US3704862A - Vibrator - Google Patents

Vibrator Download PDF

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Publication number
US3704862A
US3704862A US92121A US3704862DA US3704862A US 3704862 A US3704862 A US 3704862A US 92121 A US92121 A US 92121A US 3704862D A US3704862D A US 3704862DA US 3704862 A US3704862 A US 3704862A
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United States
Prior art keywords
vibrator
support
rod
piston
vibrating
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Expired - Lifetime
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US92121A
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English (en)
Inventor
Virginio Sironi
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VIBRATECHNIQUES
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VIBRATECHNIQUES
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B1/00—Producing shaped prefabricated articles from the material
    • B28B1/08—Producing shaped prefabricated articles from the material by vibrating or jolting
    • B28B1/087—Producing shaped prefabricated articles from the material by vibrating or jolting by means acting on the mould ; Fixation thereof to the mould
    • B28B1/0873—Producing shaped prefabricated articles from the material by vibrating or jolting by means acting on the mould ; Fixation thereof to the mould the mould being placed on vibrating or jolting supports, e.g. moulding tables

Definitions

  • a vibrator particularly for the manufacture of moulded concrete products, comprises a support for a mass to be vibrated and means for vibrating the support, said means including a reciprocable member having an elastic portion for increasing the acceleration of the support during vibration thereof when it is near its extreme positions of vibration;
  • This invention relates to a vibrator, for example for the manufacture of moulded concrete products.
  • a support table is vibrated sinusoidally with time. This has the consequence that the acceleration of said support is likewise a sinusoidal function of time. This gives rise to the disadvantage that, since the frequency of operation of the installation is low, acceleration is always rather poor and is even equal to zero during the changing of the direction of movement of the piston. This makes it impossible to obtain high efficiency in operation, particularly in a concrete vibration installation in which the movable support is moved vertically and in which it is necessary for the acceleration to have a value very close to that of gravity in order to enable the mass to be vibrated to behave like a fluid and for its components to be distributed homogeneously.
  • the present invention may provide a vibrator which is less subject to the above disadvantages.
  • a vibrator comprises a support for a mass to be vibrated and means for vibrating the support; said means including a reciprocable member having an elastic portion for increasing the acceleration of the support during vibration thereof when it is near its extreme positions of vibration.
  • the reciprocable member is a connecting rod, the elasticportion being a portion of the rod, the length of which can vary in dependence upon compressive and tractive forces to which it is subjected in operation.
  • the connecting rod may be arranged to drive a piston, the piston communicating with a chamber adapted to contain a liquid, said chamber being bounded by a movable member connected to the support so'that in operation vibrations of the piston are transmitted through the liquid to the support.
  • the movable member may be a flexible diaphragm.
  • the elastic portion may comprise two relatively movable parts, one attached to one end of theconnecting rod the other attached to the other end of the connecting rod, and at least one elastic element acting upon the two parts to bias them towards a predetermined relative position which is intermediate extreme relative positions between which the parts may relatively move.
  • the one relatively movable part may be a hollow cylinder, the other relative movable part being a piston disposed therein, the elastic element being a spring within the cylinder.
  • the support may be a table.
  • FIG. 1 illustrates diagrammatically a concrete vibrator installation according to the invention
  • FIG. 2 is an axial section of part of the installation of FIG. 1;
  • FIG. 3 is a diagram showing the variation of the position of the piston plotted against time in a prior art vibrator.
  • FIG. 4 shows a corresponding diagram obtained in a vibrator according to the invention.
  • FIG. 1 The installation illustrated in FIG. 1 comprises a vertical cylindrical container 1 disposed on a rigid foundation 2 and containing an internal coaxial cylinder 3 the bottom of which is constituted by the bottom 4 of the container.
  • An annular chamber capable of being filled with a liquid 5, for example oil, is thus available around the cylinder 3.
  • This chamber is closed at the top by a movable closure wall constituted by a flexible diaphragm 6.
  • the periphery of this diaphragm is fastened sealingly in a circular groove 7 formed in the edge of the container 1, and its central portion is fastened, likewise sealingly, in a circular groove formed in a thickened portion 8 of the cylinder 3.
  • the annular portion of said diaphragm 6 is consequently movable in a vertical direction under the action of the pressure of the liquid 5.
  • a guide piston 9 fastened at the top to a ring 10 by a clamp nut 11 is adapted to slide in the cylinder 3.
  • said ring 10 being solid with a movable support table 12 intended to support a mass of concrete to be vibrated.
  • the bottom surface of the ring 10' rests on the annular portion of the flexible diaphragm 6, so that the movements of said diaphragm are transmitted to the movable support 12, which is thus ultimately carried by the liquid 5.
  • the container 1 is in communication with a lateral cylinder 13 the axis of which is horizontal and in which a piston 14 is adapted to move.
  • Said piston is driven by a connecting rod represented generally by 15, its big end 16 being connected to a rotary driving element constituted by a pulley 1'7.
  • Said pulley is driven rotationally by a motor 18 and a belt 19.
  • the big end of the connecting rod is adapted to slide radially in a slot 20 in the pulley, thus enabling it to be fixed at different distances from the center, so as to adjust the stroke of the piston 14 in known manner.
  • the arm of the connecting rod 15 is composed of two rigid portions 21 and 22 connected by an elastic portion 23, which is illustrated in greater detail in FIG. 2.
  • This elastic portion comprises a piston 24 connected to the connecting rod big end by the rigid portion 22, said piston being adapted to slide in a cylinder 25.
  • This cylinder is closed at both ends by screw stoppers 26a and 26b.
  • the stopper 26a is fixed to the rigid portion 21, thus enabling the cylinder 25 to be joined to the portion 21 connected to the connecting rod little end.
  • Each of the faces of the piston 24 is provided with a groove 27 receiving the end of a coil spring 28a and 28b bearing respectively against the stoppers 26a and 26b.
  • the piston 24 and cylinder 25 can move relative to each other in both axial directions against the action of the springs 28a, 28b.
  • the springs apply opposite forces to the sliding part 24 and when the elastic portion is not subjected to any longitudinal stress these opposite forces tend to hold the piston 24 and cylinder 25 in an intermediate relative position as shown in FIG. 2.
  • the force applied by the springs 28a and 28b can be adjusted by screwing in or out the stoppers 26a and 26b, which thus serve as adjustment means in addition to their function as abutments.
  • the operation of the vibrator is as follows.
  • the driving element 17 is driven in the direction shown by the arrow in a uniform rotary movement by the motor 18 and the belt 19. It follows that the component of the displacement of the big end 16 of the connecting rod in a horizontal plane varies in accordance with a sinusoidal function of time. This has the consequence that if the arm of the connecting rod 15 were entirely rigid thedisplacement of the piston 14 in the cylinder 13 would also vary in accordance with a sinusoidal function of time, as illustrated in FIG. 3, which would entail the disadvantages described above.
  • the elastic portion 23 of variable length stores energy in the middle of the forward and return strokes and gives up this energy at the end of the strokes.
  • This has the consequence that for a given speed of rotation of the driving element the acceleration of the piston 14 is reduced towards the middle of each of its strokes and increased at the end of the stroke.
  • the movement of the piston 14 in the cylinder 13 complies with the function illustrated in FIG. 4, which is a corrected sinusoid, the maxima being sharper and the change of direction at A and B being effected practically without passing through a zero slope.
  • the movable support table 12 is displaced vertically' in accordance with the same function, the liquid 5 being substantially incompressible.
  • the elastic portion 23 increases the acceleration of the support table 12 near its extreme positions of vibration, compared to the acceleration that the support table would have if the elastic portion 23 were not provided.
  • the frequency of the cyclic vibrations to which the support table is subjected can easily be regulated by modifying the speed of the motor 18. It is thus possible for the frequency of the reciprocating movement of the piston to be judiciously selected from the range of low inaudible frequencies, in such a manner that the acceleration of the table 12 will always be close to the optimum value, while remaining compatible with the composition of the material to be vibrated.
  • the amplitude of the vibrations can be adjusted by modifying the radial position of the connecting rod big end 16, thereby determining the stroke of the piston 14 and consequently the amount of fluid moving into and out of the chamber in each cycle, thereby determining the vertical stroke of the support table.
  • a vibrator comprising:
  • said means for vibrating said support including reciprocal member means operatively interconnected to said support for vibrating same in response to reciprocation of said member means;
  • said reciprocal member means including elastically deformable means for increasing the acceleration of the support during the vibration thereof when said reciprocal member means is near its extreme position of motion.
  • said reciprocal member means comprises rod means having a length which is variable during operation of the vibrator, said elastically deformable means being a portion of said rod means with the length of said elastically deformable means varying in dependence on the compressive and tractive forces applied thereto during operation of the vibrator.
  • a vibrator as claimed in claim 2 comprising a chamber adapted to contain a liquid, a piston bounding the chamber, the rod means being arranged to drive the piston, a movable member also bounding the chamber and being connected to the support whereby vibrations of the piston are transmitted through the liquid to the support.
  • a vibrator according to claim 2 further including a rotatable drive crank, and said rod means comprising an elongated multipart connecting rod having one end thereof pivotally connected to said crank, the other end of said connecting rod being constrained for linear reciprocating movement.
  • a vibrator comprising a support for a mass to be vibrated,- and means for vibrating the support, said means for vibrating the support including reciprocal member means operatively interconnected to said support for vibrating same in response to reciprocation of said member means, said reciprocal member means including means responsive to the compressive and tractive forces imposed on said member means during operation of said vibrator for causing the length of said reciprocal member means to vary during the cyclic operation thereof.
  • said reciprocal member means includes first and second portions operatively interconnected for permitting a predetermined amount of relative linear movement therebetween for permitting the length of said member means to vary during the cyclic movement of said member means.

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Ceramic Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Apparatuses For Generation Of Mechanical Vibrations (AREA)
  • Devices For Post-Treatments, Processing, Supply, Discharge, And Other Processes (AREA)
  • Injection Moulding Of Plastics Or The Like (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)
US92121A 1969-11-21 1970-11-23 Vibrator Expired - Lifetime US3704862A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR6940115A FR2067918A5 (enrdf_load_stackoverflow) 1969-11-21 1969-11-21

Publications (1)

Publication Number Publication Date
US3704862A true US3704862A (en) 1972-12-05

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ID=9043421

Family Applications (1)

Application Number Title Priority Date Filing Date
US92121A Expired - Lifetime US3704862A (en) 1969-11-21 1970-11-23 Vibrator

Country Status (8)

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US (1) US3704862A (enrdf_load_stackoverflow)
JP (1) JPS4946371B1 (enrdf_load_stackoverflow)
CH (1) CH525720A (enrdf_load_stackoverflow)
DE (1) DE2057131A1 (enrdf_load_stackoverflow)
ES (1) ES385767A1 (enrdf_load_stackoverflow)
FR (1) FR2067918A5 (enrdf_load_stackoverflow)
GB (1) GB1295116A (enrdf_load_stackoverflow)
NL (1) NL7017010A (enrdf_load_stackoverflow)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2161580B (en) * 1984-07-07 1987-08-12 Peter Robert Davis Variable length connecting rod

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1017685A (en) * 1909-09-29 1912-02-20 Edgar H Mumford Jolt-ramming apparatus.
US1279368A (en) * 1916-10-18 1918-09-17 American Radiator Co Controlling device for mold-jarring machines.
US3151958A (en) * 1957-08-26 1964-10-06 Albert G Bodine Pressurized degasification of crude oil by sonic wave action
US3532325A (en) * 1968-07-23 1970-10-06 Jackson Herman Barnett Jr Method and apparatus for generating shock waves

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1017685A (en) * 1909-09-29 1912-02-20 Edgar H Mumford Jolt-ramming apparatus.
US1279368A (en) * 1916-10-18 1918-09-17 American Radiator Co Controlling device for mold-jarring machines.
US3151958A (en) * 1957-08-26 1964-10-06 Albert G Bodine Pressurized degasification of crude oil by sonic wave action
US3532325A (en) * 1968-07-23 1970-10-06 Jackson Herman Barnett Jr Method and apparatus for generating shock waves

Also Published As

Publication number Publication date
JPS4946371B1 (enrdf_load_stackoverflow) 1974-12-10
FR2067918A5 (enrdf_load_stackoverflow) 1971-08-20
ES385767A1 (es) 1973-04-01
CH525720A (fr) 1972-07-31
GB1295116A (enrdf_load_stackoverflow) 1972-11-01
NL7017010A (enrdf_load_stackoverflow) 1971-05-25
DE2057131A1 (de) 1971-05-27

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