Патент USA US2122249код для вставки
June 28, 1938. 2,122,249 J. P. FABER SEAL FOR'ROTARY CONCRETE MIXING DRUMS Filed Dec. 24,, 1935 7:, INVENTOR. BY m ‘ ATTORNEY. 2,122,249 Patented June 28, 1938 UHTED STATES PATET QFFIQE 2,122,249 SEAL FOR ROTARY CONCRETE» MIXING DRUMS , John P. Faber, Dunellen, N. J., assignor to Ban some Concrete Machinery Company, Plain ?eld, N. .l., a corporation of New Jersey Application December 24, 1935, Serial No. 55,979 5 Claims. (Cl. 285—1) present improvements employ, in the illustrated The improvements relate to means for pro— viding a substantially liquid-tight seal or packing between a rotating member and a stationary part, and more particularly to a seal of this char acter between the fixed feed chute or hopper and the feed opening _of a rotating concrete mixing drum. They may however be used in connection with the discharge chute and opening if desired. and for any other purpose to which they are 31:0 adaptable. _ In modern concrete mixing it has been found advantageous to seal the feed or charging open ing of the drum to ‘prevent the wet aggregates or “soup” from splashing out as the aggregates are preferred embodiment, an annulus of sheet or thin cast metal secured to the external periphery of the cylindrical discharge end of the feed chute and projecting therefrom in vertical plane to form a flange throughout the circumference of the chute, and the feed opening is provided with a pair of spaced rings of rubber or other suitable compressible and resilient material extending around its edge and projecting inwardly there 10 from, and receiving snugly between them the annulus. As the charge opening and the said flange of the chute are both annular and are raised by the mixing buckets or blades, dropped concentric and the compressible rings are formed on aligned radii the seal is maintained at all times 15 from the upper part of the drum and more or and. is not affected by the rotation of the drum, less violently agitated and moved about in differ ent directions, to produce a thorough and uni form commingling of all the aggregates. But as the drum rotates quite rapidly and the feed chute which rotation is on a horizontal axis running through the centers on which the annular ?ange, the said rings and the edges of the opening are which extends through the mouth or feed open ing of the drum must be mounted in ?xed posi tion to receive and deliver into the drum the un mixed aggregates, the problem of providing an - effective and durable liquid-tight seal between the two has been a serious one, on account of the relatively large diameter of the chute and the opening, the vibration caused by the rotation of the drum with its heavy load and the dumping of the unmixed aggregates into the chute in large batches, and the extremely gritty character of the small aggregates in the liquid portion of the mix ture which are principally hard sand and minute fragments of rock mixed‘ with cement and water. Various attempts have been made to provide a seal of this character which will be effective at all times and under‘all conditions and will be suf ?ciently durable in use to keep the cost for up keep and replacement within reasonable limits, drawn. The pair of compressible rings is secured 20 to the head of the drum around the opening by being clamped against the inner and outer faces of said head immediately adjacent to and sur rounding the said opening, one ring being on the outer face and the other on the inner face there of, and the rings extend beyond the edge of the opening and toward the chute a short distance to provide contact surfaces between them and the annular ?ange sufficient to form an eiiective seal. This extension of the ?exible rings also provides 30 fora certain degree of flexibility to compensate for vibration and the slight lateral movements of the drum in rotating or due to other causes. The flexible rings are clamped to the head of the drum at the edge of the opening by means of ?at annu 35 lar metal plates one on the outer side of the outer ring and the other on the inner side of the inner ring with bolts at intervals passing through the said ring and plates and through holes in the drum head, one or both of the said plates prefer lem has heretofore been devised. Seals which ably extending to the edges of their respective are initially fairly satisfactory have been made at rings or in proximity thereto to reinforce and a cost comparable with the cost of the present protect them and preserve their shape. The in seal, but as their life is very short, the cost as . terposition of the rings however between the high as sixty dollars for a one yard machine and plates at their points of securement gives the the labor and delay involved in replacement a latter a slight degree of flexibility in addition to the'flexibility of the relatively thin metal of which serious item they have not been found satisfac tory. Nor have such devices been so designed as they are made. The objects and advantages of the improve to provide a tight seal under all conditions of use, as where the mixing drum is carrying an overload ments will be apparent from the foregoing, and 50 of the usual wet mixture bringing the level of from the following description and accompany ing drawing which describe and illustrate an such mixture when at rest up to or above the but so far as I am aware no solution of this prob lower edge of the opening. To overcome the di?lculties above indicated 55 and provide an e?ective and durable seal, the exemplary embodiment thereof. In the said drawing, Fig. l is a vertical medial cross section taken longitudinally through the 55 2 2,122,249 head of a concrete mixing drum and feed chute embodying the improvements; Fig. 2 is an end elevation thereof, with part of the chute broken away; and Fig. 3 is an enlarged detail in section similar to that of Fig. l of certain parts. In the said drawing l is the feed chute, 2 the head of the drum, 3 the annular sealing ?ange on the chute, 1%, 4a, the pair of rubber sealing rings, 5 the outside and 6 the inside metal c1amp-_ ing ring, 7 one of the securing bolts for the rings and their reinforcing plates and 8 a union for a water pipe leading to the chute through the mouth 9, through which water is discharged 15 into the drum for the batches of solid aggregates. The bolts 1 are located at short intervals around the edge of the feed opening, and have their heads on the inner side of the plate 6 which should be made in two semi-circular sec 20 tions for insertion and removal through the opening—extend through the plate 5, compress ible ring 4, drum head 2, compressible ring 4a and plate 5 and beyond the last named plate, the outer end of each bolt being threaded to re ceive a nut la, and a spring nut lock ‘lb being located between the said nut and the plate 5 on the bolt. The plates 5 and E extend approximate ly to the inner edges of the compressible rings, but I prefer to have the rings extend slightly 59 beyond the plates so that there will be less wear on their extreme inner edges, and small gritty particles of aggregates will be swept away from the ?ange 3 thereby and permitted to fall when the portion of the rings on which they have lodged reach a position above the middle of the opening. The space between the compressible rings is slightly greater than the thickness of the ?ange 3, this being provided for by having the ?ange slightly less in thickness than the head of 40 the drum 2. Thus the head of the drum in prac tice is about 1/;th inch in‘thickness while the ?ange is lisths. The plates 5 and 6 are of about the same gauge as the ?ange, and are of spring metal, so that they have a slight degree of ?ex ibility. This ?exibility, however, is increased, and the entire extending portion of the compress ible packing rings and their plates is permitted when the portions of the rings which lap the head are compressed, the extending portions will be brought closer together, so that a satisfactory seal can be maintained in spite of considerable Wear, and the life of the packing thus prolonged. While the construction and arrangement here in described and shown is the best mode in which I have contemplated applying the principle of the invention, it will be apparent that it may be modified in various ways and applied to or com 10 bined with other devices, without departing from that principle. What I claim is: l. A seal for the head of a rotatable drum for mixing concrete having a central opening 15 therein and a non-rotating chute extending therethrough, comprising an annular ?ange on the chute, a plurality of packing rings of elas tic material mounted on said head and extending beyond the edges of said opening spaced apart 20 and providing a space between them for the re ception of said ?ange corresponding substan tially to the thickness of said ?ange and metal lic reenforcing members for said rings mounted in close contact therewith, means for constantly 25 pressing said members against said rings, one of said members being on the 'outer side of each ring and also extending therewith beyond the edges of the opening, said members overlapping said ?ange. 30 2. A seal for the head of a rotatable drum for mixing concrete having a central opening there in and a non-rotating chute extending there through, comprising an annular ?ange on said chute, a plurality of packing rings of elastic 35 material mounted on said head and extending beyond the same over said opening spaced apart and providing a space between them correspond ing substantially to the thickness of said ?ange and metallic reenforcing members for said rings 40 mounted in close contact therewith, means for constantly pressing said members against said rings beyond the edges of the opening, and means for securing said rings adjustably and remov ably to said head at least one of said members 45 overlapping said ?ange. 3. A seal for the head of a rotatable drum for to move or ?ex to the desired extent by the fact that the rings of compressible material are be tween the plates 5 and 6 and the drum head 2. Adjustment for the wear of the rings 5 and 6 due to friction between them and the ?ange 3 mixing concrete having a central opening there in and a non-rotating chute extending there through, comprising an annular ?ange on the 50 chute, a plurality of packing rings of elastic is provided by the means of attaching them to the drum head, and especially the spring nut lock and extending beyond the edges of said opening spaced apart and providing a space between them for the reception of and corresponding substan .55 tially to the thickness of said ?ange and a metal lic clamping and reenforcing member for said rings mounted therewith and extending there .55 lb. ‘When a new packing or seal is applied to the head of the drum and secured by the screw bolts '1, the pressure of the plates 5 and 6 will cause the compressible material of the rings 4 and (la to be compressed to some extent between .60 the plates and the head 2. This permits the said plates to approach each other slightly and nar row the space between the extending portions of the packing rings, which is not compressed, and thus establish a snug relation between the rings 65 and the ?ange 3. The exact desired tightness of the seal can thus be attained by regulating the pressure of the nuts ‘la. At the same time a fur ther slight yielding of the plates is provided for by the spring nut locks ‘lb. These nut locks per mit the user to tighten up the packing when it is worn down by friction between it and the ?ange 3 by turning up the nuts, as Well as providing a certain yielding of the entire packing to com pensate for vibration and slight movement of the drum and feed chute, it being apparent that material mounted one on each side of said head with over said ?ange, means for removably se curing said rings and reinforcing member to said 60 head, and a spring device for pressing said rings associated with said securing means and having locking engagement therewith. 4. A seal for the sheet metal head of a rotat able drum for mixing concrete, having a central 65 opening therein and a non-rotating chute ex tending through said opening, comprising an annular ?ange on the chute, a plurality of pack ing rings of elastic material mounted one on each side of the head adjacent to and extending be 70 yond the edges of said opening, so that said rings are spaced apart by said head and provide an annular space between them in which the outer part of said ?ange is received, means for com pressing said rings against said head and thereby 75 3 2,122,249 causing their said extending portions to approach each other and reduce the space in which the ?ange is received, to take up wear or make a closer seal between said parts, said means in UK cluding relatively rigid members secured to said head and extending inwardly beyond the edges of said opening over a major portion of and in contact with said rings, a portion of said rings being free to move laterally to compensate for 10 lateral movement of the ?ange without discon tending beyond‘the same with said packing ring, a chute extending through said opening but spaced from the edges thereof, an annular ?ange on said chute in plane with the head, said pack ing ring and reinforcing plate overlapping said ?ange, and means for securing said‘ ring and plate to the head, causing pressure upon said ring beyond the edges of the opening to press it against said ?ange, maintain a seal between said ring and ?ange and take up wear, comprising a 10 necting them. bolt extending through the ring, head and plate, '5. In a device of the character described, a sheet metal head having a central opening, an between the head and the plate constantly press elastic packing ring secured near the edges of the opening and extending well beyond the same and clear of said head, a reinforcing plate also secured near the edges of the opening and ex a head on said bolt and a spring on said bolt ing the extending portion of said plate against said ring. JOHN P. FABER.