Piston pump stroke adjustment mechanism

A pump for dispensing fluids from a reservoir comprising:

• a piston-chamber forming member having a cylindrical chamber about a central axis, said chamber having a chamber wall, an inner end in fluid communication with the reservoir and an outer open end,
• a piston forming element having a piston portion coaxially slidably received in the chamber with an outer portion of the piston forming element extending outwardly from the open end of the chamber,
• the outer portion including a hollow discharge tube extending generally radially outwardly from the central axis from an inlet end to a discharge outlet,
• the piston portion being generally cylindrical in cross-section with a central axially extending hollow stem having a central passageway with an inner end opening into the chamber and an outer end communicating with the inlet end of the hollow discharge tube,
• an axially outwardly directed stroke stop surface fixedly relative to the piston-chamber forming member,
• a stroke stop member carried on the discharge tube for engagement with the stroke stop surface to limit inward coaxial sliding of the piston forming element relative the piston-chamber forming member,
• the stroke stop member journalled on the discharge tube for pivoting about a radial axis extending radially from the central axis between a first rotational position and a second rotational position,
• in the first rotational position the stroke stop member engaging the stroke stop surface to limit inward coaxial sliding of the piston forming element relative the piston-chamber forming member at a first axial location,
• in the second rotational position the stroke stop member engaging the stroke stop surface to limit inward coaxial sliding of the piston forming element relative the piston-chamber forming member at a second axial location which is different than the first axial location,
• wherein reciprocal sliding of the piston forming element relative the piston-chamber forming member dispensing fluid from the reservoir out the discharge outlet, and
• including a generally cylindrical metal tube forming the discharge tube and providing the passageway therein, the metal tube bent so as to form an extension of the discharge tube extending continuously inwardly from the outer portion along the central axis centrally through the piston portion.

A pump for dispensing fluids from a reservoir comprising:

• a piston-chamber forming member having a cylindrical chamber about a central axis, said chamber having a chamber wall, an inner end in fluid communication with the reservoir and an outer open end,
• a piston forming element having a piston portion coaxially slidably received in the chamber with an outer portion of the piston forming element extending outwardly from the open end of the chamber,
• the outer portion including a hollow discharge tube extending generally radially outwardly from the central axis from an inlet end to a discharge outlet,
• the piston portion being generally cylindrical in cross-section with a central axially extending hollow stem having a central passageway with an inner end opening into the chamber and an outer end communicating with the inlet end of the hollow discharge tube,
• an axially outwardly directed stroke stop surface fixedly relative to the piston-chamber forming member,
• a stroke stop member carried on the discharge tube for engagement with the stroke stop surface to limit inward coaxial sliding of the piston forming element relative the piston-chamber forming member,
• the stroke stop member journalled on the discharge tube for pivoting about a radial axis extending radially from the central axis between a first rotational osition and a second rotational position,
• in the first rotational position the stroke stop member engaging the stroke stop surface to limit inward coaxial sliding of the piston forming element relative the piston-chamber forming member at a first axial location,
• in the second rotational position the stroke stop member engaging the stroke stop surface to limit inward coaxial sliding of the piston forming element relative the piston-chamber forming member at a second axial location which is different than the first axial location,
• wherein reciprocal sliding of the piston forming element relative the piston-chamber forming member dispensing fluid from the reservoir out the discharge outlet, and
• wherein the stroke stop member is formed separately from the a piston forming element and is removable and separable therefrom,
• the stroke stop member having a slotway extending radially of the radial axis from the bore to an entry opening in a side of the stroke stop member,
• the slotway permitting entry of the discharge tube through the entry opening via the slotway into the bore.

A pump for dispensing fluids from a reservoir comprising:

• a piston-chamber forming member having a cylindrical chamber about a central axis, said chamber having a chamber wall, an inner end in fluid communication with the reservoir and an outer open end,
• a piston forming element having a pistonportion coaxially slidably received in the chamber with an outer portion of the piston forming element extending outwardly from the open end of the chamber,
• the outer portion including a hollow discharge tube extending generally radially outwardly from the central axis from an inlet end to a discharge outlet,
• the piston portion being generally cylindrical in cross-section with a central axially extending hollow stem having a central passageway with an inner end opening into the chamber and an outer end communicating with the inlet end of the hollow discharge tube,
• an axially outwardly directed stroke stop surface fixedly relative to the piston-chamber forming member,
• a stroke stop member carried on the discharge tube for engagement with the stroke stop surface to limit inward coaxial sliding of the piston forming element relative the piston-chamber forming member,
• the stroke stop member journalled on the discharge tube for pivoting about a radial axis extending radially from the central axis between a first rotational position and a second rotational position,
• in the first rotational position the stroke stop member engaging the stroke stop surface to limit inward coaxial sliding of the piston forming element relative the piston-chamber forming member at a first axial location,
• in the second rotational position the stroke stop member engaging the stroke stop surface to limit inward coaxial sliding of the piston forming element relative the piston-chamber forming member at a second axial location which is different than the first axial location,
• wherein reciprocal sliding of the piston forming element relative the piston-chamber forming member dispensing fluid from the reservoir out the discharge outlet, and
• wherein the stroke stop member is rectangular in cross-section normal to the radial axis, the two surfaces along the short sides of the rectangle forming first engagement surfaces equidistant from the radial axis and one of which engages in the first rotational position with stroke stop surface to limit inward coaxial sliding of the piston forming element and, the two surfaces along the long sides of the rectangle forming second engagement surfaces equidistant from the radial axis and one of which engages in the second rotational position with stroke stop surface to limit inward coaxial sliding of the piston forming element.

A pump for dispensing fluids from a reservoir comprising:

• a piston-chamber forming member having a cylindrical chamber about a central axis, said chamber having a chamber wall, an inner end in fluid communication with the reservoir and an outer open end,
• a piston forming element having a piston portion coaxially slidably received in the chamber with an outer portion of the piston forming element extending outwardly from the open end of the chamber,
• the outer portion including a hollow discharge tube extending generally radially outwardly from the central axis from an inlet end to a discharge outlet,
• the piston portion being generally cylindrical in cross-section with a central axially extending hollow stem having a central passageway with an inner end opening into the chamber and an outer end communicating with the inlet end of the hollow discharge tube,
• an axially outwardly directed stroke stop surface fixedly relative to the piston-chamber forming member,
• a stroke stop member carried on the discharge tube for engagement with the stroke stop surface to limit inward coaxial sliding of the piston forming element relative the piston-chamber forming member,
• the stroke stop member joumalled on the discharge tube forpivoting about a radial axis extending radially from the central axis between a first rotational position and a second rotational position,
• in the first rotational position the stroke stop member engaging the stroke stop surface to limit inward coaxial sliding of the piston forming element relative the piston-chamber forming member at a first axial location,
• in the second rotational position the stroke stop member engagingthe stroke stop surface to limit inward coaxial sliding of the piston forming element relative the piston-chamber forming member at a second axial location which is different than the first axial location,
• wherein reciprocal sliding of the piston forming element relative the piston-chamber forming member dispensing fluid from the reservoir out the discharge outlet, and
• wherein the stroke stop member is rectangular in cross-section normal to the radial axis, the two surfaces along the short sides of the rectangle forming first and second engagement surfaces respectively at different distances from the radial axis,
• the two surfaces along the long sides of the rectangle forming third and fourth engagement surfaces respectively at different distances from the radial axis than each other and than the first and second engagement surfaces,
• the first engagement surface engages in the first rotational position with stroke stop surface to limit inward coaxial sliding of the piston forming element,
• the second engagement surface engages in the second rotational position with stroke stop surface to limit inward coaxial sliding of the piston forming element,
• the third engagement surface engages in a third rotational position with stroke stop surface to limit inward coaxial sliding of the piston forming element,
• the fourth engagement surfaces engages in a fourth rotational position with stroke stop surface to limit inward coaxial sliding of the piston forming element.