Liquid spray jet assembly and a mineral mining machine cutting head incorporating such assembly

Abstract

A liquid spray jet assembly is disclosed destined particularly for use in dust and debris laden conditions such as on the cutting heads of mineral mining machines. The assembly comprises a housing for securing to a piece of apparatus, a jet which is a push fit into the interior of the housing and a resilient seating between the jet and a part of the housing. The seating is made from a compressible material and is so compressed by the jet when positioned in the housing that the restoring force causes part of the jet to bear against a surface of the housing facing towards the seating so holding the jet within the housing. The housing and the jet have communicating passages for the passage of liquid therethrough. Use of a push fit avoids the previously used screw threaded communications and makes jet replacement an extremely simple operation.

I claim: .[.1. A liquid spray jet assembly comprising a rigid housing designed to be secured to a piece of apparatus, a jet fitted within the housing, retaining means for releasably retaining the jet within the housing, and communicating passages through the housing and the jet for the passage of liquid therethrough, in which the housing and jet are so shaped that the jet is a push fit into the housing through an opening therein and is removable from the housing through said opening, and a resilient seating is provided between the jet and a part of the housing, the seating being made from a compressible material that deforms to allow fitting and removal of the jet and that is so compressed by the jet when positioned in the housing that the restoring force due to such compression causes part of the jet to be forced towards a surface of the housing facing towards the seating, said surface at least partially constituting the retaining means, and to be held thereby in position within the housing..]. .[.2. A liquid spray jet assembly according to claim 1 in which stop means are provided for limiting movement of the jet away from the surface of the housing that forms the retaining means to a distance such that the resilient seating is not fully compressed..]. .[.3. A liquid spray jet assembly according to claim 1 in which a chamber is formed within the housing for receiving the jet and the seating, and the seating is in the form of an annular member surrounding the region of communication of the passages through the housing and the jet and shaped so that when liquid under pressure is supplied through the passage in the housing the annular member seals against the jet and against the wall of 
     
        the chamber..]. .[.4.  A liquid spray jet assembly according to claim 3 in which the jet is a push fit into the chamber through a passageway co-axial with and smaller than the chamber, and the surface of the housing that forms the retaining means is part of that face of the chamber where the passageway opens into the chamber and transverse to the axis of the chamber..]. .[.5. A liquid spray jet assembly according to claim 4 in which the walls of the passageway taper inwardly towards the chamber, and part of the jet has an axially outer face, an axially inner face and a circumferential face joining the axially outer and inner faces and tapering inwardly towards the axially inner face..]. .[.6. A cutting head for a mineral mining machine having a plurality of pick boxes, and having secured to the head, at least one liquid spray jet assembly comprising a rigid housing secured to the head, a jet fitted within the housing, retaining means for retaining the jet within the housing, and communicating passages through the housing and the jet for the passage of liquid therethrough, in which the housing and jet are so shaped that the jet is a push fit into the housing through an opening therein and is removable from the housing through the opening, and a resilient seating is provided between the jet and a part of the housing, the seating being made from a compressible material that deforms to allow fitting and removal of the jet and that is so compressed by the jet when positioned in the housing that the restoring force due to such compression causes part of the jet to be forced towards a surface of the housing facing towards the seating, said surface at least partially constituting the retaining means, and to be held thereby in position within the housing..]. .[.7. A cutting head according to claim 6 in which stop means are provided for limiting movement of the jet away from the surface of the housing that forms the retaining means to a distance such that the resilient seating is not fully compressed..]. .[.8. A cutting head according to claim 6 in which a chamber is formed within the housing for receiving the jet and the seating, and the seating is in the form of an annular member surrounding the region of communication of the passages through the housing and the jet and shaped so that when liquid under pressure is supplied through the passage in the housing the annular member seals against the jet and against the wall of the chamber..]. .[.9. A cutting head according to claim 8 in which the jet is a push fit into the chamber through a passageway co-axial with and smaller than the chamber, and the surface of the housing that forms the retaining means is part of that face of the chamber where the passageway opens into the chamber and transverse to the axis of the chamber..]. .[.10. A cutting head according to claim 9 in which the walls of the passageway taper inwardly towards the chamber, and part of the jet has an axially outer face, an axially inner face and a circumferential face joining the axially outer and inner faces and 
     
     
        tapering inwardly towards the axially inner face..]. .Iadd.11.  A liquid spray jet assembly comprising a rigid housing designed to be secured to a piece of apparatus, the housing have a passage opening into a chamber therein, a resilient seating within the chamber, a jet releasably fitted within the housing, the jet having an imaginary centerline and having a retaining part having opposed retaining portions and having a passage therethrough communicating with the passage into the housing for the passage of liquid therethrough, in which the housing and the jet are so shaped that the jet is a push fit into the housing through an opening therein and is removable from the chamber through said opening in the housing, the opening having a centerline and having opposed retaining sections the distance between which is less than a corresponding dimension of said opposed retaining portions of said retaining part of the jet, the resilient seating being made from a compressible material that is deformable to such extent during insertion of the jet to allow the jet to be angularly tilted with respect to said center line of said opening to allow one of said retaining portions to be moved under the corresponding one of said retaining sections and then allow the other of said retaining portions to be moved past said other of said retaining sections so that said retaining part is located partially beneath the opposed retaining sections, in which position the seating is compressed by the jet and the restoring force due to such compression biases the jet to engage the retaining part beneath the opposed retaining sections, such engagement being the sole region of engagement between the jet and the housing, thereby to hold the jet in position within the housing and effect a seal that directs liquid from the housing passage into the jet passage, and the seating further being deformable to allow tilting movement of the jet for disengagement within said region and removal of the jet from the housing through the opening therein, said tilting movements for engagement and disengagement being such as to cause the centerline of the jet to be angularly displaced with respect to the centerline of said opening within 
     
     
        a plane containing both said centerlines. .Iaddend. .Iadd.12.  A liquid spray jet assembly according to claim 11 in which stop means are provided for limiting movement of the retaining part of the jet away from the opposed retaining sections to a distance such that the resilient seating is not fully compressed. .Iaddend. .Iadd.13. A liquid spray jet assembly according to claim 11 in which the resilient seating is so shaped that when liquid under pressure is supplied through the housing, part of the seating effects a seal communicating the two passages and part effects a seal against the wall of the chamber. .Iaddend. .Iadd.14. A liquid spray jet assembly according to claim 11 in which the chamber and the retaining part of the jet are substantially circular in cross-section, the seating member is annular, and the opposed sections of the opening are diametrically opposed arcuate sections co-axial with the chamber and with a diameter less than the maximum diameter of the retaining part of the jet. .Iaddend. .Iadd.15. A liquid spray jet assembly according to claim 11 in which the opening has walls which taper inwardly towards the chamber, and the retaining part of the jet has an axially outer face, an axially inner face and a circumferential face joining the axially outer and inner faces and tapering inwardly towards the axially inner face. .Iaddend. 
     
     
        .Iadd.16.  A cutting head for a mineral mining machine having a plurality of pick boxes and having secured to the head at least one liquid spray jet assembly, comprising a rigid housing secured to the head, the housing having a passage opening into a chamber therein, a resilient seating within the chamber, a jet releasably fitted within the housing, the jet having an imaginary centerline and having a retaining part having opposed retaining portions and having a passage therethrough communicating with the passage into the housing for the passage of liquid therethrough, in which the housing and the jet are so shaped that the jet is a push fit into the housing through an opening therein and is removable from the chamber through said opening in the housing, the opening having a centerline and having opposed retaining sections the distance between which is less than a corresponding dimension of said opposed retaining portions of said retaining part of the jet, the resilient seating being made from a compressible material that is deformable to such extent during insertion of the jet to allow the jet to be angularly tilted with respect to said center line of said opening to allow one of the retaining portions to be moved under the corresponding one of said retaining sections and then allow the other of said retaining portions to be moved past said other of said retaining sections so that said retaining part is located partially beneath the opposed retaining sections, in which position the seating is compressed by the jet and the restoring force due to such compression biases the jet to engage the retaining part beneath the opposed retaining sections, such engagement being the sole region of engagement between the jet and the housing, thereby to hold the jet in position within the housing and effect a seal that directs liquid from the housing passage into the jet passage, and the seating further being deformable to allow tilting movement of the jet for disengagement within said region and removal of the jet from the housing through the opening therein, said tilting movement for engagement and disengagement being such as to cause the centerline of the jet to be angularly displaced with respect to the centerline of said opening within a plane containing both 
     
     
        said centerlines. .Iaddend. .Iadd.17.  A cutting head according to claim 16 in which stop means are provided for limiting movement of the retaining part of the jet away from the opposed retaining sections to a distance such that the resilient seating is not fully compressed. .Iaddend. .Iadd.18. A cutting head according to claim 16 in which the resilient seating is so shaped that when liquid under pressure is supplied through the housing, part of the seating effects a seal communicating the two passages and part effects a seal against the wall of the chamber. .Iaddend. .Iadd.19. A cutting head according to claim 16 in which the chamber and the retaining part of the jet are substantially circular in cross-section, the seating member is annular, and the opposed sections of the opening are diametrically opposed arcuate sections co-axial with the chamber and with a diameter less than the maximum diameter of the retaining part of the jet. .Iaddend. .Iadd.20. A cutting head according to claim 16 in which the opening has walls which taper inwardly towards the chamber, and the retaining part of the jet has an axially outer face, an axially inner face and a circumferential face joining the axially outer and inner faces and tapering inwardly towards the axially inner face. .Iaddend.