WO2001054876A1

WO2001054876A1 - Rotary mixer

Info

Publication number: WO2001054876A1
Application number: PCT/ZA2001/000007
Authority: WO
Inventors: Gerhardus Petrus Fritz
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-01-28
Filing date: 2001-01-26
Publication date: 2001-08-02
Anticipated expiration: 2002-07-28
Also published as: AU4371801A

Abstract

A wheelbarrow type rotary mixer (10) comprises a mixing vessel (12) encompassing a mixing zone (14) and a freely rotatably mounted mixing rotor (16) fitted to rotate within the mixing zone (14). The vessel (12) is mounted to rotate about an upright axis (18) and rests on rollers (20) each fitted to a support frame (22), in turn supported by a wheelbarrow shaped carrier (24). The axis of rotation (30) of the rotor (16) stands at an acute inner angle (32) with respect to the axis (18) of the vessel (12). The rotor (16) is fitted with a plurality of symmetrically spaced mixing arms (34). The vessel (16) is manually driven by means of a circumferentially extending handle (58). The support frame (22) is swivellably connected to the carrier (24) towards its front end. At the other end it is secured to the carrier (24) by means of a swivelably mounted restraining arm (74). Discharge of mixed contents is promoted by the frame (22) and thus vessel (16) swivelling forward beyond the angle of carrier swivelling once performing a wheelbarrow fashion discharging action. The extent of additional forward swivelling is curtailed by the restraining arm (74) limiting the possiblity of undesired tilting of the support frame relative to the carrier (24).

Description

(1) TITLE OF THE INVENTION

ROTARY MIXER

(2) CROSS REFERENCED APPLICATIONS

GB 2336116

GB 2206061

GB 2181069 GB 2108002

US 4042222

US 5403086

JP 10148033

JP 9314542 ZA 96/5546

ZA 78/0259

(3) BACKGROUND TO THE INVENTION

If is often necessary to mix substances by way of a batch process. Typically the mixing of concrete, mortar or the like comes to mind. When mixing is done under conditions where the view of the charge during mixing is obscured the mixing process must often be temporarily halted to assess the extent of mixing. If the various components of the charge have to be pre-mixed or even only pre-measured and then charged to the mixing equipment, it results in a cumbersome process. The mixing of a charge is often done at a location remote from where the mixture is required thus involving transportation to the desired location. As mixing is often done under conditions where equipment is exposed to the elements of nature complicated mechanisms tend to break down easily. The less complicated the equipment the better its chance of surviving rough treatment. In this regard the equipment is often required to be manually driven. It is an object of this invention to, amongst others, address these issues. (4) FIELD OF THE INVENTION

This invention relates to a mixer for mixing a mixture of one or more particulate substances in the appropriate case also involving liquid. Although not so limited the mixer of the invention finds useful application in the mixing of cementitious and the like charges.

(5) PRIOR ART DESCRIPTION AND DISCLOSURES

Mobile rotary concrete or the like mixers are known to the applicant. These types of mixers make use of rotating drums mounted to rotate about axes slanted off the horizontal thus causing its charge to gravitationally fall from an elevated position back to the lower side wall of the drum during its rotation. When manually operated the drums are often driven by means of a crank handle rotating the drum via appropriate gearing. Mixers of this kind have the disadvantage of not making provision for measuring the extent of the various charge components in the process of combining them into the charge. The various charge components consequently have to be pre-measured and batched and then added to the mixer if individually so charged. A further disadvantage is found in requiring their intermittent stoppage for inspection of the charge during mixing. Once a mixer has been used it often requires thorough cleaning. Because of their constricted inlets rotating drum type mixers are often difficult to clean after use. Another kind of mixer is the pan type making use of a rotating pan with separately driven equipment performing the mixing function. As these mixers require powerful drive mechanisms they are normally permanently installed.

(6) BRIEF DESCRIPTION OF THE DRAWING

The invention is now described, by way of example, with reference to the accompanying drawings. In the drawings

Figure 1 shows in partly cut away side elevation a mixer, according to the invention, in the form of a wheelbarrow-type concrete or the like mixer,

Figure 2 shows in plan view the support of the vessel of the mixer, Figure 3 shows in three-dimensional partly cut away detail the mixing vessel of the mixer as fitted to its support,

Figure 4 shows the mixing vessel in plan view,

Figure 5 shows in side elevation the mixer as containing substance desired be mixed while in broken lines showing the connection of a drive source for driving the vessel, and

Figure 6 shows in side elevation the discharging action of the mixer inclusive of, in broken lines, the action of the quick release connection between the vessel and the drive source on such discharging action.

(7) DETAILED DESCRIPTION OF THE DRAWINGS

Referring to the drawings a rotary mixer in the form of a wheelbarrow type rotary concrete mixer is generally indicated by reference numeral 10.

The mixer 10 comprises a rotatably mounted overhead chargable mixing vessel 12 encompassing a mixing zone 14 and a freely rotatably mounted mixing rotor 16 fitted to rotate within the mixing zone 14. The vessel 12 is mounted to rotate about an upright axis 18 by resting in a support providing a vessel bed defined by a number of circumferential ly spaced rollers 20 each fitted to a support frame 22. The frame 22 is also fitted with a bearing-carrying shaft-receiving socket 23 along which a shaft 25 fitted to the bottom of the vessel and extending along the axis 18, is rotatably mounted. The frame 22 is, in turn supported by a wheelbarrow shaped carrier 24 that renders the mixer 10 mobile. The vessel 12 is inverted frusto-conically formed with the mixing zone 14 extending between a small bottom 26 and a large overhead charging and discharging opening 28.

The rotor 16 is mounted to rotate about an axis 30 extending at a slanted acute inner angle 32 with respect to the axis 18 of the vessel 12. The rotor 16 is fitted with a plurality of mixing arms 34 that are symmetrically spaced about the rotor axis 30. The angle 32 is suitably selected to cause the rotor 16 to promote the impartation of a slow but effective agitating motion through mixture being moved along in conjunction with the vessel 12 during its rotation in response to consecutive arms 34 being urged along by mixture passing along the rotor 16. Typically the angle 32 can be in the order of 45 degrees although not so limited. Mixture is thus caused to become both radially and vertically displaced within the mixing zone 14. The angle 32 and the outside profile 36 of the arms 34 are selected to ensure that the arms 34 sweep in close vicinity past the adjacent inner wall section as consisting of an effective length of a combination of both the inwardly sloping side wall 38 and the bottom 26 of the vessel 12 on rotation of the rotor 16 to limit the formation of a non-mixing dead zone inside the vessel 12.

The support frame 22 presents two commonly rooted opposing forwardly-spaced roller- carrying-arms 40 each carrying a roller 20.1 mounted at the correct angle to run smoothly against the outer sidewall of the vessel 12. A rearward spaced roller-carrying-arm 44 extends rearward from the arms 40 and is also fitted with a roller 20.2. The arm 44 extends though a suitably curved section 48 to cause its end 50 to be off centre with respect to the central axis of the frame 22 situated overhead the opening 28. The rotor 16 is conventionally rotatably mounted to the inner end 52 of the arm 44 of which the curvature of the section 48 ensures that the axis 30 forms the desired angle 32 with the axis 18 of the vessel 12. In the case where the shaft 25 of the vessel 12 is fitted with a coupling 54, as shown in figures 5 and 6, to enable its driving from a drive source 56, the arm 44 extends somewhat off centre from the arms 40, as shown in figure 2, to accommodate the socket 23. In such case the drive source 56 is selected and arranged to cause the vessel 16 to rotate at a speed that limits the exertion of centrifugal force on substance being mixed in the vessel 16.

While the mixer 10 can be arranged to cause the vessel 16 to be driven from a drive source 56 the invention also makes provision for its manual rotation by means of manually manipulable rotating means in the form of a circumferentially extending handle 58 fitted by means of connecting pieces 59 to and towards the upper lip 12.1 of the vessel 16. In making provision for being externally driven and referring more particularly to figures 5 and 6, the coupling 54 is provided by a quick engagement and release forked coupler 60 fitted to the shaft 25 that is configured to engage with a complementary formed upwardly facing coupler 62 provided at the leading end of a drive shaft 64 extending from the drive source 56. Disengagement of the coupling 54 is automatically achieved when the carrier 24 is tilted forward, as shown in figure 6. Re-engagement is achieved on aligning the couplers 60 and 62 when the carrier 24 is lowered.

The carrier 24 renders the mixer manually mobile by providing conventional handles 66 and a nose wheel 68. To discharge mixed substance from the vessel 12 the carrier 24 is simple conventionally tilted forward about its nose frame 70, as shown in figure 6. This action results in a conventional wheelbarrow type discharge of mixture. To facilitate discharge the support frame 22 is swivelably connected to the carrier 24 via its arms 40 by means of inter- swivellable connecting pieces 72. The arm 44 is secured to the carrier 24 by means of a swivelably mounted restraining arm 74 extending freely swivelably between a support frame connecting lobe 76 and a position of swivelling (not shown) on the carrier 24. When the mixer 10 is in its mixing condition, as shown in figure 5, the restraining arm 74 lies inactively along the arm 44 that, in turn rests against a cross member (not shown) forming part of the carrier 24. When the mixer 10 is wheelbarrow fashion tilted forward into a discharging condition, as shown in figure 6, discharging is promoted by the frame 22 and thus vessel 16 swivelling forward beyond the angle of carrier swivelling about an axis extending through the pieces 72. The extent of additional forward swivelling is curtailed by the effect of the restraining arm 74 limiting the possibility of undesired tilting of the support frame 22 relative to the carrier 24.

To facilitate in the preparation of a desired mixture composition the vessel 12 displays a volumetric graduation 76 along its inner wall.

The mixer 10 is thus used to easily and accurately under its ordinary conditions of use prepare a homogeneous mixture 80 from a charge of adequate consistency. This is achieved by the rotor 16 being urged to rotate about its axis 30 in response to impingement of mixture 80 passing along the rotor 30 on the arms 34 once the vessel 12 is rotated. Typically a conventional cementitious mixture can be prepared from a standard charge. The use of the mixer 10 in naturally not limited to such charges only so long as the requirement of the charge being of adequate consistency to be moved along in conjunction with the vessel 12 is met. Once as suitable charge is located in the vessel 12, or even during addition of the components making up the charge to the vessel 12, mixing is commenced with by manually rotating the vessel 12 by means of the handle 58. This is achieved by, for example, pushing the vessel 12 to rotate in the direction of arrow 82 as shown in figures 3 and 4. Alternatively the drive source 56 can be used. As the charge is caused to move along with the vessel 12 during rotation it is caused to pass along the rotor 16. Being freely rotatably mounted the arms 34 of the rotor 16 are thus urged to rotate in the direction of arrow 84, as shown in figure 3, in response to impingement of charge on the arms 34. Proper mixing is achieved as mixture passing along the rotor 16 is caused to become displaced both radially and vertically within the mixing zone 14 owing to the slanted angle of rotation of the rotor 16. Once the mixture is desirably mixed it is simply wheelbarrow fashion discharged from the vessel 12, as shown in figure 6. As the carrier 24 is wheelbarrow fashion formed the mixture 80 can be deposited at any desired location by simply pushing the mixer 10 to such location.

Claims

(8) CLAIMS

(1 ) A rotary mixer for mixing a mixture of one or more particulate substances comprising

an overhead chargable mixing vessel encompassing a mixing zone and being mounted to a support to enable its rotation about a suitably extending axis to cause such mixture, once charged to the mixing zone and as of adequate consistency, to be moved along in conjunction with the vessel about its axis once caused to be rotated at a rotational speed that limits the effect of centrifugal force on such mixture, and

at least one freely rotatably mounted mixing rotor extending suitably and independent of the rotational movement of the vessel into the mixing zone, at least once the mixer is ready for use, to cause it to perform an effective rotational mixing action within the mixing zone, as brought about by mixture, on being moved along in conjunction with the vessel during its rotation once the mixer is in operative use, passing along the rotor and impelling it into performing a rotational mixing action within such mixture.

(2) A rotary mixer as claimed in claim 1 in which the mixing rotor presents a plurality of mixing arms spaced about the axis of rotation of the rotor.

(3) A rotary mixer as claimed in claim 2 in which the rotor is configured and mounted to cause its mixing arms to sweep in close vicinity past at least part of the adjacent wall of the vessel on the rotor being rotated thereby to limit the formation of a dead zone inside the vessel in which substance intended to be mixed is not exposed to the action of the rotor.

(4) A rotary mixer as claimed in any one of the preceding claims in which the mixing rotor, as appropriately formed, is mounted to rotate about a suitably slanted axis with respect to the rotational axis of the vessel to promote the impartation of a slow but effective agitating motion having both radial and vertical components to mixture passing along the rotor once the mixer is in use.

(5) A rotary mixer as claimed in any one of the preceding claims in which the vessel extends inverted frusto-conical fashion between a larger charging end and a smaller bottom.

(6) A rotary mixer as claimed in claim 5 in which the support of the vessel at least comprises a bed of suitably held support rollers that engage the outside surface of the side wall of the vessel at locations that limit lateral movement between the vessel and the rollers when the vessel is rotated.

(7) A rotary mixer as claimed in any one of the preceding claims in which the vessel is mounted to be rotated about an at least substantially upright axis.

(8) A rotary mixer as claimed in any one of the preceding claims in which the vessel is fitted with manually manipulable rotating means.

(9) A rotary mixer as claimed in claim 8 in which the manually manipulable rotating means is provided by a circumferential ly extending handle fitted towards the upper lip of the vessel.

(10) A rotary mixer as claimed in any one of the preceding claims in which the vessel is arranged to be driven by means of a drive source.

(11) A rotary mixer as claimed in claim 10 in which the vessel is fitted with a quick engagement and release connector to enable its convenient releasable engagement to an appropriate drive source.

(12) A rotary mixer as claimed in any one of the preceding claims that is in the form of a manually manageable mobile unit enabling its manual shifting between desired locations.

(13) A rotary mixer as claimed in claim 12 in which the unit incorporates a wheelbarrow type support frame fitted with handles and a wheel and to which the vessel is rotatably mounted via its support, discharging of mixed substance from the vessel being achieved by conventionally wheelbarrow fashion tilting the mixer forward.

(14) A rotary mixer as claimed in claim 13 in which the support of the vessel is limitedly swivelably mounted to the wheelbarrow type support frame to enable the limited swivelling of the vessel in its discharge direction beyond the angle of tilting of the carrier thereby to promote the discharging action of the vessel.

(15) A rotary mixer as claimed in any one of the preceding claims in which the vessel displays an appropriate volumetric graduation to facilitate in the preparation of a desired mixture composition.