GB2224219A - A mixer liner - Google Patents

Abstract

A mixer liner (2) for use in apparatus including a rotary drum for mixing building materials is made of a flexible material so that it can be removed from the mixer apparatus. The liner may have apertures to accommodate mixing blades provided on the interior wall of the drum. <IMAGE>

Description

A MIXER LINER This invention relates to a mixer liner.

More especially, this invention relates to a mixer liner for use in mixer apparatus for mixing building material.

Mixer apparatus, for example rotating drum apparatus or tray apparatus with moving mixer blades, is well known in the building industry. The mixer apparatus is used for mixing building material such for example as cement, plaster or bonding. Other materials are from time to time mixed in the mixer apparatus.

A problem often occurs in the cleaning of the mixer apparatus, for example so that the mixer apparatus can take a fresh charge of the same material to be mixed, or so that the mixer apparatus can be used for mixing a different material. It often occurs that the material being mixed in the mixer apparatus has set hard and thus the mixer apparatus cannot be washed clean. This problem is especially acute when mixing bonding or when mixing cement containing a hardener because the bonding and the cement tend to set hard very rapidly. It is customary either to hit the mixer apparatus in order to break away the set mixed material, or to chiesel away the set mixed material. Workmen on site are not over careful in the way in which they hit the mixer apparatus and thus the mixer apparatus may be struck with all sorts of implements and it may be struck too hard.The result is deformation and/or breaking of various parts of the mixer apparatus.

Similarly, workmen on site are not over careful in the way in which they chiesel away the set material. The chiesel may be struck at the wrong angle so that it may puncture the mixer apparatus, or it may be struck too hard so that the result is again deformation and/or breaking of various parts of the mixer apparatus. Often the mixer apparatus is hired out and it is brought back to the hirer in an unusable condition with the set mixed material firmly stuck in the mixer apparatus. The hirer must clean the mixer apparatus before it can be re-hired out and, whilst the hirer may be more careful than workmen on site, the hirer must still resort to hitting or chiesling.

Furthermore, the time that the hirer has to spend in cleaning the mixer apparatus could clearly be better spent doing other things.

It is an aim of the present invention to obviate or reduce the above mentioned problem.

Accordingly, this invention provides a mixer liner for use in mixer apparatus for mixing building materials, which mixer liner is made of a flexible material so that it can be removed from the mixer apparatus.

Usually, the mixer liner will include aperture means for enabling the mixer liner to be supported in the mixer apparatus such that mixing blades forming part of the mixer apparatus are positioned inside the mixer liner.

The aperture means may be at least one hole for sliding over support means of at least one mixing blade in the mixer apparatus. Preferably, there are two holes for sliding over the support means of two of the mixing blades.

Preferably, the mixer liner includes gripper means for use in pulling the mixer liner out of the mixer apparatus.

Preferably, the gripper means is a pair of handles. The handles may be in the form of knobs. Other types of gripper means may however be employed.

Usually, the mixer liner will be made in one single piece. However, the mixer liner can be made in two separate pieces which can be fastened together by fastener means. The fastener means may be, for example, press studs or tie members.

Preferably, the mixer liner is made of a rubber material. The rubber material may be a natural or synthetic rubber material. The rubber material should be chosen to be durable under the conditions of use.

Other materials such for example as some plastics materials may be employed for the mixer liners if desired.

Embodiments of the invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1 shows a first mixer liner; Figure 2 shows part of a second mixer liner; Figure 3 is a side view of a rotating drum of mixer apparatus; Figure 4 shows the rotating drum of Figure 3, partially broken away to show the inside of the rotating drum; Figure 5 is a view of the inside of the rotating drum shown in Figure 3; Figure 6 is a side view of a mixer liner for use in the rotating drum shown in Figure 3; Figure 7 is a view showing the inside of the mixer liner shown in Figure 6; and Figure 8 shows the mixer liner of Figures 6 and 7 located in the rotating drum shown in Figure 3.

Referring to Figure 1, there is shown a mixer liner 2 for use in a mixing drum (not shown) of mixer apparatus (not shown) for mixing building material.

The mixer liner 2 is made of a flexible rubber material so that it can easily be removed from the mixer apparatus and cleaned separately from the mixer apparatus. Any set mixed material on the mixer liner 2 can easily be broken away from the mixer liner 2 by virtue of the fact that the mixer liner 2 is flexible. Once the mixer liner 2 is clean, it can be reinserted into the mixer apparatus.

Alternatively, a new mixer liner 2 may be inserted into the mixer apparatus. Further, if desired, the mixer liner 2 can be flexed whilst it is still inside the mixing drum to break away any set mixed material.

The mixer liner 2 is generally cylindrical as shown and it has a top opening 4 through which the material to be mixed is inserted. The mixer liner 2 has a partconical portion 6 which extends into a parallel sided body portion 8. The body portion 8 is provided with aperture means in the form of a pair of slots 10 for fitting over a pair of mixing blades not shown in the mixing drum of the mixer apparatus. The slots 10 are provided with transverse portions 12 as shown and the transverse portions 12 have members 14 as shown. The transverse portions 12 and the members 14 may be used to secure the mixer liner 2 in position at the base of the mixing blades, for example on support members (not shown) for the mixing blades.

The slots 10 should preferably be as thin as possible to stop the material being mixed in the mixer apparatus from getting behind the mixer liner 2.

Referring now to Figure 2, there is shown a mixer liner 2 in which similar parts as in Figure 1 have been given the same reference numerals and their precise construction and operation will not again be given. In Figure 2, the mixer liner 2 is such that the slots 10 are replaced by aperture means in the form of a pair of holes 16 for fitting over the mixer blades.

In Figure 2, the mixer liner 2 is also provided with gripper means in the form of a pair of knobs 18. The knobs 18 project inwardly of the mixer liner 2 and they help the mixer liner 2 to be gripped when it is necessary to pull the mixer liner 2 out of the mixer apparatus.

Referring now to Figures 3 to 7, there is shown a rotating mixing drum 20 forming part of mixer apparatus.

The drum 20 has a base 22 and a front 24 which is provided with an opening (not shown) for charging the drum 20 with material to be mixed and for removing the mixed material from the drum 20. As shown in Figure 4, the drum 20 is provided with a pair of blades 26 which are fixed to the sides of the drum 20 and which rotate with the drum 20. As shown most clearly in Figure 5, the blades 26 are mounted on support means 28 which extend from the wall of the drum 20. Figure 5 also shows that the base 22 of the drum 20 has a central hollow portion 30 for housing a motor 32 (see Figure 3). The motor 32 rotates the drum 20. Because the drum 20 is basically of a standard construction, further details of the drum 20 have not been given.

Figure 6 shows a mixer liner 34 for the drum 20. The mixer liner 34 is basically of the same general shape as the drum 20. The mixer liner 34 is provided with a lip 36 for fitting over the rim of the front 24 of the drum 20. The mixer liner 34 is provided with aperture means in the form of a pair of slots 38. As shown in Figure 7, the mixer liner 34 is also provided with gripper means in the form of a pair of knobs 40 which act as handles and which enable the mixer liner 34 easily to be pulled out of the drum 20.

When it is desired to insert the mixer liner 34 in the drum 20, the blades 26 are removed from their support means 28. This is usually simply effected by undoing a nut for each blade 26. The mixer liner 34 can then be inserted into the drum 20 with the slots 34 fitting over the support means 28. Then the blades 26 can be repositioned on the support means 28 and the nuts (not shown) screwed back on to the support means 28 to locate the blades 26 in position on the support means 28. The reverse procedure is followed to remove the mixer liner 34 from the drum 20. Figure 8 shows the mixer liner 34 in position in the drum 20.

As shown in Figure 8, the mixer liner 34 may be shaped to accommodate the hollow portion 30 or it may just conform to shape over the hollow portion 30.

It is to be appreciated that the embodiments of the invention described above with reference to the accompanying drawings have been given by way of example only and that modifications may be effected. Thus, for example, the mixer liner 2 may be formed in two parts which can be joined together, for example along a longitudinal line, by fastener means such for example as press studs, tie members or clips. A two part mixer liner may be easier to get in and out of the mixer apparatus. Instead of the mixer apparatus having a rotating drum 20 as illustrated in Figure 3, the mixer apparatus may be in the form of a tray-like member having a pair of moving blades or paddles which may reciprocate inside the tray-like member.

Claims (11)

1. A mixer liner for use in mixer apparatus for mixing building materials, which mixer liner is made of a flexible material so that it can be removed from the mixer apparatus.

2. A mixer liner according to claim 1 and including aperture means for enabling the mixer liner to be supported in the mixer apparatus such that mixing blades forming part of the mixer apparatus are positioned inside the mixer liner.

3. A mixer liner according to claim 2 in which the aperture means is at least one hole for sliding over support means of at least one mixing blade in the mixer apparatus.

4. A mixer liner according to claim 3 in which there are two holes for sliding over the support means of the two mixing blades.

5. A mixer liner according to any one of the preceding claims and including gripper means for use in pulling the mixer liner out of the mixer apparatus.

6. A mixer liner according to claim 5 in which the gripper means is a pair of handles.

7. A mixer liner according to any one of the preceding claims and which is in one single piece.

8. A mixer liner according to any one of claims 1 to 6 and which is in two separate pieces which can be fastened together by fastener means.

9. A mixer liner according to claim 8 in which the fastener means are press studs or tie members.

10. A mixer liner according to any one of the preceding claims in which the flexible material is a rubber material.

11. A mixer liner substantially as herein described with reference to the accompanying drawings.