D. M. VINCENT MATERIALS MIXER June 17, 1969 Filed Oct. 16, 1967 /N 1/5 N 702 DA E/QELL M. V/A/CENT hAee/s M56, Russ 5L1. 6: KEEN June 17, 1969 D. M. VINCENT MATERIALS MIXER Filed Oct. 16, 1967 N 1 EN 702 DAQEELL M VIA/GENT 5 Y ///5 A 7'7'0EA/EY5 fizzle/5, Mac/y R0555 3: Kse/v United States Patent 3,450,392 MATERIALS MIXER Darrell M. Vincent, Glendora, Calif., assignor to Automatic Sprinkler Corporation of America, Cleveland,
Ohio, a corporation of Ohio Filed Oct. 16, 1967, Ser. No. 675,563 Int. Cl. B01f 7/08; B28c /14; F161 21/02 US. Cl. 259178 9 Claims ABSTRACT OF THE DISCLOSURE A materials mixer including spiral mixer blades individually and removably mounted on a drive shaft in a mixing tank, with self-adjusting packing for the ends of the shaft.
Background of the invention Materials mixers have heretofore been used which are especially adapted for mixing materials of a semifluid or viscous nature and which employ blade assemblies with spiral-shaped blades fixedly mounted on a drive shaft in a mixing tank. Unfortunately, such mixers are not entirely satisfactory in operation and upon malfunction or breakage of any part of the spiral blade assemblies, require replacement of the entire assembly including the drive shaft. In addition, difiiculty has been encountered in aligning and maintaining a fluid tight seal around the drive shaft in the mixing tanks of such mixers.
Devices of the foregoing general nature and purpose are shown, for example, in the following United States Patents: I. A. Rice, Patent No. 1,769,309, dated July 1, 1930; R. E. Swarthout, Patent No. 3,043,571, dated July 10, 1962.
The present invention provides a material mixing machine, particularly suitable for thorough mixing of semifluid mixtures such as plaster, mortar, or concrete but which can also be used for dry mixtures. The machine preferably incorporates a partially cylindrical mixing tank open at the upper end thereof for insertion of materials to be mixed and which tank is rotatable to permit utilization of a discharge spout for mixed material normally adjacent the top of the tank.
A spiral mixing assembly including a plurality of spirally shaped mixing blades is mounted on a drive shaft by attachment means which permit relatively easy adjustment of ends of the blades, easy mounting and removal of the blades, and individual servicing and replacement of the blades and support arms therefor.
Self adjusting and aligning packing means for the drive shaft control axial compression on packing rings surrounding the ends of the shaft, automatically compensate for wear of the packing rings, and maintain substantially uniform compression on and sealing of the packing rings around the drive shaft. Details of the packing means will be more fully described with reference to the accompanying drawings. Briefly, however, it includes a sleeve construction bearing axially against confined split packing rings, and a floating pressure plate resiliently transmitting uniform axial compressive forces to the packing rings through the sleeve construction, the result being uniform packing wear and sealing forces around the shaft ends.
Additional objects and advantages of the present invention will be more readily apparent from the following detailed description, when taken together with the acompanying drawings in which:
FIG. 1 is a side elevational view, partly in section, of a mixer utilizing the device of the present invention;
FIG. 2 is a fragmentary sectional view taken on line 22 of FIG. 1, looking in the direction of the mixer rear;
FIG. 3 is a sectional view taken on line 33 of FIG. 1, looking in the direction of the mixer front;
FIG. 4 is a fragmentary elevational view, partly in section, of a blade drive shaft and blade support arm connecting means, and additionally showing connections of blade ends and an end wiper blade;
FIG. 5 is a sectional view taken on line 5-5 of FIG. 4.
FIG. 6 is an enlarged fragmentary elevational view, partly in section of a blade support arm and shaft connecting clamp therefor;
FIG. 7 is a sectional view taken on line 77 of FIG. 1;
FIG. 8 is a sectional view taken on line 88 of FIG. 7;
FIG. 9 is a perspective view of one portion of a split sleeve adapted for coaction with drive shaft support packing means; and
FIG. 10 is a side elevational view of a split packing ring as used in the device.
Referring now in more detail to the drawings, the invention includes a carriage or trailer generally designated 20, including a bed frame member 22 having a forward end frame 24, the lower end 26 of which constitutes a support leg for the machine. The upper end of end frame 24 is operatively secured to a bearing bracket, generally indicated at 28, carrying a trunnion bearing 29. A real frame member 30 is also secured at its lower end to bed frame member 22 with its upper end operatively secured to a bearing bracket, generally designated at 32, carrying a similar bearing.
A power drive unit 34, shown in dotted lines, is mounted in any appropriate manner on carriage 20, and an appropriate housing is provided at 36.
A wheel and support unit is generally shown at 38 and includes cantilever springs 40 secured on bed frame 22, an axle 42 having bed plates 44 attached thereto, and spring clamps 48 operatively securing Wheels 50 to the axle.
A connector unit 52 is secured to the output shaft of the power unit and to the end of a spiral blade drive shaft 53, by "bolts 54 and set screw 56. Bearing means may be incorporated in the connector unit.
A mixing tank assembly is generally designated 58 and includes a partially cylindrical tank 60 having ends 60a and 60b and an open top 62 with radially separated entrance and pour spouts 64 and 68 leading into and from opposite sides thereof. Bars 66, or the like, extend longitudinally along the entrance spout 64 for supporting bags of materials while the bags are opened and the materials emptied into the tank. The mixing tank 60 is mounted for rotation by the trunnion bearings 29 and is movable between a load position with the open top facing upward and a dump position with the pour spout 68 adjacent or below the mid-plane of the tank. A handle H is connected to the tank to permit an operator to manually swing the tank 60 between the load and dump posit-ions as desired with stop means, generally indicated at 70, serving to limit rotation of the tank.
Important features of the present invention reside in the configuration of the drive shaft 53 and in the mountings for blade support arms and blades thereon. In particular, as to the drive shaft 53, it has a central portion 78 of square cross section and cylindrical end portions 74 which extend into and through packing cups or sleeves 76 and 77, and are supported by ball bearing units 33 (see FIG. 7).
As to the mountings and blades in the illustrated form of the mixer, eight (8) radially extending blade support arms 80, 82, 84, 86, 90, 92, and 94 are individually and removably secured at their inner ends to the portion 78 of the shaft by five (5) split arm-mount clamps 96, 98, 100, 102, and 104. In this regard, each arm-mount clamp consists of mating L-shaped halves each having outwardly extending flanges or arms 106 with bores (not shown) extending therethrough. The bores are adapted 3 to accommodate securing bolt and nut assemblies 108 which releasably secure the clamp halves together on the shaft 53. Generally speaking, the inner end of each blade support arm is secured to a half of an associated clamp, as by welding or the like.
More particularly, the arms 80 and 82 are bent and secured at their inner ends to different halves of clamp 96. The clamp 96, in turn, is adapted for connection to the front end portion of the drive shaft 53 such that the arms 80 and 82 extend axially along the shaft toward and to some extent over the packing cup 77 and then diametrically therefrom along the end wall 60b of the mixing tank 60.
The arms 84 and 86 are bent in a similar manner and are secured to the halves of the clamp 98. The clamp 98 is adapted for connection to the rear end portion of the shaft 53 such that the arms 84 and 86 extend axially along the shaft toward and to some extent over the packing cup 76 and diametrically therefrom along the end wall 60a of the mixing tank 60. The angular orientation of the arms 84 and 86 relative to the shaft 53 is the same as that of the arms 80 and 82 relative to the shaft.
The remaining arms are substantailly straight and extend radially toward the inner cylindrical wall of the mixing tank. In particular, arms 88 and 90 are secured at their inner ends to opposite and different halves of the clamp 100 for connection to the center of the shaft 53 oriented at 90 relative to the arms 80 and 82, and arms 92 and 94 are secured to opposite halves of diiferent clamps 102 and 104 for connection to the shaft between the clamps 96 and 100 and 98 and 100, respectively.
In the mixer of the present invention, the blade support arms are designed to releasably support two pairs of spiral blades 110a, b and 112a, b within the mixing tank 60. To this end, each arm end has a flat pad 114 secured thereto with an opening therethrough for receiving bolt and nut assemblies 116 to releasably secure the blades thereto.
The spiral blades 110a, b are of relatively small radial dimension and are of left-hand and right-hand thread respectively, while the spiral blades 112a, b are of relatively large radial dimension and are of right-hand and left-hand thread respectively. The front and rear ends of the spiral blades 12a, 1) are releasably secured to the pads connected to the ends of the arms 84 and 88, and 90 and 80, respectively, by nut and bolt assemblies 116 while pads secured to the ends of the arms 94 and 92 are connected in a like manner to mid portions of the spiral blades 112a and 11212 as illustrated most clearly in FIG. 1.
The ends of the inner spiral blade 110a are secured by nut and bolt assemblies 116 to the pad 114 connected to the end of the arm 86 and similarly to a second pad 114a secured to the arm 88 inward of its pad 114. The ends of the spiral blade 11% are secured in a like manner to a second pad 114!) on the arm 90 and to the pad 114 connected to the end of the arm 82. Corresponding inner and outer spiral blades are also connected together at their crossover points by tie rods 117 as illustrated most clearly in FIG. 2.
Thus secured, the inner left-hand spiral blade 110a curls within the outer right-hand spiral blade 112a while the inner right-hand spiral blade 110b curls within the outer left-hand spiral blade 112b- With the spiral mixing blades thus arranged on the drive shaft 53, a turning of the shaft effects a rapid and complete churning and mixing of the material in the tank by drawing material from the ends of the tank along the cylindrical inner walls thereof toward the center of the tank, and then axially along the shaft towards front and rear walls 60b and 60a of the tank.
In addition to the two sets of spiral blades, the mixing assembly for the mixer of the present invention includes a pair of scraperblades 118 and 119 for clearing the end walls 60a and 60b upon turning of the drive shaft 53. The scraper blades 118 and 119 are secured to the arms and 84, respectively, by nut and bolt assemblies 120 passing through extensions 122 of the pads 114 connected to the arms and through secondary pads 124 secured to the arms inward of the pads 114. As illustrated most clearly in FIG. 5, the extensions 122 and the pads 124 are inclined toward the end walls of the mixing tank such that the scraper blades when secured thereto extend at an angle to the end walls. Also, the tips of the scraper blades are spaced approximately one-eighth inch from the end walls to facilitate efficient wiping of the end walls with rotation of the drive shaft 53.
From the foregoing description, it is appreciated that the mixing blade assembly of the present invention is designed for easy attachment to the drive shaft 53 and for simple and rapid removal of the individual component parts as servicing or change of shape of spiral mixing blade is desired. This is accomplished by employing the split clamps and nut and bolt connecting assemblies 108 which permit ready disconnection of the support arms from the shaft. The split clamp and nut and bolt connection assemblies also permit the support arms to be shifted axially along the drive shaft 53 to modify slightly the spiral configuration of the blades and to adapt to different spiral configurations of different blade assemblies which may be included in the mixer of the present invention.
It is of prime importance to the efficient operation of the mixer of the present invention that the drive shaft 53 be maintained in axial alignment with the bearings 33 and that a fluid-type seal be maintained at all times around the forward and rear ends of the drive shaft. To accomplish this, the present invention includes a novel self-adjusting packing for the shaft 53 which is illustrated most clearly in FIGS. 710.
The present self-adjusting packing represents a significant improvement over prior manually adjustable packings. Previously, to control the axial compression on packing rings around a shaft, adjustable packings employed a bolt connected to a casting bearing against the packing rings. By tightening the bolt, the compression on the packing rings was maintained to create a seal around the shaft within a packing box.
In the present invention the bolt is replaced with a spring arrangement which is self-adjusting to compensate for wear of the packing rings, and which maintains substantially uniform compression on the rings around the shaft.
Referring particularly to FIG. 7 of the drawings, which is a sectional view taken along line 77 of FIG. 1 at the tongue end of the mixer, the tank wall 60b is fragmentarily shown having an opening 126 therein. A cylindrical end portion 74b of the shaft 53 extends through the opening 126 and is rotatably mounted in the ball bearing unit 33 carried in the end of a housing 128, the trunnion bearing 29 surrounding a neck of the housing. The shaft is axially positioned relative to the hearing by a collar 132 having a set screw 134 therein. The bearing is held in a socket of the neck of the housing by cap screws 136 passing through a washer 138 into the neck as illustrated. The housing 128, in turn, is secured to the end wall '60]; of the tank by nuts on bolts 140 passing through the end wall and through flanges 142 extending from a side of the housing.
Within the housing 128, the previously referred to packing cup 77 is seated in the opening 126 and extends into the tank 60 and is welded at an external flange 144. A plurality of split packing rings 146 of suitable material and preferably having angular end portions 148 (FIG. 10) are mounted in the cup 76, preferably with grease on the exterior of the rings. A circular packing follower 150 coacts with an interiorly directed flange 77a, or the like, to properly maintain the packing rings in the cup.
A split sleeve 152, having internal flanges 154 on its rear end and external flanges 156 on its forward end is adapted to fit around shaft end 74b with the internal flanges bearing against the outermost packing ring in response to forces exerted on the sleeve by a pressure plate 158. In this regard, the pressure plate 158 is mounted within the housing 128 against the forward end of the split sleeve 152 and is a substantially diamond shape having upper and lower bores 160 and 162 and a central opening 164. The central opening 164 is adapted to loosely receive the shaft end 74b while the bores 160 and 162 are equally spaced from the central opening and are adapted to loosely receive carriage bolts 166 of self-adjusting spring assemblies 168 and 170.
In addition to the carriage bolts, each of the assemblies 168 and 170 includes a coil spring 171 and an internally threaded sleeve 172 having an enlarged end 174 for hand turning the sleeve on the carriage bolt. The coil spring 171 is partially compressed, extends around the sleeve 172 and is captured between a washer 176 bearing against the enlarged end 174 and the forward face of the pressure plate 158. Thus arranged, the forces developed by springs 171 of the assemblies 168 and 170 on the pressure plate 158 may be set by turning the sleeves 172 and once established cause the plate to continuously exert axial forces on the packing rings through the sleeve 152.
In this regard, it is an important feature of the improved self-adjustable packing that the pressure plate 158 is free floating. That is, the plate is not fixed to either the springs, or the packings, or the sleeve pressing on same. Therefore, the plate 158 continuously exerts uniform axial forces on the split sleeve 152 and hence on the packing rings despite minor inequalities in the spring forces developed by the individual coil springs, nonuniformities in the wear or axial dimensions of the packing rings, or misalignment of the packing rings and shaft axes. Any one of these problems would in the prior form of adjustable packing produce nonuniform axial forces on the packing rings and result in nonuniform packing wear and nonuniform sealig around the shaft. Moreover, as the packing rings wear, and hence contract in axial dimension, the coil springs acting on the pressure plate expand axially from their compressed condition to automatically compensate for the wear of the rings and thereby maintain uniform sealing around the shaft over long periods of time. This also is in direct contrast to the manual adjustable unit which required continuous checking and adjustment to insure that a proper seal was maintained.
Other important features of the self-adjusting packing reside in the ease with which it may be assembled and with which worn packing rings may be replaced without removal of the shaft 53. This is due primarily to the split nature of the packing rings and the sleeve 152 which may be assembled around and removed from the shaft without disturbing the shaft.
While a preferred form of the present invention has been described in detail herein, it is appreciated that changes and modifications may be made in the illustrated form without departing from the spirit of the invention. Accordingly, it is intended that the present invention be limited in scope only by the terms of the following claims.
1. A materials mixer comprising:
a mixing tank;
a drive shaft rotatably mounted in said tank;
a mixing blade assembly secured to said shaft; and
support means for ends of said shaft at the longitudinal ends of said tank, said support means including selfaligning and adjusting packing means resiliently urged inwardly with respect to said shaft to maintain substantially equal and self-aligning support and packing for the shaft ends, said self-aligning and self-adjusting packing means including a tubular packing cup extending into the interior of said mixing tank to receive an end of said shaft, a plurality of packing rings forming a packing assembly in said cup surrounding the shaft end and being restricted at an end of said cup, and means resiliently axially urging said packing rings with compressive force into said cup from a position externally of said cup.
2. The mixer of claim 1 further comprising:
a sleeve surrounding said shaft and externally of said cup, said sleeve being in engagement with an outer end of said packing assembly; and
wherein said means resiliently urging said packing rings bears on the exterior of said sleeve.
3. The mixer of claim 2 comprising:
a floating pressure plate in engagement with an outer end of said sleeve;
means movably mounting said plate to exert resilient axial compressive forces against said sleeve; and
wherein said means resiliently urging said packing rings bears against said plate.
4. The mixer of claim 3 further comprising:
a plurality of bolt means fixed relative to an end of said tank;
said pressure plate having openings therethrough, said bolt [means extending loosely through said openings;
internally screw-threaded adjustment sleeves on said bolt means; and
resilient coil springs surrounding said adjustment sleeves and having one end thereof in contact with the exterior of said pressure plate and the other end thereof being in engagement with the said adjustment sleeves whereby tightening of said adjustment sleeves acts to compress said springs thereby creating pressure on said pressure plate and axial pressure on said sleeve and thereby on said packing assembly.
5. In a machine having a rotatable support shaft supported in bearings, a self-aligning and adjusting shaft sealing means surrounding at least a portion of said shaft, said sealing means including:
confined packing means about said shaft;
means restraining said packing means about said shaft for sealing engagement;
packing compression means resiliently inwardly urged against said packing means;
pressure means against and in free floating relationship to said packing compression means; and
resilient means applying adjustable pressure against said pressure means.
6. The combination of claim 5 wherein:
said packing compression means comprises a sleeve around said shaft;
said pressure means comprises a plate; and
said resilient means comprises springs bearing on said plate at points spaced equally from said shaft.
7. The combination of claim 6 wherein:
saici1 plate includes openings equally spaced from said s aft;
said combination includes fixed bolt means extending loosely through said openings;
said springs are coil springs around said bolt means; and
said combination includes internally threaded adjustment sleeves for said bolt means for compressing said coil springs.
8. A material mixer comprising:
a mixing tank having front and rear closed end walls;
a drive shaft;
means on said end walls mounting said drive shaft for rotation on its longitudinal axis within said tank;
first, second, and third removable clamp means secured on said shaft, said first and second clamp means being adjacent said front and rear end walls respectively and said third clamp means being adjacent the middle of said tank;
first, second, and third pairs of arms, said first and second pairs of arms being secured to diametrically opposite sides of said first and second clamp means respectively with corresponding arms extending in like radial directions from said shaft, said third pair of arms being secured to diametrically opposite sides of said third clamp means to extend radially from said shaft;
relatively large rightand left-hand spiral blades;
relatively small rightand left-hand spiral blades; and
means for releasably securing said blades to said shaft faces of said front and rear end walls upon turning for turning therewith in said tank with said relatively of said shaft; and small rightand left-hand spiral blades within said means on opposite arms in said first and second pairs relatively large leftand right-hand spiral blades of arms for releasably securing said scraper blades respectively, said means including means on opposite 5 to said shaft to extend normal thereto and closely ones of said first pair of arms for releasably conalong said front and rear walls respectively. necting end portions of said relatively large left-hand spiral blade and said relatively small right-hand spiral References Cited blade respectively to said shaft, means on one of UNITED STATES PATENTS said third pair of arms for releasably connecting 10 opposite end portions of said relatively large left- 601,614 3/1898 lf 277106 hand spiral blade and said relatively small right-hand 958,421 5/ 1910 Mcnvnd X spiral blade to said shaft, means on opposite ones of 1,030,250 6/1912 Y 259-478 X said second pair of arms for releasably connecting 1,630,790 5/ 1927 Esslck 259-178 end portions of said relatively large right-hand spiral 15 1:811719 6/1931 1911118011 blade and said relatively small left-hand spiral blade 1,769309 7/ 1930 Rlce X respectively to said shaft, and means on the other 2,137,328 11/1938 Bissell 259-1O7X of said third pair of arms for releasably connecting 2,608,424 8/1952 Everett opposite end portions of said relatively large rightand spiral blade and said relatively small left-hand spiral blade to said shaft. 9. The material mixer of claim 8 further including: elongated flat scraper blades for clearing the inner sur- 2S9l10; 277--106 20 ROBERT W. JENKINS, Primary Examiner.
US. Cl. X.R.