US2369608A - Apparatus for forming hollow bodies - Google Patents

Description

Feb. 13, 1945. s v gsc 2,369,608

APPARATUS FOR FORMING HOLLOW BODIES Filed Jan. 16, 1940 2 Sheets-Sheet l 1322:: Fw wlsl V 21 4 Inventor Feb. 13, 1945. P. SALVANESCHI 2,369,608

APPARATUS FOR FORMING HOLLOW BODIES Filed Jan. 16, 1940 2 Sheets-Sheet 2 [72 2/672 for P/NO \S/4LV/4/VESCH/ Patented Feb. 13, 1945 APPARATUS FOR FORMING HOLLOW BODIES Pino Salvaneschi, Broni, Italy; vested in the Alien Property Custodian Application January 16, 1940, Serial No. 314,030 In Germany February 18, 1939 13 Claims.

Processes for manufacturing pipes with or without sockets, of cement paste which may contain fibrous matter, are well known. In many such processes a wrapping drum or cylinder is provided on which the pipe is formed in successive compressed layers. The speed of the wrapping drum in many of the above-mentioned processes depends on the speed of a felt band, of a ribbon, or of a roller.

Therefore, when a pipe having asocket is being wrapped, the angular speeds of the contacting rollers, or the linear speed of the felt band or ribbon, cannot be constant for the whole of the pipe length, since these speeds must be proportional to the various diameters of the pipe. In other words, the socket portion usually is of a greater diameter than the remaining portion of the pipe and, therefore, the speed of the feltband or ribbon must be varied accordingly.

Consequently, whatever mechanical device is adopted, the portion of the pipe disposed between the small and large diameters is always a region of least structural resistance and of least impermeability, and the tools required are always complex and expensive. The same may be said concerning the compression, simultaneous or subsequent to the shaping of the pipe. There is an additional disadvantage during the compression on account of the'pipe pressure requiring heavy tools to avoid fienural stresses. These high pressures, however, are sometimes partially reduced by mechanical means.

The weight of the parts in motion and the inherent friction cause, in general, the whole compression system to be insensitive in its operation.

Other processes for manufacturing pipes from fibrous pastes are also known, whereby a rotatable supporting cylinder having holes therein is employed. The cylinder and holes are covered by a filtering fabric and the fabric is smeared or covered with a given thickness of paste, the inside of said cylinder being subjected to a reduced pressure or suction for draining the water from the applied paste in a manner practiced in the operation of any drum-filter. (See, for instance. Die Asbest-Zement Schlefer Fabrication-a practical handbook-by K. A. Weniger, M. Krajn editors, Berlin, 1926,- from page 160 to page 164). In these processes, however, the condensing and compression of the material are limited.

The present invention is characterized by the feature that the kneaded paste, whatever beits nature. is deposited upon a vibrating or oscillating table. This table is preferably inclined with movement at a certain distance toward and away from a revolving cylinder, which cylinder is formed from porous or permeable material. A reduced pressure or suction may be maintained within the porous or permeable cylinder, and the paste is thrown against the cylinder and deposited on it by the vibrating or oscillating table. The angular speed of the cylinder upon which the paste is applied, is independent of the speed of the other members of the apparatus, regardless of the diameter or diameters of the pipe.

The other distinguishing features of the present invention will be disclosed in the specification with the help of the attached drawings which are intended to give purely an example of an embodiment which is likely to vary in practice in its details, without thereby exceeding the limits of the present invention.

In said drawings:

Figure 1 is a longitudinal section of the apparatus, taken along the line 11-! in Figure 2;

Figure 2 is a sectional plan view taken along line 2-2 in Figure l, but omitting portions of the feed hopper;

Figure 3 is an enlarged transverse sectional view, with the central portion thereof broken away, said view being taken along lines 33 in Figures 1 and 2;

Figure 4 is a sectional view illustrating a modified form of feed hopper;

Figure 5 is a sectional view illustrating a modified form of table construction in association with the revolving cylinder upon which the pipe is formed.

Referring more particularly to the drawings, the numeral I designates a hollow perforated cylinder or drum over which paste 2a is strewn or deposited to form a pipe 2, said cylinder having trunnions 3 and 3' which are removably and rotatably supported in U-shaped notches Na in side frames 2!. An inclined vibrating or oscillating table 4 is disposed between side frames 2|, the lower end of said table being supported by eccentrics l0 and its upper end being pivotally connected to the upper ends of suitable links [5 as at; points 5. The lower ends of links 6 are mounted around rotating eccentrics 8 which are fixedly secured upon a shaft 1. Likewise, the eccentrics l0 are fixedly secured'upon a shaft H.

The eccentrics H) on shaft I I may be turned gradually during operation for adjusting or varying the degree of rapid oscillation of the upper respect t a horizontal plane and mounted for 5 end of the table, said rapid oscillation being sisame time a slower or gradual motion is imparted to the lower portion of the table in the direction C-D and DC when the shaft II and eccentrics ID are turned. There is also a longitw dinal motion imparted by the eccentrics to the table.

As stated above, the lower end of the table 4 is supported by eccentrics III, and, therefore, upon gradually revolving the eccentric in a clockwise direction from the position shown through an angle of 180, the inclined top surface of the table will be moved away'from the cylinder or drum I in a direction DC substantially normal to said surface, while at the same time the upper end of the table is vibrating or oscillating rapidly. The table will also be moved longitudinally downwardly in the direction of incline during the first 90 rotation of eccentrics III and longitudinally upwardly in the direction of incline during the succeeding 90 rotation. Therefore, each oscilla-v tion of the table resulting from eccentrics 8 will follow a slightly different path from the path of the preceding oscillation, on account ofthe gradual shifting of the lower pivot point III. Of course, the relative rates of rotation of the respective eccentrics 8 and II) varies the frequency and the paths of oscillation followed by the table. The shaft I at the upper end of the table structure is driven very-rapidly by any suitable conventional means such as disclosed in Figure 2. As an example of the driving means, the upper shaft I has a sprocket 25 fixedly secured thereon upon which a chain 26 is mounted, said chain being also mounted upon a sprocket II of a speed reduction unit 28. The reduction unit is driven by any suitable means such as an electricmotor 30 in a conventional manner.

The lower shaft I I is driven slowly or gradually in a similar manner by sprocket II, chain 32 and sprocket 33. Although, a common driving means is employed for the upper and lower eccentrics 3 and II), a separate driving means may be employed. It is evident-that good results may be obtained if the eccentrics I are manually rotated while the table oscillates or vibrates. In the present showing the two pulleys 21 and 3| are geared so that pulley 21 will be driven very rapidly while pulley 3| is driven very slowly. In other words, the vibratory or oscillating motion is imparted to the upper end of the table 4 through members 5, 6, I, 8, 25 and 26 while the table is moved away from cylinder I by members II), II, 3I, 32 and 33 to provide clearance for the paste 2a which is being deposited on the rotating cylinder I to form pipe 2. Usually, the entire amount of paste is deposited during the first 180 degrees revolution of eccentrics III, and during the second and successive turns of eccentrics III the pipe is compressed and consolidated. Although the entire amount of paste may be deposited upon the rotating cylinder or mandrel I during the first 180 of revolution of eccentric I 0, it should be borne in mind that the mandrel may rotate several revolutions. In other words, when the table is located in its uppermost position as shown in Fig. 1, there is a minimum space between the periphery of the mandrel and the top of the table, and this minimum space is substantially equal to the sheet of pasty substance 2:; which is being applied to the mandrel. After the mandrel has made substantially one revolution, the eccentric III will .have turned downwardly a sufficient amount to plastic material will have formed on top of the first layer. In other words, when the mandrel is rotated a plurality of revolutions during the formation of the pipe, the plastic material will be applied in the form of a spiral winding. At all times, the uppermost limit of the travel of the table approaches the periphery of the cylinder sufficiently to compress the pasty substance which is being applied.

A fly wheel 8 is fixedly secured upon shaft 1 so that a greater momentum will be maintained after the shaft has reached the operating speed. Since the table oscillates at a high rate, the shaft I must rotate correspondingly fast, and under such conditions it is sometimes necessary to counter-balance the fiy-wheel as at 9a to balance the centrifugal weight of the eccentrics 8 about rotating shaft I.

The proximate faces of side frames 2| have sides I9 and 20 extending inwardly therefrom into close proximity to opposite edges of table 4, to thereby prevent the paste from falling from the sides of the table when the table is oscillating. The top surfaces of the side members I9 and 20 are shaped in such a way as to closely approach, without touching, the large and small peripheries at each end of the cylinder I, the intermediate portion of said cylinder disposed between said sides" being adapted to receive the paste 2a from the table 4. (See Figure 3) The removable cylinder I to which paste 2a is applied may be driven either in a continuous or a non-continuous way. A conventional continuous driving means is shown, comprising a sprocket 35 fixedly mounted onthe end of trunnion 3', a sprocket chain 36, a second sprocket 31, a gear reduction unit 33 and a motor 33. It is evident that the rate of rotation of cylinder I will be much slower in relation to the rate of rotation of shaft I which operates to oscillate or vibrate the table so that the paste can be properly deposited on the cylinder in successive layers. v

The charging hopper is designated by reference character I2 wherein is deposited the whole amount of paste 2a for obtaining a pipe of a given size, said hopper having an opening 12a in the lower end thereof which is substantially closed by table 4 when the link 6 is at the uppermost position of its stroke.-

Upon rapidly oscillating the upper end of inclined table 4, the paste 2a intermittently falls out of the hopper onto the uppermost portion of the table and is caused'to flow downwardly, with the assistance of gravity toward revolving cylinder I. As the paste approaches the cylinder it is applied thereto by the above-described oscillations to thereby form a pipe 2. The lower end of the table is gradually moved away from the cylinder due to the rotation of shaft I I during the application of the paste 2a and the formation of the pipe 2.

The drum or cylinder I is porous or permeable only in the part which receives the paste, said pores in the cylinder being indicated by Ia (Figure 3). Cylinder I is also provided with holes I3 and with a head I6, havin'gproiections II, integral therewith, said holes I3 establishing communication between the interior of cylinder I and an annular space 40 in sleeve I8. The sleeve I8 siidably fits over the cylinder I in the manner shown in Figure 3. and when so positioned the annular space 40 establishes communication between holes I3 and passageways I4 and IS, the passageway I! being disposed substantially in alinement with the axis of rotation of cylinder I.

' Attention is called to the perforations no in inserted into passageway I5 and is connected to the cylinder by any suitable means such asa sealed ball bearing 43. A suction pump 44 is connected to the other end of the conduit, and a valve 45 is employed in the conduit to regulate the amount of suction produced.

The excess water in the paste 2a filters through the pores Ia into the cylinder I and is discharged therefrom through openings I3, 4|], I4, I5 and into suction conduit 42, as a result of the suction means.

The operation is as follows:

The required paste id for a given pipe 2 is placed in hopper I2, after having set the vibrating or oscillating table at its top-dead-center so as to close or reduce the opening I2a. The eccentric I0 is also set in the position shown so as to reduce the space between cylinder I and table 4 to the desired minimum. The upper portion of the table is then set in motion due to the rapid rotation of drive shaft I, and the paste flows with the aid of gravity from opening I2a towards the cylinder I. At the proper moment the cylinder I is rotated and also the vacuum or suction apparatus is placed in operation. A slower rate of rotation is simultaneously imparted to the lower shaft II and eccentrics III to gradually move the table downwardly from the cylinder to give space for the pipe thickness, during which downward move ment the contents of the hopper are deposited upon cylinder I.

If the vibro-compression, produced by the vibrating or .oscillating table 4 upon the pipe during its formation, is not considered sumcient, the operation of cylinder I and table 4 is continued to thus consolidate the pipe.

As soon as the pipe is considered finished, after the above-stated operations, it is possible to go on with the vibro-compressing, i. e. by continuing the oscillation of the table, and if desired the suction within cylinder I may be reduced so as to insure that the inside surface of the finished pipe may separate'from the outside surface of the cylinder.

When the formation of the pipe is completed,

the cylinder I is disconnected from conduit 42 and from driving chain 36, after which the cylinder and finished pipe is removed from notches 2 la. The pipe is then slipped from the cylinder by pushing the sleeve I8 toward trunnion 3', or by holding the sleeve and then extracting the cylinder. Also the pipe may be removed by placing both the pipe and cylinder in upright position and dropping the cylinder and sleeve endwise on the floor so as to leave the pipe vertical.

In the practical embodiment of the process, the oscillations may be very different in nature, frequency, direction, and amplitude. In the apparatus shown in Figures 1 and 2, as an example, the oscillations are in the direction A-B, B-A, and are gradually damped toward the lower end of the table. These oscillations may be replaced by others, whatever be the'kinematic or dynamic 1 law they are obeying, and whatever be the ratio between the oscillations at a certain point and those at any other point of the vibrating table. As above stated, these oscillations may be varied by rotation of the eccentric I0 about its axis I I.

Hopper I2, shown in Figure 1, may be replaced, if desired, by a dumping hopper I2 such as shown in Figure 4, the hopper being adapted to rotate about point 120.

It is not necessary to uniformly deposit the paste on the vibrating table for the entire length of the pipe generatrix. The vibration of the table provides for the application of the paste where required, that is, the spreading of the paste longitudinally of the cylinder.

The manufacture of the pipe may be obtained even in a single revolution of the drum, in which case the initial distance or the air-gap between the top of the table and the cylinder, when the table is in hold line position, as shown in Figure 5, establishes the thickness of the non-compressed pipe (Figure 5). In such case the table 4 may be suitably concaved as at 4a so that a portion of the concavity will approximately conform to the body of the cylinder. Also in this embodiment, (Figure 5) since only one layer of paste is applied to form a pipe the eccentric III at the lower end of .the table, should not turn because the space between cylinders I and 8 the top of the table will remain constant. The pressing and finishing of the formed pipe by means of vibro-compression may be obtained, whatever be the way the paste is applied over the drum.

Having now particularly described the nature of my invention and its manner of operation, I claim:

l. A machine for manufacturing tubes, pipes or similar hollow bodies from pasty substances comprising in combination a rotatably mounted permeable cylinder, said cylinder adapted to have suction means connected thereto for exhausting air from the inside of said cylinder; an inclined paste-applying member located near the surface of said cylinder, means located near the upper end of said pasteapplying member for depositing a pasty substance upon said member, said member being pivotally mounted for oscillation toward and away from said cylinder to thereby apply and compress said deposited pasty substance to said cylinder as said cylinder rotates; and means for gradually moving said table pivot and associated oscillating table away from said cylinder while said paste is applied to thereby provide space for the applied paste on said cylinder.

2. A machine for manufacturing tubes, pipes or similar hollow bodies from pasty substances comprising in combination a rotatably mounted permeable cylinder, an inclined paste-applying mem-- ber located near the surface of said cylinder, means located near the upper end of said pasteapplying member for depositing a pasty substance upon said member, said member being pivotally mounted for oscillationtoward and away from said cylinder to thereby apply and compress said deposited pasty substance to said cylinder as said cylinder rotates; and means for gradually moving said table pivot and associated oscillating table away from said cylinder while said paste is applied to thereby provide space for the applied paste on said cylinder.

3. A machine for manufacturing tubes, pipes or similar hollow .bodies from pasty substances comprising in combination a rotatably mounted permeable cylinder adapted to have suction means connected thereto for exhausting air from the inside of said cylinder, an inclined paste-applying table having the top surface thereof located adjacent the lower surface of said cylinder; paste delivery means throttled face and located at a point above said adjacent table and cylinder surfaces; and means for vibrating said table toward (1 away from said delivery means and toward and away from said cylinder to respectively facilitate the gravity flow of the pasty substance from the delivery means and to compress the delivered paste upon said rotating cylinder.

4. A machine as defined in claim 3 wherein means are provided for gradually moving the top surface of said vibra table away from said cylinder surface while said paste is applied to thereby correspondingly increase the thickness of the pipe being formed.

5. A machine as defined in claim 3 wherein means are providedfor gradually increasing the distance between the top surface of said vibrating table and the lower surface of said cylinder while said paste is applied to thereby correspondingly increase the thickness of the pipe being formed.

6. A machine as defined in claim 3 wherein said means for delivering the supply of paste to the table comprises a hopper for holding said paste, said hopper having an outlet at its lower end disposed djacent the top surface ofthe table.

7. A machine as defined in claim 2 wherein oscillating means are provided for said table comprising an eccentrically mounted memberflxed upon a rotating shaft and a link pivotally connecting said eccentrically mounted member with said table.

8. A machine as defined in claim 2 wherein oscillating means are provided for said table comprising an eccentrieally mounted member fixed upon a shaft and a link pivotally connectin said eccentrically mounted member with the table, and wherein said means for moving said table pivot comprises a second eccentric rotatably journaled in the table.

9. A machine for manufacturing tubes, pipes or similar hollow bodies from pasty substances comprising in combination a rotatably mounted cylinder, an inclined paste-applying member having the top surface thereof located adjacent the vlower surface of said cylinder, the upper portion of said top surface being adapted to have a mass of pasty substances deposited thereon,

and means for vibrating said inclined member toward and away from said cylinder, whereby the gravity flow of the deposited pas y substances along said top surface and the compression of said substance upon the cylinderrwill be facilitated.

10. A machine forrmanufacturing tubes, pipes or similar hollow bodies from pasty substances comprising in combination a rotatably mounted cylinder, an inclined paste applving member having the top surface thereof located adjacent the lower surface of said cylinder, the upper portion of said top surface being adapted to have a mass of pasty substances deposited thereon,

lrlysaidtablesurpasty substance to said means forvlbratins said inclined member toward and away from said cylinder, whereby the gravity flow of the deposited pasty substances along said top surface and the compression of. said substance upon the cylinder will be facilitated, and means for moving the top'surface of said inclined vibrating member away from the lower surface of said cylinder while the paste is being applied to the cylinder to thereby correspondingly increase the thickness of the pipe being formed.

11. A machine for manufacturing tubes, pipes or similar hollow bodies from pasty substances comprisin in combination a rotatably mounted cylinder, an inclined paste-applying member having the top surface thereof located adjacent the lower surface of said cylinder, the upper portion of said top surface being adapted to have a mass of pasty substances deposited thereon, means for vibrating said inclined member toward and away from said cylinder, whereby the gravity flow of the deposited pasty'substances along said top surface and the compression of said substance upon the cylinder will be facilitated, and means for increasing the distance between the top surface of said vibrating member and the lower surface of said cylinder while the paste is being applied to the cylinder to thereby correspondingly increase the thickness of the pipe being formed.

12. A machine for manufacturing tubes, pipes or similar hollow bodies from pasty substances comprising in combination a rotatably mounted permeable cylinder, said cylinder adapted to have suction means connected thereto for exhausting air from the inside of said cylinder; an

inclined paste-applying member located near the surface of said cylinder whereby pasty substances deposited upon the upper portion of said member will tend to move toward said cylinder, said member being pivotally mounted for oscillation toward and away from said cylinder to thereby apply said deposited pasty substances to said cylinder as said cylinder rotates; and means for gradually moving said table pivot and associated oscillating table away from said cylinder while said paste is applied, to thereby provide space for the applied paste on said cylinder.

13. A machine for manufacturing tubes, pipes or similar hollow bodies from pasty substances comprising in combination a rotatably mounted permeable cylinder, an inclined paste-applying member located near the surface of said cylinder whereby pasty substances deposited upon the upper portion of said member willtend to move toward said cylinder, said member being pivotally mounted for oscillation toward and. away from said cylinder to thereby apply said deposited cylinder as said cylinder rotates; and means for gradually moving said table pivot and associated oscillating table away from said cylinder while said paste is applied to thereby provide space for the applied paste on said cylinder.

PINO SALVANESCHI.

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