4, 2022,
PCT Pub. No. WO2021/213804, PCT Pub. Date Oct. 28, 2021.
Claims priority of application No. 20170526 (EP), filed on Apr. 21, 2020.
Prior Publication US 2023/0150103 A1, May 18, 2023
Int. Cl. B25D 11/12 (2006.01); B25D 17/06 (2006.01); B25D 17/26 (2006.01)
CPC B25D 11/12 (2013.01) [B25D 17/26 (2013.01); B25D 2217/0065 (2013.01); B25D 2250/121 (2013.01); B25D 2250/345 (2013.01); B25D 2250/365 (2013.01)] 15 Claims
OG exemplary drawing
 
1. An electropneumatic impact mechanism for an electric hand-held power tool, the impact mechanism comprising:
a transmission housing;
a guide tube arranged at least partially in the transmission housing;
an exciter piston movable in the guide tube;
a connecting rod coupled to the exciter piston; and
an eccentric wheel designed as an externally toothed gearwheel and coupled to the connecting rod on one side and being mounted so as to be rotatable with respect to the transmission housing about an axis of rotation on the other side, the axis of rotation defining an axial direction;
an axial gap being provided between an eccentric wheel surface facing the connecting rod and a connecting rod surface facing the eccentric wheel;
a radial spacing being provided between a contact point furthest away from the axis of rotation in a radial direction between the connecting rod and the eccentric wheel and a point in the circumference of a root circle of the eccentric wheel closest to the contact point; and
a lubrication space separating element received in the axial gap and in the radial spacing, the lubrication space separating element having a sleeve-shaped sealing chamber for receiving a pinion of an electric motor.