Rotary piston pump

1. Rotary piston pump for semi-solid products, in particular for minced meat, comprising:

a stator ( 4 ) defining a cylindrical cavity,

a rotor or barrel ( 5 ) housed in said cylindrical cavity, able to be driven in rotation by a motor ( 10 ), said rotor comprising an array of bores ( 51 ) spaced circumferentially, wherein pistons ( 9 ) are mounted,

a mechanical cam cooperating with the pistons in order to provoke during the rotation of the barrel an alternating back and forth movement of said pistons between a low position and a high position,

a lid ( 6 ) closing the cylindrical cavity,

a feeding orifice ( 63 ) coming into communication with at least one cylindrical chamber formed by the barrel cylindrical bore and a piston associated therewith, and intended to be in communication with a hopper ( 3 ),

a discharging orifice ( 64 ) able to come simultaneously in communication with at least two consecutive cylindrical chambers,

and vacuuming means for vacuuming cylindrical chambers ( 8 ) for filling thereof,

characterised in that said vacuuming means include at least one vacuuming channel ( 52 ) connecting to the lower part of each cylindrical chamber, said vacuuming means being able to vacuum by the bottom each cylindrical chamber by the vacuuming channel therewith when the piston associated therewith is in lower position.

2. Pump according to claim 1 , characterised in that said vacuuming means are able to stop the vacuuming of each cylindrical chamber ( 8 ) by the vacuuming channel therewith ( 52 ) prior to the moving of said cylindrical chamber opposite the discharging orifice ( 64 ).

3. Pump according to claim 1 , characterised in that each cylindrical chamber ( 8 ) includes at least one vacuuming channel ( 52 ) formed on the cylindrical wall of the bore ( 51 ).

4. Pump according to claim 3 , characterised in that each vacuuming channel is formed by a vertical groove ( 52 ) placed on the cylindrical wall of the bore ( 51 ), said groove extending from lower side ( 5 b ) of the barrel over a height that is sufficient to connect to the cylindrical chamber ( 8 ) when piston ( 9 ) is in low position, said vacuuming means being able to vacuum the lower chamber of stator ( 4 ) on which said vertical grooves connect.

5. Pump according to claim 4 , characterised in that each piston ( 9 ) is able to be moved by the mechanical cam from its low position towards an intermediary low position wherein the piston blocks off said vacuuming channel(s) ( 52 ), with the movement being carried out upstream from the discharging orifice ( 64 ), when said piston is located at least partially opposite feeding orifice ( 63 ).

6. Pump according to claim 1 , characterised in that each cylindrical chamber ( 8 ) includes at least two vacuuming channels ( 52 ) distributed at a regular angular interval.

7. Pump according to claim 1 , characterised in that each piston ( 9 ) includes a piston head ( 900 ) connected to a piston rod ( 902 ), said head comprising a body ( 903 ) covered with a packing ( 904 ) made from a material having sliding properties, by inserting between the body and said packing an intermediary layer ( 905 ) having elastic properties, said packing forming a sealing surface through which piston ( 9 ) comes into sliding contact, in a substantially sealed manner, against the cylindrical wall of the bore ( 51 ).

8. Pump according to claim 1 , characterised in that vacuuming means further comprises a vacuuming orifice ( 65 ) for vacuuming the chambers from the top, said pump comprising a vacuum pump system ( 13 ) to which are connected vacuuming channels ( 52 ) of the cylindrical chambers, as well as said vacuuming orifice ( 65 ).

9. Pump according to claim 1 , characterised in that the cylindrical chambers ( 8 ) are positioned axially, pistons ( 9 ) able to be moved in parallel to the axis of rotation of the barrel, said lid ( 6 ) being equipped with the feeding orifice ( 63 ) and the discharging orifice ( 64 ).

10. Pump according to claim 1 , characterised in that it further comprises cutting means, comprising a blade ( 70 ) positioned along the downstream edge of the feeding orifice ( 63 ), in order to cut the pieces of products protruding from the cylindrical chambers during their passage beyond the feeding orifice.

11. Rotary piston pump for semi-solid products, in particular for minced meat, comprising:

a stator ( 4 ) defining a cylindrical cavity,

a rotor or barrel ( 5 ) housed in said cylindrical cavity, able to be driven in rotation by a motor ( 10 ), said rotor comprising an array of bores ( 51 ) spaced circumferentially, wherein pistons ( 9 ) are mounted,

a mechanical cam cooperating with the pistons in order to provoke during the rotation of the barrel an alternating back and forth movement of said pistons between a low position and a high position,

a lid ( 6 ) closing the cylindrical cavity,

a feeding orifice ( 63 ) coming into communication with at least one cylindrical chamber formed by the barrel cylindrical bore and a piston associated therewith, and intended to be in communication with a hopper ( 3 ),

a discharging orifice ( 64 ) able to come simultaneously in communication with at least two consecutive cylindrical chambers, and vacuuming means for vacuuming cylindrical chambers ( 8 ) for filling thereof,

characterised in that it further comprises cutting means, comprising a blade ( 70 ) positioned along the downstream edge of the feeding orifice ( 63 ), in order to cut the pieces of products protruding from the cylindrical chambers during their passage beyond the feeding orifice.