US 9,810,322 B2
Piston unit of a working cylinder
Josef Bueter, Haren/Altenberge (DE)
Assigned to Buemach Engineering International B.V., Ta Emmen (NL)
Appl. No. 14/429,457
Filed by BÜMACH ENGINEERING INTERNATIONAL B.V., TA Emmen (NL); and Josef Bueter, Haren/Altenberge (DE)
PCT Filed Sep. 19, 2013, PCT No. PCT/DE2013/000532
§ 371(c)(1), (2) Date Mar. 19, 2015,
PCT Pub. No. WO2014/044244, PCT Pub. Date Mar. 27, 2014.
Claims priority of application No. 20 2012 008 997 U (DE), filed on Sep. 19, 2012.
Prior Publication US 2015/0226326 A1, Aug. 13, 2015
Int. Cl. F16J 1/12 (2006.01); F16B 3/04 (2006.01); F15B 15/14 (2006.01)
CPC F16J 1/12 (2013.01) [F15B 15/1447 (2013.01); F16B 3/04 (2013.01); Y10T 403/7075 (2015.01)] 8 Claims
OG exemplary drawing
 
1. A piston unit of a working cylinder, comprising:
a first coupling partner being a piston and a second coupling partner being a piston rod, said second coupling partner being coaxially inserted into a bore within said first coupling partner along a longitudinal axis;
said first and second coupling partners each having a respective annular groove formed therein, said annular groove of said second coupling partner being an external groove on an outer surface of said piston rod and said annular groove of said first coupling partner being an internal groove on an internal surface of said bore in said piston, said annular grooves of said first and second coupling partners being disposed opposite one another and defining an annular-groove chamber, said first coupling partner having an access opening extending from an outer surface of the piston to said annular-groove chamber;
a coupling strand for engaging into said annular grooves of said first and second coupling partners, said coupling strand being insertable into said annular-groove chamber through said access opening, an engagement of said coupling strand into said annular grooves of said first and second coupling partners effecting a positive locking connection between said first and second coupling partners;
said second coupling partner having an oversize in relation to an internal diameter of said bore of said first coupling partner, for providing an interference fit effecting a non-positive locking connection between said first and second coupling partner, said interference fit preventing relative movement between said first and second coupling partners for preventing damage to seal elements of the piston unit;
a hybrid coupling action produced by said interference fit and said coupling strand, said hybrid coupling action including a frictional locking between said first and second coupling partners resulting from said interference fit for axially and rotational locking said first and second coupling partners to one another, said coupling strand for accommodating axial forces acting on said first and second coupling partners.