US2822598A - Pipe mold vibrator - Google Patents

Description

Feb 11, 1958 c. w. CHANLUND ET AL 2,822,598

PIPE MOLD VIBRATOR Eval.

Filed May 9, 1955 5 Sheets-Sheet l 646.4 W m4n/.4 afm Feb. 11, 1958 c. w. cHANLUND ETAL 2,822,598

PIPE MOLD VIBRATOR Filed May 9, 1955 15 Sheets-Sheet 2 J6 o l 67`V BY 29 .we @MM/L Feb. 1l, 1958 c. w. CHANLUND r-:TAL 2,822,598

PIPE MOLD VIBRATOR Filed May 9, 1955 5 Sheets-Sheet 3 rraeA/fyf.

PIPE MLD VIBRATOR Carl W. Chanlund, Nampa, Idaho, and Stephen R. Hubbard, Compton, Calif., assignors to Cen-Vi-Ro Pipe Corporation, South Gate, Calif., a corporation of Delaware The invention relates to machinery for the fabrication of concrete pipes by use of a hollow cylindrical mold spun at relatively high speeds wherein concrete while still in a plastic state is deposited evenly throughout the interior of a mold and there held in position while being compacted. The invention herein presented is an improvement upon the invention set forth in Patent No. 2,671,260.

To use dry mix of concrete in spinning molds for concrete pipe to replace the employment of wet concrete previously used raises problems not met in other types of concrete work. Because of the fact that concrete pipe sections are relatively thin and because articles such as concrete pipes are made in large sizes and must stand transportation and somewhat rough handling, it is nevertheless a great advantage to increase the strength of such articles by reduction of the water cement ratio. Difficulty in distributing dry concrete mix about the interior of a spinning cylindrical mold is one of the elements needful of consideration. Drawbacks which have been present in spinning mold machines heretofore used such, for example, as the undue wear upon the moving parts and excessive noise in operation, are accentuated to a still greater degree when a dry mix is attempted to be used.

It is therefore among the objects of the invention to provide a new and improved spinning mold pipe machine which incorporates a vibrator lso designed and so located as to permit a desirable mix of dry concrete to be used in spinning molds of the type currently employed.

Another object of the invention is to provide a new and improved concrete pipe fabricating machine which makes use of a spinning mold wherein the mold is adapted to be effectively vibrated during the placement of relatively dry concrete in such fashion that the major portionof the vibrating energy is imparted to the mold without any substantial amount of vibration `b einginduced in the base and support for the mold or in the driving mechanism.

Still another object of the invention is to provide a new and improved vibrating means for spinning concrete pipe machines wherein the vibrating portion of the device is mounted in such fashion that there is a balance resulting under vibration between the mold and the vibrator whereby the maximum beneficial elect may vbe secured from the vibrational operation in response to a moderate expenditure of energy for the production of the vibrational effect.

States Patent() Still another object of the invention is to provide a new l and improved vibrating device Yfor spinning molds which is relatively simple in construction and adapted to be advantageously located with respect to the moldV and the base upon which the mold is mounted and moreover which is of such construction that it can be readily ad` j justed to impart vibration of diiferent character as occa- 2,822,598 Patented Feb. 11,1958

ice

Still further among the objects of the invention is to spinning concrete molds which is adapted to be adjusted for maximum elfectiveness and which includes belttensioning means for the exible belt drive on the vibrator so constructed and operated as to make possible changing the tension of the belt drives without any displacement of fixed location of the pulleys and the shafts upon which the pulleys are mounted.

Still further among the objects of the invention is to provide a new and improved belt tensioning mechanism by means of which an arm, the opposite ends of which serve to locate relative positions of pulleys, can be varied as to its eifective length thereby to change the tension on a belt extending over the pulleys, which extension is also possible of achievement by simple and positive acting means which makes unnecessary any other shift or change in the structure or operative parts of the device.

Also included among the objects of the invention is to provide a machine which employs one or more unique vibrating members which impart a controlled high-frequency vibration to the concrete mold as the mold is spun, the invention being one making possible use of relatively dry concrete in the production of pipes of uniform con- Figure 2 is a longitudinal sectional view taken on the line 2--2 of Figure l.

Figure 3 is a longitudinal sectional View taken on the line 3 3 of Figure 1.

Figure 4 is a cross-sectional view taken on the line 4--4 of` Figure 2.

Figure 5 is a cross-sectional view taken on the line 5--5 of Figure 6.

Figure 6 is a plan view of the end of the vibrator arm which is mounted upon the stationary support, partly broken away, and showing the cushioned connection by means of which the positioning device is fastened to the vibrator arm.

|In the embodiment chosen for the purpose of illustration there is shown in fragmentary .sectional form a concrete pipe mold 9 of a type commonly used in spinning 'mold-S. The mold is of relatively great circumference as compared -with the portions of the device forming the subject matter of the persent invention and is designed to be supported by means of pairs of trunnions at opposite ends of the mold, one pair comprising trunnions 11 and 12, as shown in Figure l, each of which is equipped with an inated rubber tire 13. The trunnions are located on opposite lsides of a center line running along the bottom lof the mold sufficiently far so that they form a broad support, the treads of the tire being ,directly in'contact with an exterior surface 10 o f the mold and being adapted to absorb and cushion movement of the mold up and down as the operation progresses. Details of a typical machine are shown and described in Patent 'Y 4 No.` 2,671,260.

The lmold is adapted vto be supported on a base or Vframe which is suggested schematically as baseportions 14, 15 and 16.

The vibrating device or vibrator assembly maybe described as constituting in general a vibrator arm or vibrator support arm indicated generally by the reference character 17. The arm is secured to a suitable pair of brackets 18 in turn welded upon a supporting'shaft 19 which Imay be considered as mounted upon the base at the portion 16 by some suitable fixture 2t). The pair of brackets 18 support a cylindrical case 21v having a cylindrical bore 22 therethrough in which is located a bearing sleeve 23. On the interior of the bearing sleeve is a cylindrical bearing aperture 24, the axis of which is substantially concentric with the cylindrical case 21. The axis is identified by the reference character 25.

Within the bearing sleeve is an eccentric sleeve 26 having a bore 27 extending therethrough located such that an axis 28 of the bore is eccentric relative to the axis`25. Located as described the eccentric sleeve has a wide portion 29 on one side and a relatively narrower portion 30 on the opposite side.

In the bore 27 is a pivot or support shaft 31 of special construction. The support shaft is keyed non-rotatably to the bearing sleeve by means of a key 32.

The arm 17 heretofore referred to more properly comprises a pair of flat members 33 and 34 which are parallel to each other and which have holes 35 adapted to slide over the circumference of the support shaft 31 at opposite ends. The support shaft is provided with a pair of annular grooves 36 adapted to receive each a retention screw 37 provided with a lock nut 38 bearing upon an annular enlargement 39. In this fashion the vibrator support arm is firmly anchored upon the support shaft in a position permitting the unanchored end of the arm to move up and down pivoting about the axis 25. An adjusting nut 40 is -welded to one end of the support shaft and inasmuch as the support shaft is keyed to the eccentric sleeve 26, rotation of the support shaft by means of the nut 40 is adapted to rotate the eccentric sleeve 26 within the bearings 23.

At the free end of the arm 17 there is provided a substantially rectangular opening -45 which is surrounded by a frame 46 within which the vibrator is carried. The frame, which may be a part of the arm, is lined with layers of vibration-absorbing pads or sheets '47, V48, 49 and 50. As seen in Figure 3 there is a frame 46 on each ,side each provided with the herein described pads or sheets such that there is a balanced support on opposite4 sides of the vibration assembly. Guards 51 and 52 may be employed to properly confine the upper and lower sheets 50 and 48, respectively.

The vibrator mounting may be described as constituting a housing or body 53 having a cup-like pocket 54 therein and on one side of which is an extension 55. The extension 55 is preferably rectangular'in form and possessed of sides adapted to t respectively against the pads or sheets 47, 48, 49 and 50. A flange 56 also rectangular in form is adapted to engage and be supported by the pads or sheets 47, 48, 49 and 50 of the opposite flat member 34. The iiange 56 has an edge 57 adapted to snugly seal the pocket 54 so that the interior may be packed with oil for effective operation. A vibrator shaft 58 is mounted in bearings 59 and 60 located respectively in the body 53 and the flange 56. An eccentric weight 61 is keyed to the vibrator shaft and provides the means by which vibration is created when the shaft is rotated. A stub shaft 62 extends outwardly of the vibrator shaft and has keyed thereon a pulley 63 by means of a key l64. VWhen the vibrator shaft and eccentric weight 61 is rotated, vibrations are transmitted to the body 53 and then carried through a bracket 65 to a roller 66 which may be describedas a vibrating roller. The roller is mounted by means of a bearing 67 on a roller pin 68 secured to the bracket by means of a nut 69.U As will be noted from an inspection of Figure l, the roller is adapted to roll against the circumference 'of the pipe mold when the mold during its rotation is struck by the 7 .vibratineollaz i 'For operating the vibrator there is provided an electric motor 70 mounted by means of adjustable legs 71 to a portion 15 of the base. The base may be slotted following conventional practice to permit the motor to be adjusted up or down to vary lthe tension on belts 72. The belts 72 are reeved aroundan idler pulley 73 which is mounted by means of bearings 74 upon a stub shaft 7S which is part of the structure of the support shaft 31. -It should be noted in particular that the axis of rotation of the stub shaft 75 is coincident with the axis 25 which is the center of the bearing sleeves 23.

yBelts 76 which are also reeved around appropriate grooves in the idler pulley extend around the driven pulley 63 which is keyed to the vibrator shaft.

Occasions may require the free end of the vibrator arm to be moved up or down depending upon the diameter of the mold 9 which chances to be used with the machine. To thus position the end of the vibrator arm and hence the vibrator there is provided a hydraulic ram indicated generally by the reference character 80. The ram comprises a cylinder 81 pivotally secured to a bracket 32 on a portion 14 Vof the base. A uid pressure line 83 supplies duid under pressure to the cylinder. A piston rod 34 extends upwardly from the ram and is pivotally secured by a pin 85 to a torque bushing indicated generally by the reference character 86. The torque bushing is secured to the ilat members 33 and 34 of the arm 17. By injecting pressure into the pressure line 83, the piston rod 84 will be raised thereby to elevate the position of the vibrator roller 66. To lower the roller, the pressure may be reduced. f

The torque bushing herein selectedfor incorporation into'the vibrating device comprises `a pair rof franges 87 secured to the respective flat members 33 and 34. Slots 8S are provided in the llanges so that the attachment of .the flanges may be initial-ly adjusted to a degree limited bythe lengths of the slots when bolts 89 are tightened. A hollow shaft'9il is Welded to the flanges 87 forming the central'portion of the torque bushing. Surrounding the hollow shaft '96 is -a rubber sleeve 91, the sleeve being confined in position by employment of a sleeve or bushing 92. An ear flange 93, arcuate in form, extends `around the bushing and is bolted thereto by means of bolts 94. A key assists in the interconnection of the ear ange with the bushing anchoring them against rotation one With respect to the other. An ear 96 on the ear flange connectsV with a shackle 97 `at the upper end of the piston rod 84 by means of the pin 85.

In operation the pipe mold 9 is loaded on the trunnions 11 and 12 ready for reception of the plastic concrete which will be vibrated during the spinning operation. While the pipe mold is rotated in accordance with conventional practice, the vibrator is adjusted to a point where the circumference of the roller 66 is positioned in hrm contact with the exterior surface of the pipe mold. The positioning is accomplished by means of the hydraulic or pneumatic ram 80 operated by pressure in the pressure line 83. -After the vibrator has been positioned, the motor 70 is started and the belt 72 rotates idler pulley 83, the rotation of which is transferred through belts '76 to the driven pulley 63 on the vibrator shaft. This causes the eccentric Weight 61 to vibrate and vibrations are set up in the body 53 of the vibrator. These vibrations are transferred to the roller 66 'and lthe roller beats upon the circumference of the pipe mold 9 at the rate of vibration established and with vibrations of predetermined amplitude. The major portion of the vibrational energy is transferred to the pipe mold and pneumatic tires 13 preferred therefrom to any portion of the framework.

Moreover, the sheets or pads 47, 48, 49 and 50 prevent the transferof vibrational energy to the vibrator arm 17.V The transfer of vibrational energy is therefore pre- .vented from thevibrator to the base or frame through the vibrator v The torque bushing isfinstrumental in insuring against transmission of vibrational energy to the fluid system. Although the sheets of rubber-like material or pads 47, 48, 49 andSt have a dampening eect upon vibration, nevertheless, the arm 17 will vibrate up and down. Movement of the arm up and down is transferred to the flanges 87 and to' the shaft 90. By being confined between the shaft 90 and the bushing 92 considerable friction exists between the contacting surfaces. Vibration in the shaft 90 Will be dampened by the rubber sleeve 9i before reaching the bushing 92 and hence the connection to the ram and the fluid pressure system.

During the course of very strenuous usage of apparatus of the kind herein described under the conditions imposed upon it by the usual operation, there may be a tendency for the belts 72 and 76 to loosen. To increase the tension on the belts 76, for example, it is necessary only to place a wrench on the nut 40 and by that means rotate the pivot shaft 31 and hence the eccentric sleeve 26. Rotation of the eccentric sleeve causes the wide portion 29 to shift in its `location and when the wide portion is moved toward the left, Ias viewed' in Figures l and 6, the axis 28 will be moved toward the right as the shaft 31 is rotated. This will cause the arm i7 to be moved toward the right, carrying with it the stub shaft 62 of the driven pulley 63, the shift therefore causing the lbelts 76 to become tighter. It should be noted in this connection, moreover, that the axis of the shaft 75 and hence the center of rotation` of the idler pulley 73 is not shifted because it is coincident with the `axis 25 which is the axis of rotation of the circumference of the eccentric sleeve 26. Hence there` will be no alteration of the tension in the belt 72. These belts can be tightened if need be by shifting the position of the motor 70 downwardly as viewed in Figure l'on the portion 15 of the base which is sloped for that purpose.

Important in the construction and arrangement of the vibrator is the selection of cushioning means embodied in the pneumatic tires 13, and sheets or pads, 47, 48, 49 and 50, and the torque bushing. These vibration dampers are selected in accordance with thevibration-inducing eccentric weight 61 and the ability of the power source, namely, the motor 7i), torotate the eccentric weight. The cushion or dampened connectionsreferred to may properly be described as dynamic couplingsV forming a system involving the masses of the various vibrating parts and frictional damping. The amplitude of vibration will depend upon certain constants in the system well known to those skilled in the art, and'by taking those factors into consideration Yin theV structure herein disclosed a desired amplitude of vibration can be achieved which will be selected to produce best results in the placement of concrete in the pipe mold. The roller 66 does not impart any frictional drag ron ythe pipe mold inasmuch as it is free to rotate whenever contact is made during the vibration.

There has laccordingly been described herein a simple vibrator system which is rugged in construction so as to be capable of prolonged used for the fabrication of pipe in production quantities and which in particular, by balancing masses subject to vibrational effect, makes effective use of vibration with a minimum of disadvantages.

While We have herein shown and described our invention in what we have conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of our invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices.

Having described our invention, what we claim as new and desire to secure by Letters Patent is:

l. In a molding machine having a mold for plastic material the combination of a vibrator device for the mold, a base for mounting the mold and the vibrator Sii device,` a'support'arm pivotally secured'fto thefliaseandl extending to aposition adjacent'V theV mold, a positioner` for the arm' comprising mutually extensible elements and' havingone 'element thereof mounted on' the base Yarid the other element thereof'attached to the4arm','a damper intermediate endsofsaid last identified element, a vibrator frame on a free end of said arm, vibration-absorbing means between. the frame 'andthe arm, a vibration generator mounted on the frame, a vibrating element on the frame positioned in vibrating relationshipl with the mold, a source of power on the base and a drive train of vibration dampingV material from said source of power ,tol the vibration generator.

2. In-a molding machine having a rotating moldv for plastic` material the combination of a vibratordevice for the mold, a" base for mounting the mold and the vibrator device', a support arm pivotallyfsecured to the base' and extending beneath the mo1d,7a positioner for thearm comprising a Huid pressure ram including mutuall'yfextensible elements'and having a stationary element thereof mounted onthe base anda movable element'thereof attached to the arm intermediate ends of the arm, aA cushionintermediate ends of said movable elernennav vibrator frame on a free end of said arm, vibration-absorbing means between the frame and the arm, a-'vib'rator shaft rotatably vmounted on the frame and an veccentric weight on said shaft, a vibratingelement on the frame positioned in vibrating relationship with the mold,l a source of power on the base and a multiple vibration damping flexible drive from said source of power to the shaft.

3. In a centrifugal pipe molding machine'comprising a base, a substantially cylindrical mold rotatably mounted on the base and presenting a smooth cylindrical exterior portion, and resilient trunnions resiliently and 'rotatably supporting said mold on the base, the combination of a vibrator device for the mold -comprising an arm pivotally supported on the base and extending to a position-adjacent'the mold and transverse to the axis thereof, said arm comprising spaced parallel parts, a connecting shaft between said arms intermediate outside `and inside ends, an extensible positioner for the arm comprising a stationary element mounted on thebase and a movable element secured to thefarm, a vibration damping bushing surrounding said connecting shaft and ja bushing having an ear ange thereon surrounding'rsaid vibration ldamping bushing, means attaching said ear flange to said movable element, a vibrator frame mounted on the arm, vibrationabsorbingmeans between theframe-and thearm, a vibrator shaft rotatably mounted'on the'frame and an eccentric weight on said shaft, said shaft being positioned with the axis thereof parallel to the axis of the mold, a vibrating roller rotatably mounted on the frame for vibration therewith, said roller being positioned in vibrating and rolling relationship with the cylindrical exterior portion of the mold, power means on the base and a drive from said power means to said shaft.

4. In a centrifugal pipe molding machine comprising a base, a substantially cylindrical mold rotatably mounted in horizontal position on lthe base and presenting a smooth cylindrical exterior portion, a pair of trunnions on opposite sides of each end of said mold and resilient circumferential portions on said trunnions resiliently and rotatably supporting said mold on the base, the combination of a vibrator device for the mold'comprising an arm pivotally supported on the base and extending beneath the mold and transverse to the axis thereof, an extensible I positioner for the arm comprising a fluid pressure ram including a stationanry element and a movable element, said stationary element being pivotally mounted 4on the base and said movable element being pivotally secured to the arm intermediate the fixed and movable ends, a vibrator frame mounted on the free end of the arm, vibration-absorbing means between the frame and the arm, a vibrator shaft rotatably mounted on the frame and an eccentric weight on said shaft, a vibrating roller rotatably mounted on the frame for vibration therewith, said roller being positioned in Vibrating and rolling rela-V tionship with the cylindrical exterior portion of the mold, rotating power means on the base and a multiple exible drive train of vibration damping belting from said power means to said shaft.

5. In a centrifugal pipe molding machine a base, a substantially cylindrical mold rotatably mounted on the base, and resilient rotatable trunnions on the base supporting the mold, the combination of a vibrator device for the mold comprising an arm extending to a position adjacent the mold, a positioner for the arm comprising a portion thereof mounted on the base and another portion secured to the arm and adapted to shift said arm toward and away from the mold, a vibrator frame on the arm, a vibrator shaft mounted on the frame having a driven pulley thereon, a driving pulley mounted on the base with the center of rotation at a fixed position, a exible belt drive between said pulleys and means for adjusting the tension on said drive comprising a casing on the base having a bearing aperture adjacent the driving pulley, said aperture having an axis coincident with the axis of the driving pulley, an eccentric member in said aperture having a bore therethrough with the axis of the bore offset with respect to the axis of said aperture, said arm being rotatably mounted on the eccentric member, said eccentric member having a driving pulley stub shaft thereon concentric with the axis of said aperture, and drive means enabling rotation of said eccentric member whereby to extend said arm and said vibrator shaft and to shift the axis of the driven pulley relative to the driving pulley without shifting the axis of the driving pulley.

6. In a centrifugal pipe molding machine a base, a substantially cylindrical mold rotatably mounted on the base, and resilient rotatable trunnions on the base supporting the mold, the combination of a vibratorV device for the mold comprising an arm'extending to a position adjacent the mold, a positioner for the arm comprising a portion thereof mounted on the base and another portion secured to the arm and adapted to shift said arm toward and away from the mold, a vibrator frame on the arm, a vibrator shaft mounted on the frame having a driven pulley thereon, a driving pulley mounted on the base With the center of rotation at a fixed position, a llexible vibration damping belt drive between said pulleys and means for adjusting the tension on said drive comprising a casing on the base having a bearing yaperture adjacent the idler pulley, said aperture havingV an axis coincident with the axis of the idler pulley, an eccentric member :comprising an eccentric sleeve in said aperture having. a bore therethrough with the 'axis of the bore offset with respect to the axis of said aperture, a pivot shaft having an enlarged portion Within the eccentric sleeve and non-rotatably keyed thereto, said arm being rotatablyr mounted on the eccentric member, said pivot shaft having a driving pulley stub shaft thereon concentric with the axis of said aperture, and means enabling rotation of said eccentric sleeve whereby to extend the arm toward its free end and to shift the axis of the driven pulley relative to the driving pulley.

7. In a centrifugal pipe molding machine a base, a substantially cylindrical mold rotatably mounted on the base in horizontal position, and a pair of resilient rotatable trunnions on the base supporting each end ofthe mold, the combination of -a vibrator device for the mold comprising an arm extending beneath the mold, a positioner for the arm comprising a portion thereof mounted on the base and another portion secured to the arm and adapted to shift said arm toward and away from the mold, a vibrator frame on the free end of said arm having vibration-absorbing means separating said frame from the arm, a vibrator shaft mounted on the frame having a driven pulley thereon, an idler pulley mounted on the base with the center of rotation at a fixed position, a ilexible belt drive between said pulleys and means for adjusting the tension on said drive comprising a casing on the base having a bearing aperture adjacent the idler pulley, said aperture having an axis coincident with the axis of the idler pulley, an eccentric sleeve in said aperture having a bore therethrough with the axis of the bore oset with respect to the axis of said aperture, a pivot shaft having an enlarged portion within the eccentric sleeve and nonrotatably keyed thereto, said arm being rotatably mounted on the enlarged portion exterior of the casing, said pivot shaft having a drive pulley stub shaft thereon concentric with the axis of said aperture, and means enabling rotation of said eccentric sleeve whereby to shift the arm endwise and to shift the location of the axis of the driven pulley to a different distance relative to the idler pulley Without shifting the axis of the idler pulley.

References Cited in the le of this patent UNETED STATES PATENTS 1,580,308 Lawson Apr. 13, 1926 2,671,260 Jessen et al. Mar. 9, 1954 2,691,553 Pettigrew Oct. 12, 1954 2,724,582 Huff Nov. 22, 1955

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