The invention relates to a die casting ring (1) internally fitted with radial teeth (11) to be engaged into matching seats (22) provided on a piston (2). This piston-ring assembly prevents mutual rotation or axial translation, in addition to ensuring an optimal seal against infiltration of liquid metal during the die casting process. When the ring has a cutout (10), it can be mounted accurately onto the piston because the teeth (11) allow the cutout to be positioned anywhere relative to the piston.

Build cylinder arrangements for machines for the layered production of three-dimensional objects by sintering or melting with a high-energy beam, of powdered material, are disclosed and have a base member and a piston that can be moved on an inner side of the base member along a central axis of the base member. The piston has at its upper side a substrate for building a three-dimensional object, and on the piston is a seal in abutment with the inner side of the base member for sealing the powdered material. The seal is a circumferential fiber metal seal of metal fibers that are pressed together and the pressed metal fibers are arranged with resilient compression stress between the piston and the inner side of the base member.

The present disclosure provides a sealing ring assembly with one or more piston-integrated gap cover features, configured to seal a high-pressure region from a relatively lower pressure region of a piston and cylinder device. The sealing ring assembly may include two rings which each may include one or more ring segments. The one or more gap-cover features, which may be in the form of protrusions in the piston ring groove, may engage with corresponding flat sections of the ring segments. As the sealing ring wears, the gap-cover features may stay engaged with the ring segments, thereby maintaining a seal.

A piston main body in a piston assembly of a fluid pressure cylinder includes a first piston member and a second piston member including a plate-shaped member. The first piston member and the second piston member are joined in a state overlapping in the axial direction of a piston rod. The second piston member is not provided with a hole that passes through in the plate thickness direction.

A novel cleaning container is disclosed for backflushing and hence clean an espresso machine. The container may include a body having a top, an opposing bottom, and an interior cavity for holding water, detergent, and/or other cleaning fluid. A piston is slidably disposed within the interior cavity between up and down positions, wherein the piston and an opening of the body at the top define a variable volume for cleaning the machine. A spring is seated firmly within the body underneath the piston for biasing the piston to the up position. A stopper disposed about the top of the piston limits the motion of the piston at the top of the body. One or more grooves within the body are in fluid communication with one or more outlets to permit fluid to exit the body during cleaning. The body may be transparent or translucent.

An internal combustion may include a cylinder having a first combustion chamber at one end and a second combustion chamber at an opposing end, first and second cylinder heads located at an end of the first and second combustion chambers, respectively, and a double-faced piston slidably mounted within the cylinder. The piston may be configured to move in the cylinder in a work stroke from one end to another. The work stroke may include an expansion stroke portion and a non-expansion stroke portion. The non-expansion stroke portion may include a momentum stroke portion, and a compression stroke portion. The engine may further include first and second piston rod portions extending from opposite faces of the piston. Passageways in the piston rod portions may be configured to communicate gases between a combustion chamber and other locations.

The invention relates to a hydraulic tool mount having a bore into which a sealing piston is inserted, wherein the sealing piston comprises a pin, a seal and a head which are arranged one behind the other in an axial direction (A) and thus form a stack, wherein the seal comprises a circumferential sealing lip for abutment and sealing against an inner wall of the bore in order to achieve a first sealing effect, and the bore comprises a sealing seat which, when the sealing piston is inserted, forms a stop for the head in axial direction (A), so that, in an end position of the sealing piston, the head abuts the sealing seat and thereby closes the bore in order to achieve a second sealing effect. The invention further relates to a corresponding sealing piston.

A valve for an air system in an aircraft engine, comprising: a housing defining a chamber having a valve axis circumscribed by a sealing surface; and a piston assembly within the chamber including: a sealing ring; and a body extending annularly about a piston axis collinear with the valve axis, having a first and a second piston surface axially spaced apart, a radially outer piston surface extending axially and located between the first and second piston surfaces, and an annular groove extending radially inwardly from the radially outer piston surface having first and second groove walls spaced apart and axially facing one another, the sealing ring within the annular groove, the body including: a first member defining the first piston surface and the first groove wall; and a second member defining the second piston surface and the second groove wall, the first member and the second member in mating engagement.

Disclosed are seal arrangements in a hydraulic device. The seal arrangement includes a seal channel defining a loop. A seal is seated within the seal channel. A coolant flow passage has a first part intersecting with the seal channel at a first point and a second part intersecting with the seal channel at a second point. The first part of the coolant flow passage is configured to provide hydraulic fluid to the seal channel such that, at the first point, a first portion of the hydraulic fluid flows in a first direction around the loop and a second portion of the hydraulic fluid flows in a second direction opposite to the first direction around the loop. At the second point, the first portion of hydraulic fluid and the second portion of hydraulic fluid are configured to flow into the second part of the coolant flow passage.

A piston assembly is provided for a human-powered vehicle. The piston assembly includes a main body, a primary seal and a secondary seal. The main body is configured to be movable from a rest position to an actuated position along an actuation direction in a cylinder bore. The primary seal includes a primary seal body arranged on the main body, the primary seal body being made of the first seal material. The secondary seal includes a secondary seal body arranged on the main body at upstream of the primary seal with respect to the actuation direction. The secondary seal body is made of a second seal material that is more elastic than the first seal material.