Spin-blast apparatus

Claim 2

In an apparatus for abrading the interior surface of a pipe by blasting abrasive from a rotating nozzle which is caused to travel interiorly along the pipe, a swivel assembly for coupling the rotating nozzle to a blast supply conduit, comprising: a cylindrical housing, a tubular nozzle support conduit journalled for rotation within the housing, the support conduit having a discharge end projecting from one end of the housing for connection to the nozzle and an intake end projecting from the other end of the housing, a flanged adaptor having a tubular portion for connection to the supply conduit, an annular clamping plate, means clamping the adaptor and the clamping plate to said other end of the housing coaxially therewith, an annular sealing gasket clamped between the flanged adaptor and the clamping plate, the gasket having a peripheral portion extending radially inwards beyond the inner periphery of the clamping plate, the intake end of the support conduit bearing against said peripheral portion of the gasket, the clamping plate being spaced from said other end of the cylindrical housing by spacers to define therewith a space which is open to atmosphere.

Claim 3

A swivel assembly according to claim 1, wherein the inner peripheral edge of the gasket is substantially aligned with the interior surface of the support conduit.

Claim 4

A swivel assembly according to claim 1, wherein the support conduit is journalled within the cylindrical housing by ball bearing assemblies, the ball bearing assemblies being isolated from said space by annular partitions located between the housing and the support conduit adjacent to the ends of the housing.

Claim 5

Apparatus for abrading the interior surface of a pipe, comprising: a carriage adapted to travel interiorly along the pipe, a cylindrical housing mounted on the carriage, the cylindrical housing having an axis aligned with the axis of the pipe along which the carriage is adapted to travel, a tubular nozzle support conduit journalled for rotation within the housing by bearing means, said bearing means locating the support conduit coaxially with the housing, the support conduit having a discharge end projecting from one end of the housing and an intake end projecting from the other end of the housing, a rotary nozzle assembly coupled to said discharge end, a blast supply conduit for supplying an air/abrasive mixture under pressure to the intake of the support conduit, a flanged adaptor having a tubular portion to which the supply conduit is connected, an annular clamping plate, means clamping the adaptor and the clamping plate to said other end of the housing coaxially therewith, an annular sealing gasket clamped between the flanged adaptor and the clamping plate, the gasket having a peripheral portion extending radially inwards beyond the inner periphery of the clamping plate, the intake end of the support conduit and the discharge end of the supply conduit bearing against opposite sides of said peripheral portion, and spacers interposed between the clamping plate and said other end of the cylindrical housing whereby to define therebetween a space which is open to atmosphere.

Claim 6

Apparatus for abrading the interior surface of a pipe, comprising: a carriage adapted to travel interiorly along the pipe, a cylindrical housing mounted on the carriage, the cylindrical housing having an axis aligned with the axis of the pipe along which the carriage is adapted to travel, a tubular nozzle support conduit journalled for rotation within the housing by bearing means, said bearing means locating the support conduit coaxially with the housing, the support conduit having a discharge end projecting from one end of the housing and an intake end projecting from the other end of the housing, a rotary nozzle assembly coupled to said discharge end, a blast supply conduit for supplying an air/abrasive mixture under pressure to the intake of the support conduit, a flanged adaptor having a tubular portion to which the supply conduit is connected, an annular clamping plate, means clamping the adaptor and the clamping plate to said other end of the housing coaxially therewith, an annular sealing gasket clamped between the flanged adaptor and the clamping plate, the gasket having a peripheral portion extending radially inwards beyond the inner periphery of the clamping plate, the intake end of the support conduit and the discharge end of the supply conduit bearing against opposite sides of said peripheral portion, and spacers interposed between the clamping plate and said other end of the cylindrical housing whereby to define therebetween a space which is open to atmosphere.

Claim 7

Apparatus according to claim 4, wherein the discharge end of the supply conduit is constituted by an annular hard washer.

Claim 8

Apparatus according to claim 5, wherein the supply conduit and the support conduit are of the same internal diameter, said gasket and said hard washer each providing a circular opening of the same diameter as said internal diameter.

Claim 9

Apparatus according to claim 4, said bearing means being enclosed between annular partitions located between the housing and the support conduit adjacent to the ends of the housing.

Claim 10

Apparatus according to claim 7, said bearing means being constituted by a pair of axially spaced ball bearing assemblies.

Claim 11

Apparatus according to claim 4, wherein the nozzle assembly is driven by an electric motor mounted on the carriage.