US2270628A - Concrete mixer - Google Patents

Description

Jan. 20, 1942- J. H. FITZGERALD CONCRETE MIXER Filed April 2, 1941 3 Sheets-Sheet l g N N a m\ E a R E Q I\ mm mm *m w we 3 I m g mm s mm m a um mm 3 Q A4 a w n 2 2 a E i \m w a i Q Jan. 20, 1942. J. H. FITZGERALD CONCRETE MIXER 3 Sheets$heet 2 Filed April 2, 1941 mlllllllllllllllllllllllllHI|Hlllllllllllllllllllllllll fl'fzgerald Jan. 20, 1942- J. H. FITZGERALD CONCRETE MIXER Filed April 2, 1941 3 Sheets-Sheet 3 ually shifted from an open to a closed position.

Patented Jan. 20, 1942 vireo starts" OFFICE CONCRETE MHXER James H. Fitzgerald, Westfield, N. J.

Application April 2, 1941, Serial No. 386,543

9 Claims. (01.

Also in such types of concrete mixers the, discharge door is manually operated and necessi-zy tates the operator of the mixer to mount the truck frame or chassis to gain access to the usual hand wheel for the operation of the discharge door.

In the type of concrete mixer in use at the pres-:- o ent time the revolving drum is charged with the dry aggregate and a water tank carried by the truck is usually provided with two comp-artments, one compartment containing the greater quantity of water for controlled delivery to the; aggregate in the drum for mixing therewith, while the other smaller compartment contains rinse water controllably fed to the drum for cleaning the latter after discharge of the mixed his garments.

It is therefore the primary object of the pres-, 40 ent invention to improve the construction and operation of both the charging and discharging 1 doors for the drum of the concrete mixer and to I improve the water charging facilities for the two compartments of the water tank that deliverswater to the drum.

A further and important object of the invention is to provide pneumatic, hydraulic or vacuum devices for the operation of the charging and discharging doors for the mixer drum with,

said doors operable from remote points, thereby eliminating the necessity of an operator climbing over the frame of the truck carrying the drum to gain access to the doors.

A further and important object of the invender of the ram.

tion is to improve the water charging facilities for the two compartments of the Water tank whereby a single filling opening is provided with branch means for delivering water simultaneously to the mixing and rinse Water compartments of the tank together withatelltale device or indicator to show when the two compartments of the water tank have been charged with the proper amount of water so that a signal may be given by the operator filling the tank to shut off the water supply. I

With the above and other objects in view, the

' invention consists in general of certain novel details of construction and combination of parts hereinafter more fully described, illustrated in the accompanying drawings and specifically claimed.

In the accompanying drawings:

Fig. 1 is a vertical longitudinal sectional view of a concrete mixer constructed in accordance with the present invention, a part of the frame structure of the carrying truck for the concrete mixer drum being fragmentarily illustrated, showing the ram operated charging and discharging doors and the improved water tank filling means.

Fig. 2 is a fragmentary top 'plan View, partly broken away and shown in section, to illustrate the clevis bars carried by the ram for the operation of the discharge door.

Fig. 3 is an enlarged fragmentary vertical longitudinal sectional view showing the conduit means for the pneumatic, hydraulic or vacuum power devices extending through the mixer drum for communication with the ram-operated charging door,

Fig. 4 is an enlarged fragmentary longitudinal sectional view showing the ram-operated charging door in its closed position and the motive supply means communicating with the cylin- Fig. 5 is a cross sectional View taken on line 5-5 of Fig. 4, showing the'elevated plate carrying the ram providing, a chamber for the reception of the charging door when in open poparts of the motor truck are illustrated as providing supporting elements for certain parts of the present invention, the truck parts illustrated include base rails 10 from the rear ends ofwhich rise perpendicular channel irons II. The mixer drum comprises a cylindrical wall I2 having front and rear tapering end wall portions I3 and I4, respectively, the tapering end wall portion I4 being of frusto-conical form and providing a discharge opening I5 adapted to be closed by the door designated in general by the reference character I6. The cylindrical wall l2 of the drum has a charging door opening II adapted to be closed by the charging door designated in general by the reference character l8. In mixer drums of this general character there is usually provided at the forward end thereof, such as in continuation of the forward tapering end wall portion I3, a straight end wall I9 extending beyond the forward portion of the tapering end wall I3 and fashioned as a gear wheel 20 adapted for engagement with the usual drive pinion of the truck mechanism.

As shown in Fig. 1 a part of the frame structure 2| encloses the end wall I9 and gear 20 of the mixer drum and within said frame structure 2| there is provided a standard or base support'22 having a shaft bearing 23 at its upper end for the support of a shaft that extends through the drum and upon which the latter is rotatably mounted.

A hollow shaft 24 extends axially of the mixer drum I2, the forward end 24" of the shaft being annularly enlarged and having a support in the bearing 25 carried axially of the forward end wall IQ of the drum, the rear end 24 of the tubular shaft 24 terminating adjacent the rear end of the cylindrical wall l2 of the mixer drum. A pair of water bells 25 and 21 are carried by and are in communication with the tubular shaft 24, the water bell 21 being secured to the rear terminal end 24 of the shaft 24, the water bell 26 being mounted on the shaft between the ends thereof. The support for the rear end of the shaft 24 within the drum I2 comprises a tubular shaft having end leg portions 28 and 29 connected at their outer ends to the cylindrical wall I2 of the mixer drum, the inner ends of the leg portions 28 and 29 terminating in proximity of thelongitudinal axis of the mixer drum and carrying a forwardly directed fitting 30 secured to the outer bell 21 and a rearwardly directed nipple fitting 3| for purposes presently to appear.

The mounting for the discharge door I6 comprises a shaft 32 arranged coaxially with the tubular shaft 24, the forward end of the shaft 32 being rigidly secured to the nipple fitting 3| as shown in Fig. 3 and being of a length to extend outwardly through the discharge door opening I5, said shaft 32 having an axial bore 33 extending therethrough, with the bore communicating with the legs 28 and 29 of the transversely extending tubular shaft that supports the rear end of the shaft 24. A bearing collar 34 rotatable with and slidable upon the shaft 32 carries a peripheral flange 35 to which the central portion of the web 36 of the discharge door I6 is connected, the discharge door I6 comprising said web 35 that carries at its peripheral edge a V-shaped flange including flange walls 31 and 33, the flange wall 31 being located for engagement with the outer face of the tapering rear wall portion I4 of the mixer drum outwardly of the discharge door opening l5 to form a closure for said opening. To facilitate sliding movement of the bearing collar 34 upon the shaft .32, an elongated sleeve 39 surrounding the shaft 32 has one .end secured as at .40 to the forward end of the bearing collar 34, while the other end of said sleeve is provided with a cap .4! in proximity of the nipple fitting 3| and so disposed when the discharge door I6 is in its closed position.

The discharge door I6 with its bearing collar 34 is slidable longitudinally of the shaft 32 when moving from open to closed positions relative to the discharge opening I5 in the mixer drum and said discharge door may be pneumatically or hydraulically operated, or operated in the presence of vacuum, and as illustrated and for purposes of clarity only, the operating means for the discharge door will be referred to as pneumatically operating means. As shown in Figures 1 to 3, an angular and transversely extending channel iron 42 is connected at its ends to the upright channel iron II and occupies a position slightly below the alined shafts 24 and 32, the channel iron 42 being positioned rearwardly of the discharge door and its opening and carrying intermediate the ends thereof a platform 43 for the support of a ram. A pair of angle brackets comprising upright legs 44 with base flanges 45 are respectively secured in spaced relation to the front and rear edges of the platform 43, the vertical legs 44 .of the brackets providing a sup.- port for the cylinder 46 of the ram. The cylinder 4.6 ,of the ram houses a reciprocating piston 41 that carries a piston rod 48 extending through the :forward end of the cylinder 46, the forward end of the piston rod 48 having a forked pivotal connection 49 with a pair of divergent clevis arms 50. As shown more clearly in Fig. 3, that portion of the bearing collar 34 projecting rearwardly of the web 36 of the discharge door I6 is provided with an annular groove 5| in which groove is freely mounted a collar or ring 52 carrying diametrically opposite radially projecting pins 53 received in pivot openings formed in the forward ends of the clevis arms 50.

The supply of air to the cylinder 46 of the ram for the operation of the piston 41 includes a pipe line 54 extending from a controlled source of energy, the pipe line 54 as illustrated in Figs. 1 to 3 being in communication with a transverse- 1y extending pipe line having leg portions 55 and 56, the leg portion 56 of the pipe line being in communication with the outer end of the ram cylinder 46, while the leg '55 of the pipe line is in communication with the side of the cylinder :46 adjacent its forward end as illustrated.

It will be understood that the mixer drum I2 is rotatably supported upon a carrying truck and that the shafts 24 and 32, the tubular shaft support comprising legs '28 and 29 and the discharge door I6, rotate as a unit while the ram device and its associated clevis remain stationary by reason of the ring connection 52 with the collar 34 carried by the discharge door.

The charging door opening I I and its associated charging door I8 are set into the depressed wall portion 12 of the cylindrical drum I2 and a ram'for the operation of the charging door I8 is alsoxsupported on said depressed wallportion. The charging door and the operating means therefor comprise a charging door 5;! supported at its side edges and slidable upon a pair of rails 58 carried by the wall portion I2 at opposite sides of the opening la], the guide rails '58 extending a considerable distance rearwardly of said charging opening I! for the support .of the door 51 when in its open position. Alsoa pair of cross rails 5.9 extend transversely of the charging opening I! at the frontand rear edges theredoor 51 comprises a ram similar in construction and operation to the ram for the operation of the discharging door, the ram for operating the charging door 51 comprising a cylinder 60 supported at its ends in the vertical legs 6| and 62 of angle brackets, the base flanges 63 of the angle brackets being mounted upon and secured to the front and rear ends respectively of a raised plate 64 having depending side flanges 65- anchored to the depressed wall portion I2 of the mixer drum as clearly shown in Figs. 4 and 5, this arrangement of the raised plate 64 providing a chamber 66 for the reception of the charging door 51 when in its retracted open position. From an inspection of Fig. 6 it will be noted that a pair of longitudinally extending guide flanges 61 are carried by the wall portion I2 at opposite sides of the door opening I! that overlie opposite side edges of the charging door 51 for holding the same tightly engaged with the track rails 58 when the charging door is in its closed position.

The cylinder 58 of the ram for operating the charging d-oor houses a reciprocating piston 68 and said piston carries a forwardly extending piston rod 69 that has a pivotal connection 10 at its forward end with a pair of upstanding lugs 7| that are secured at their lower ends as at 12 to the forward end of the charging door 51. It will be understood from an inspection of Fig. 4 that when the piston 68 moves rearwardly in the cylinder 60 of the ram, the door 51 will be retracted into its open position relative to the charging opening I! and be received in the chamber 66 afforded by the raised plate 64.

It is also understood that the ram for the operation of the charging door |8 may be pneumatically or hydraulically operated or operated in the presence of a vacuum and pneumatic means for the operation of the ram only will be described. As shown in Fig. 3 the rearwardly projecting end of the pipe 32 that supports the discharge door I6 has an axial bore 33 therein covered by an end cap 13 with a gasket 14 interposed between the end of the shaft 32 and said cap 13, there being axial openings in the cap and gasket for the passage of a stationary nipple 15 that is adapted to be placed in communication with a source of motive fluid. The stationary nipple l terminates slightly beyond the gasket 14 and is in communication with a relatively small fluid pipe line 16 extending through the bore 33 of the shaft 32 and being rotatable with said shaft. The forward end of the pipe line 16 is bent at right angles and extends through the supporting leg 28 of the strut for the support of the rear end of the tubular shaft 24, said pipe line 16 passing outwardly of the mixer drum through the depressed wall portion l2 as shown in Figs. 4 and 5 for communication with a transversely extending pipe line having pipe line leg portions 1'! and 18, the leg portion 11 communicating with the cylinder 60 of the ram through the side wall thereof adjacent the forward end, while the leg portion 18 communicates with the rear end of the cylinder 60. The placement of the pipe line 16 in the axial bore of the shaft 32 and in the tubular supporting leg 28 for the shaft 24 protects the pipe line from the excessive weight and impact of the aggregate material within the mixer drum.

The water tank for the concrete mixer is illustrated in Fig. 1 and is in communication with the tubular shaft 24 for supplying mixing water to the water bells 26 and 21 within the mixer drum. The water tank 19 is supported on the frame structure 2| forwardly of the mixer drum and at an elevation above the tubularpipe 24 for the gravitational flow of water to said pipe, but it is to be understood that a pump may be interposed in the water supply line if desired. A partition is arranged in the tank 19 to provide a relatively large compartment 8| for mix water to be delivered to the drum l2 and a relatively small compartment 82 for rinse water for delivery to the mixer drum for cleaning the latter. It has heretofore been the practice to provide separate water charging openings for the mixing and rinse water compartments of a water tank,

but to overcome the serious objections to'suchpractice, the presentinvention provides a single water charging opening for the tank with means for directingthe water into both compartments. A single water filling neck 83 rises from the tank 19 above the mixing water compartment 8| to be closed by a cap 84, the lower end of the water filling neck 83 within the mixing water compartment 8| having branch outlets 85 and 86,,the outlet 85 discharging into the mixing water compartment 8| ,while outlet 86 extends through the partition 88 and is provided at its discharge end with a gravitationally closing valve 81, Water delivered to the tank 19 through the sin. gle neck opening 83 flows into both compartments 8| and 82, the latter compartment when filled having the supply thereto cut off by the gravitationally closing valve 81 and when the mixing water compartment 8| has been filled to the desired level, the telltale device or float indicator 88 will rise above the tank 19 so that the supply of Water to the tank may be out off. For the controlled delivery of the water from the compartments 8| and 82 of the tank 19 tothe tubular shaft 24 and water bells 26 and 21, there is provided a pipe connection 89 between the compartment 8| of the tank and the T-fitting 90 with a control valve 9| in the pipe connection 89, while a pipe connection 92 with a control valve 93 therein is in communicationwith the other end of the T-fitting 90. A flexible tubular connection 94 is formed between the T-fitting 96 and the tubular shaft 24.

As hereinbefore stated, it has been necessary with the present type of concrete mixers, for operators thereof to climb over the machine for access to and operation of the charging and discharging doors of the mixer drum, but with the present invention the operator may remotely control the discharging and charging door either pneumatically, hydraulically, or in the presence of vacuum. It is the usual practice to rotate the .drum |-2 during the delivery of the concrete we during normal operation rotates in a clockwise direction and the internal vanes 85 upon theinner wall of the drum in addition to agitating the aggregate tend to move the same away from the discharge door opening I5. When the material is to be discharged and the discharging door l6 opened'by the ram, the drum is rotated in a counter-clockwise direction and the internal vanes or ribs 95 effect the discharge of the mixed concrete to the discharging opening l5.

From the above detail description of the invention, it is believed that the construction and operation thereof will at once be apparent, and

while there is herein. shown and described the preferredembodiment thereof, it is to be understood that minor changes may be made in the details of construction, such. as will fall within the scope of the invention as claimed.

Iclaim: f

1. In a truck mixer for concrete and the like a rotatable mixer drum, said drumhavingjfilling and discharging openings therein, a slidably mounted closure door for each openin a ram for operating each door and a platemounted in spaced relation to the wall of the drum for the support of the ram for operating the filling open.- ing closuredoor and laterally of said filling opening, said ram having a piston rod attached atiits forward end to theforward end of the filling opening closure door with the latter when in open position slidable into the space between the wall of the .drum and the plate supporting'the ram. a

2. In a truck mixer for concrete and the like, a rotatable mixer drum, said drum having filling and. discharging openings therein, a slidably mounted closure door for each opening, a ram for operating each door, a plate mounted in spaced relation to the wall of the drum for the support of the'ram for operating the filling opening closure door and laterally of-said filling opening, said ram having a piston rod attached at its forward end to the forward end of the filling opening closure door with the latter when in open position slidable intothe space between the wall of the drum and the plate supporting the ram and the wall of the drum supporting the filling opening closure door and operating ram therefor being countersunk to substantially maintain the overall radial dimensions of the drum.

3. In a truck mixer for concrete and the like, a rota-table mixer drum, said drum having filling and discharging openings therein, a closure door for the discharge opening, a slidably mounted closure door for the filling opening, a ram for operating the filling opening closure door, a hollow shaft in said drum for the support of water bells, said shaft being supported at its forward end in the front end of the drum, a tubular strut extending transversely of the drum and providing a support for the rear end of the hollow shaft and an operating fluid supply conduit for the ram extending through said tubular strut.

' 4. In a truck mixer for concrete and the like, a rotatable mixer drum, said drum having filling and discharging openings therein, a closure door for the discharge opening, a slidably mounted closure door for the filling opening, a rainfor operating the filling opening closure door, a hollow shaft in said drum for the support of Water bells, said shaft being supported at its forward end in the front end ofthe drum, a tubular strut extending transversely of the drum and providing a support for the rear end of the hollow shaft, an operating fluid supply conduit for the ram extending through said tubular strut, an

axial shaft at the rear end of the drum upon which the discharge door is mounted and being supported at its forward end on the tubular strut and saidfluid supply conduit extending through said axial shaft and exteriorly of the drum for communication with a source of energy.

5 In a-truck mixer for concrete and the like, a rotatable mixer drum, said drum having filling and discharge openings therein, a slidably mounted closure door for each opening, an axial shaft in the drum projecting through the discharge opening for the slidable support of the discharge door, a'ram for operating each door and the shaft for the support of the discharge closure door forming a part of a conduit for the supply of operating fluid to the ram for operating the filling opening closure door.

6. In a truck mixer for concrete and the like, a rotatable mixer drum, said drum having a discharge opening therein, a slidably mounted closure door for said opening, an axial shaft in the drum projecting through said opening for the slidable support of the door, a ram supporting frame rearwardly of thedrum, and a ram on the supporting frame cperatively attached to said door.

'7. In a truck mixer for concrete and the like, a rotatable mixer drum, said drum having a discharge opening therein, a slidably mounted closure door for said opening, an axial shaft in the drum projecting through said opening for the slidable support of the door, a ram supporting frame rearwardly of the drum, and a ram on the supporting frame axially alined with said shaft and operatively attached to said door.

8. In a truck mixer for concrete and the like, a rotatable mixer drum, said drum having filling and discharge openings therein, a slidably mounted closure door for each opening, an axial shaft in the drum projecting through the discharge opening for the slidable support of the discharge door, a ram for operating each door and the shaft for the support of the discharge closure door forming a part of a conduit for the supply of operating fluid to the ram for operating the filling opening closure door and a frame structure rearwardly of the mixer drum for the support of the closure door operating ram with the ram axially alined with said shaft.

9. In a truck mixer for concrete and the like, a rotatable mixer drum, said drum having filling and discharge openings therein, a slidably mounted closuredoor for each opening, an axial shaft in the drum Projecting through the discharge opening for the slidable support of the discharge door, a ram for operating each door and the shaft for the support of the discharge closure door forming a part of a conduit for the supply of operating fluid to the ram for operating the filling opening closure door, and said drum having a countersunk portion in the side wall thereof for the mounting of the ram and closure door for the filling opening.

' JAMES H. FITZGERALD.

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