Patent Description:
Inversion units are used to refurbish piping and plumbing systems in buildings and structures. The inversion units allow to reline pipes instead of removing old pipes and installing new pipes and therewith allow to provide for a smoother and quicker process of refurbishing piping and plumbing system. For relining, a sleeve made of fabric that is impregnated with a resin prior to rolling the sleeve up on a reel of an inversion unit. The reel is typically enclosed by a drum that is designed to be airtight when the sleeve is connected to an adapter for entering the piping system. Once the impregnated fabric is connected to the adapter and therewith ready to enter a pipe, the drum is pressurized with a gas, typically air, via a gas inlet. Due to the pressure in the drum and the connection to the adapter, the impregnated fabric is entering the pipe in an inverted manner. The inverted and impregnated fabric will therewith seal the piping once it is installed and cured.

In order to observe that everything is running smooth and that no problems occur a window is typically provided on the drum as shown for instance in the <CIT>. An opening formed in the drum, which opening is covered by the window is used so that the workers can reach into the drum to perform manual work in case of issues in the drum during operation or during reeling up of the impregnated fabric. The window in the <CIT> is a lock that is screwed onto a thread of the opening of the drum. The size of the window in the <CIT> is limited and the opening and the closing of the window takes time due to the screwing movement that is required.

The present invention seeks to provide a larger window having a smooth and reliable locking mechanism.

An object of the present invention is to provide an inversion unit that is easy to handle and provides for an efficient work process.

In view of the above-mentioned problems the inventor of the present invention has discovered that it is possible to change the design of the window on the housing or drum of the inversion unit for better and smoother access to the window by using a bayonet mechanism in combination with a handle.

Disclosed herein is a inversion unit comprising a housing, a reel for a liner partially arranged in the housing, and a base assembly. The housing is arranged on the base assembly, said housing comprising a gas inlet, an outlet for the liner, an opening comprising a window and a window locking mechanism being designed to be manoeuvred into an open position in which the window is open and/or unlocked and a closed position in which the window is closed and/or locked, The window locking mechanism is designed as a bayonet catch and comprises a motion link assembly and a matching projection assembly. The window locking mechanism further comprises a handle and a hinge, the handle being pivotably connected to the hinge wherein one of the motion link assembly or the matching projection assembly is arranged on the window and the other of the matching projection assembly or the motion link assembly is arranged on an edge of the opening. The hinge is arranged on the housing and the handle is pivotably connected to the window so that the window can be easily opened and closed in a bayonet catch manner using the handle.

The above-described inversion unit improves the handling of the window using an efficient opening and closing mechanism embodied as the window locking mechanism.

The above-described embodiment of the inversion unit further also covers the kinematic reversed arrangement of the motion link assembly and the matching projection assembly. This means that the motion link assembly may either be arranged on an edge of the opening and the matching projection assembly on the window or the other way around. Both variants work and are herewith covered with the claims presented herein.

In an embodiment the window comprises a seal that is designed to seal the opening when the window locking mechanism is in the closed position.

The seal allows to build up the gas pressure in the housing via the gas inlet in a controlled manner by sealing the inside of the housing.

The opening may be larger than the outlet for the liner.

This improves access to the inside of the housing and therewith the access to the part of the reel that is arranged in the housing.

In an embodiment the handle is designed as a lever that can be moved towards the housing for manoeuvring the window locking mechanism into the closed position and that can be moved away from the housing for manoeuvring the window locking mechanism into the open position.

The handle in the form of a lever makes it very easy for an operator or worker to open and close the window using the window locking mechanism.

In another embodiment the window can be rotated or pivotated away from the opening when the window locking mechanism is in its open position.

The above means that the window can be moved out of the way when the window locking mechanism is in its open position.

In another embodiment the opening may be substantially rectangular. This may allow to use standard components for the window and frame.

In still a further embodiment the housing may comprise a gas outlet for better controlling the gas pressure in the housing.

In an embodiment the base assembly can be disconnected from the housing and wherein the base assembly comprises a base and wheels.

The disconnection of the inversion unit from the base assembly may improve the handling of the inversion unit in tight space(s).

Using wheels connected to the base may improve mobility of the inversion unit and base assembly, respectively.

The base assembly may further be provided with at least one swivelling wheel, which further improves the handling of the inversion unit and base assembly, respectively.

In an embodiment the window further comprises a glass and a frame embedding the glass of the window, said frame being pivotably connected to the handle and said frame comprising the motion link assembly or matching projection assembly.

The above may further improve the robustness of the window and the window locking mechanism. The frame may for example be clamped to the glass and the frame may be made of metal or the like whereby the motion link assembly and the matching projection assembly, respectively, may be integrally formed with the frame.

In still another embodiment the motion link assembly may be arranged in a first plane that is oriented perpendicular to a second plane defined by the window and wherein the matching projection assembly is projecting in a direction perpendicular to the first plane.

The direction of the motion link of the motion link assembly is further oriented so that the window can slide in a linear motion once the handle is operated.

The motion link assembly may comprise two to eight motion link elements, preferably four motion link elements. The motion link elements may be distributed equally on either side of the opening or window while the matching projecting assembly may comprise an equal amount of projections, which are equally distributed so that they match the motion link elements when the window is connected to the opening and when the window locking mechanism is moved into the closed position.

Further aspects and example embodiments are illustrated in the accompanying drawings and/or described in the following description.

The present invention will now be described, for exemplary purposes, in more detail by way of an embodiment(s) and with reference to the enclosed drawings, in which:.

<FIG> illustrates an inversion unit <NUM> comprising a housing <NUM>, a reel <NUM> for a liner arranged partially within the housing <NUM> and a base assembly <NUM>. The housing <NUM> is formed as a drum but it may be formed as a hexagon, octagon, or any other suitable shape. The reel <NUM> comprises a manual wheel <NUM> that can be operated manually by a worker, for example during initial set up of the relining using the inversion unit <NUM>, and an inner reel <NUM>, which is illustrated later on referring to <FIG>. The base assembly <NUM> comprises a base <NUM> and wheels <NUM>, <NUM> whereby at least some of the wheels <NUM>, <NUM> are swivelling wheels <NUM> (c. The housing <NUM> comprises an opening <NUM> coverable by a window <NUM>. The window <NUM> comprises a frame <NUM>, glass <NUM> and a seal (not visible). The window <NUM> is kept in place by a window locking mechanism <NUM>. The window locking mechanism <NUM> is used to open and close the window <NUM> in a safe and secure manner. The window locking mechanism <NUM> can be moved from an open position to a closed position and back.

Turning now to <FIG> another view of the inversion unit <NUM> is shown where the housing <NUM> and an outlet <NUM> of the housing <NUM> is well visible. The outlet <NUM> is used to dispense an impregnated liner (not shown) in an inverted manner into a pipe in order to reline the pipe. The impregnated liner is thereby rolled up onto the reel <NUM> prior to installation and then dispensed via the outlet <NUM> using air pressure that is provided inside the housing <NUM> via a gas inlet <NUM>. The housing <NUM> further comprises a pressure sensor <NUM> and a gas outlet <NUM>. Referring to <FIG> the window locking mechanism <NUM> is herewith further explained in more detail.

The window locking mechanism <NUM> is designed as a bayonet catch and is shown in its closed position in <FIG> illustrates the inversion unit <NUM> shown in a side view with the outlet <NUM> and the manual wheel <NUM> well visible. The pressure sensor <NUM> and the window locking mechanism <NUM> are also well illustrated and in the closed position. The closed position of the window locking mechanism <NUM> is the typical situation during dispensing of the impregnated liner (not shown). In case there is an issue the window <NUM> can be opened via the window locking mechanism <NUM> and the inside of the housing <NUM> can be accessed. The wheels <NUM> and the swivelling wheels <NUM> of the base assembly <NUM> are also well visible. <FIG> illustrates an enlargement of <FIG> and the window locking mechanism <NUM> is herewith explained in more detail referring to <FIG>.

The window locking mechanism <NUM> comprises a motion link assembly <NUM> arranged at an opening <NUM> of the housing <NUM>, a matching projection assembly <NUM> arranged on the frame <NUM> of the window <NUM> and a handle <NUM>. The motion link assembly <NUM> comprises guides and a matching projection assembly <NUM>, which comprises projections that are designed to be embedded slideably in the guides of the motion link assembly <NUM>. The motion link assembly <NUM> and the matching projection assembly <NUM> are working as a bayonet catch. The handle <NUM> in the form of a lever is connected to a hinge <NUM>, which hinge <NUM> is connected to the housing <NUM> or an edge of the opening <NUM>. The hinge <NUM> is further pivotably connected to the frame <NUM> of the window <NUM>. In the closed position of the viewing locking mechanism <NUM> the lever <NUM> is arranged close to the housing <NUM>.

Turning now to <FIG> an unlocked position of the window locking mechanism <NUM> is herewith explained and illustrated. In the unlocked position the lever <NUM> or handle <NUM> is moved upwards and away from the housing <NUM> via the hinge <NUM>. This frees the window <NUM> and the matching projection assembly <NUM> with projections <NUM>, respectively, from the motion link assembly <NUM> with its motion link elements <NUM> arranged on the opening <NUM> and therewith unlocking the window <NUM>.

An unlocked window <NUM> allows a worker to pivot the window <NUM> out of the way so that the inner room or inside of the housing <NUM> can be easily accessed. This is shown in <FIG>.

<FIG> illustrate the window <NUM> pivoted or swivelled away from the opening <NUM>. This leaves the four motion link elements <NUM> well visible. It can be seen that these motion link elements <NUM> comprise an entry gap where the projections <NUM> of the matching projection assembly <NUM> can enter a motion link or guide rail of the motion link elements <NUM> for a form-fit locking when the window <NUM> is manoeuvred into the corresponding position and when the lever <NUM> is moved towards the housing <NUM>. A seal <NUM> may be arranged on the window <NUM> so that the inside of the housing <NUM> is properly sealed off once the window <NUM> and the window locking mechanism <NUM> is in the closed position (c. The hinge <NUM> may be fixed to the opening <NUM> or it may be fixed to the housing <NUM>.

Turning now to <FIG> a cross-sectional view of the inversion unit <NUM> cut through line VI - VI of <FIG>. <FIG> illustrates an inner space of the housing <NUM> in which inner space the inner reel <NUM> is arranged.

The invention has now been described referring to an embodiment according to the <FIG>. It is however possible to change and vary some aspects of the invention within the scope of the claims.

The unlocked position and the open position of the window locking mechanism may be regarded as the same, both positions; the unlocked and open position relate to positions in which the window <NUM> can be moved out of the way so that the inside of the housing can be accessed.

The hinge <NUM> may be connected to an edge of the opening <NUM> or the housing <NUM> and it may be fixedly and rigidly connected to one or both of the edge of the opening <NUM> and the housing <NUM>.

The above used term bayonet catch may refer to a bayonet mechanism or a bayonet lock.

Further the motion link assembly <NUM> is shown to have four motion link elements <NUM>, two on each side of the opening <NUM>, and the matching projection assembly <NUM> has likewise four projections <NUM>, two on each side of the opening <NUM>. Any other symmetric or non-symmetric disposition of projections and motion links may however be used and considered feasible for the invention as explained above.

Claim 1:
An inversion unit comprising a housing (<NUM>), a reel (<NUM>) for a liner partially arranged in the housing (<NUM>), and a base assembly (<NUM>), the housing (<NUM>) being arranged on the base assembly (<NUM>), said housing (<NUM>) comprising a gas inlet (<NUM>), an outlet (<NUM>) for the liner, an opening (<NUM>) comprising a window (<NUM>) and a window locking mechanism (<NUM>) for closing and opening the window (<NUM>), said window locking mechanism (<NUM>) being designed to be manoeuvred into an open position in which the window (<NUM>) is open and unlocked and a closed position in which the window (<NUM>) is closed and locked, characterized in that the window locking mechanism (<NUM>) is designed as a bayonet catch and comprises a motion link assembly (<NUM>) and a matching projection assembly (<NUM>), the window locking mechanism (<NUM>) further comprising a handle (<NUM>) and a hinge (<NUM>), the handle (<NUM>) being pivotably connected to the hinge (<NUM>) wherein one of the motion link assembly (<NUM>) or the matching projection assembly (<NUM>) is arranged on the window (<NUM>) and the other of the matching projection assembly (<NUM>) or the motion link assembly (<NUM>) is arranged on an edge of the opening (<NUM>), wherein the hinge (<NUM>) is arranged on the housing (<NUM>) and wherein the handle (<NUM>) is pivotably connected to the window (<NUM>) so that the window (<NUM>) can be easily opened and closed in a bayonet catch manner using the handle (<NUM>).