# Патент USA US3304598

код для вставкиFeb- 21, 1967 D A. HAUSMANN IMPACT-ACTUATEf) SPRING SYSTEM FOR PRODUCING 3,304,591 VIBRATIONS IN A ROTATING FORM Filed June 8, 1964 2 Sheets-Sheet l INVENTOR, 054 5A’? )4. MrwA/mm/ BY Afr-news)? , Feb. 21, 1967‘ o. A. HAUSMANN Filed June‘ 8, IMPACT-ACTUATED SPRING SYS VIBRATI ONS IN A HOT 1964 ‘ FOR PRODUCING NG FORM ' 3,304,591 _ ‘ 2 Sheets-Sheet 2 INVENTOR. ?lziiifi, Mai/$14M” BY Irma/n1; United States Patent C) if ' 3,3M,5l591 Patented Feb. 21, 1967 1 2 3.304591 the form and transmitting them to the form with a minimum loss of power and maximum amplitude. It is a further object of this invention to provide a llMPACT-ACTUATED SPRING SYSTEM FOR PRO DUCING VIBRATIONS IN A RQTATING FORM Delbert A. Hausmann, Glendale, €alif., assignor to Ameri can Pipe and Construction Co., Monterey Park, Calif” vibrational system for rotating devices in which the motive power is supplied by the rotation of the device itself. It is another object of the invention to provide a vibra a corporation of California Filed June 8, 1964, Ser. No. 373,454 6 Claims. (Cl. 25-30) tional system for rotating devices in which the vibration is generated by a spring system impelled in synchronism This invention relates to a method of producing with its natural frequency into continuous half-wave vibrations in a rotating form or analogous device, and 10 vibrations, by motive means spacedly mounted on the more particularly to a system in which vibration is im device itself. parted to the form by the impact of a spring-impelled It is a still further object of the invention to provide member, and the spring-impelled member in turn is set a vibrational system of the type described in which the in oscillation by impact thereagainst of protuberances vibrational force is adjustable. judiciously spaced around the periphery of the rotating 15 It is still another object of the invention to provide a form. Although described herein speci?cally in connec system of the type described which permits the use of tion with a centrifugal casting process for concrete pipes, several independent vibratory units on the same device the method may be applied to the centrifugal casting of without mutual interference. other materials and to other processes requiring simul These and other objects of the invention will become 20 apparent from a perusal of the following speci?cation taneous vibration and rotation. -Up to the present time, vibration of a rotating form taken in connection with the accompanying drawings, in has usually been accomplished with a power-driven high which: frequency vibrator or oscillator mounted either directly FIG. 1 is a side elevation of the device of this inven tion; and on the form, or on an external wheel or shoe in contact with the form. The ?rst method is unsatisfactory be 25 FIG. 2 is a vertical section, partly broken away along cause of di?‘iculties in transmitting power to the rotating line 2—-2 of FIG. 1. ' vibrators and because vibrations are produced only at Basically, the system of this invention consists of pro ?xed locations on the form. The second method is in viding cams around the perimeter of a rotating form or e?icient because the frequency of the powered vibrator similar device. As the form rotates, the cams rhythmi is generally much higher than the natural frequency of the external mounting system, a condition which sup cally propel a stationary impact wheel away from the presses the amplitude of vibration of the contact wheel or shoe. Also, much of the energy supplied to the vibration is lost in viscous and frictional damping in the ming momentum is expended, the spring rebounds the im pact wheel against the form, only to encounter another cam which again propels it away. If the angular velocity vibrator mounting system. form against the bias of a spring. As soon as the cam 35 of the mold and the cam spacing is so related to the The present invention overcomes these di?iculties and natural frequency of the spring system that the rebound ine?iciencies of the prior art by providing a stationary, impact occurs precisely as the impact wheel encounters adjustable-bias vibrating spring system which impacts the leading edge of the next following cam, the system uniformly around the perimeter of the form as it rotates, sustains its vibrations with maximum efficiency and ampli 40 and whose motive power is supplied by the camming tude and hence with a minimum of camming energy. action of cams or protuberances judiciously spaced Referring now to the drawings, the rotating form is around the perimeter of the form to synchronize the shown at 10. It rests on pairs of support wheels 12 and impact repetition rate with the natural frequency of the drive wheels 14, the latter of which are powered by a spring to provide maximum amplitude and power utiliza motor 16. The perimeter of the form 10 carries one or . tion. The system of the invention has been empirically proven to be very effective in consolidating both granular and plastic materials, and it will be readily understood by those skilled in the art that it has the following ad vantages over the prior art: (1) vibrations are trans 45 more rings 18, 20 which in turn are provided with cams or protuberances 22. Bearing against the surface of rings 18, 20 and against the cams 22 are impact wheels 24. The impact wheels 24 are biased against the rings 18, 20 by 50 springs 26 contained within the telescoping cylinder mem bers 28, 30. Wedges 32 operated by hydraulic controls mitted uniformly around the circumference of the form; (2) any desired impact frequency can be producedby proper selection of spring, wheel assembly weight, and 34 permit the impact Wheels to be moved into and out of contact with the form 10. The static biasing force with which the wheels 24 are biased against the surface of the cam spacing; (3) no separate power source is required rings 18, 20 can be adjusted by means of the set screw 36. for the impact system; (4) all energy required to com 55 It will be noted that the cams 22 on ring 18 are dis pensate for damping losses is supplied by the rotating placed by one-half their perimetric interval from those on form through impact of the cams; (5) the system of ring 20. The purpose of this arrangement is to prevent this invention transmits a higher percentage of the vibra mutual interference between the vibrations set up by the tion force to the rotating mass than the systems of the two vibrating systems——i.e., the impact on ring 18 occurs prior art, with a consequent minimal loss of energy 60 while the wheel 24 associated with ring 20 is out of con through the mounting means to the support frame; and tact with the ring 20 at the end of its compressive stroke (6) the impact strength is adjustable. In addition, when (dot-dash line position of wheel 24 on FIG. 2), and vice two impact units are operated against the same rotating versa. form, interference between vibrations from the two Operation sources can be eliminated by locating the cams on one 65 band one-half space out of phase with the cams on the When the spring-mounted impact wheel 24 is brought second band. This phase-shift principle can be extended into contact with the form 10, it is impacted in sequence to any number of impact units. by each of the cams 22 on the ring 18 or 20. After each It is therefore the object of this invention to provide impact, the wheel 24 describes one-half cycle of simple a vibrational system for rotating devices capable of_dis 70 harmonic motion as it is driven downward against the tributing vibrations uniformly around the perimeter of spring 26 and rebounded by it against the ring 18 or 20. 3,304,591 4 6 6 The period of time required for each impact cycle is a function only of the natural frequency of the spring sys w 3 — TREE: tem and can thus be calculated from the known mass and spring de?ection constant of the vibrating system. For maximum effectiveness, the cams 22 can be spaced so that the frequency with which they pass the impact 3 wheel 24 is exactly equal to twice the natural frequency of the spring system. When this condition is satis?ed the impact wheel develops its maximum amplitude and de scribes a continuous series of half-sine waves with im ( 12) Since the total number of carns is 27R Substitution in Equation 12 gives wn "-217 10 pact occurring between each Wave. Assuming a rotating form 10 having rings 18, 20 of radius R which in turn carry a series of equally spaced (13) Example Form diameter=23", R=1l.5 in. peripheral earns 22 so arranged that each strikes in se Spring factor, K: 1000 lb./in. quence and with equal force a spring-supported wheel 24 15 Vibrating weight (including 1/2 spring wt.), w=50 lb. Form operating speed to be approximately 135 rpm. of eifective mass m. Assume the impact delivered by each cam 22 drives the wheel 24 downward at an initial From Equation 2 velocity V0. Neglecting viscous damping and other losses, the change in kinetic and potential energy of m is equal to work done by the spring in opposing motion. Thus V: velocity after displacement x, kzspring factor in pounds per inch deflection, and x0: static spring de?ection. Since kxo=mg _135(21r) =14.l 60 w_ 25 From Equation 13 the number of cams required is w,,_ (2) 30 . _ _. Provide 12 cams at _,2lr_ s— 12 -6.02 H tem is I? 88.0 TI’—2E——2(14-1 —12.0 and the natural frequency of the undamped spring sys wax/E radians per second radians/sec. Most effective operating speed is (3) Equation 1 reduces to (4) It will be seen that the present invention provides an At maximum displacement x1, V=0, and from Equation 4 V2____Vo2__wn2x2 extremely simple, efficient and adjustable method of vi brating rotating forms. Obviously, the concept of the Vozwnxl (5) invention can be carried out in many different ways, of which the embodiment shown and described herein is so that Equation 4 can be rewritten V=wn\/:c12—x2 merely illustrative. Therefore, the invention is not to be (6) deemed limited by the foregoing description, but only It is evident from Equations 5 and 6 that, from the time 45 by the scope of the following claims. What I claim and desire to secure by Letters Patent of impact until the wheel 24 again contacts the ring 18 or 20, the sprung mass oscillates in simple harmonic mo is: 1. In combination with a rotating form, a vibrating tion for which the displacement at time t is x=x1'sin wnt system comprising: stationary resilient means; impact (7) means carried by said resilient means and resiliently biased thereby into engagement with said rotating form; and the velocity is da; V=E=wnxycos wnt and means on said rotating form for engaging said im pact means to compress said resilient means in synchro (8) At maximum displacement nism with twice the natural frequency of said resilient 55 means. 2. In combination with a rotating form, a vibrating cos wnt1=0 system comprising: stationary resilient means; impact and means carried by said resilient means and resiliently biased thereby into engagement with said rotating form; w t —I n 1"‘2 60 During the rebound portion of the cycle all energy gained by the spring is expended in restoring the original poten tial and kinetic energy of mass m. Equations 7 and 8 apply, and the period for a complete cycle is thus twice the time given by Equation 9, or and equally spaced protuberances around the perimeter of said rotating form arranged to engage said impact means to compress said resilient means in synchronism with twice the natural frequency of said resilient means. 3. In combination with a rotating form arranged to rotate at a predetermined angular velocity, a vibrating system comprising: stationary resilient means, impact means carried by said resilient means and resiliently biased thereby into engagement with said rotating form; and equally spaced protuberances around the perimeter of To insure that all actuating cams 22 strike in sequence, the center-to-center cam spacing s should be equal to the 70 said rotating form arranged to engage said impact means peripheral distance traveled during one impact cycle, i.e., s=RwT (11) where w is the angular velocity in radians per second, or .from Equation 10 to compress said resilient means at twice the natural frequency of said resilient means when said form is ro tating at said predetermined angular velocity. 4. In combination with a rotating form, a vibrating 75 system comprising: stationary resilient means adjacent 3,304,591 5 6 each end of said rotating form; impact means carried by thereby into engagement with said rotating form adjacent each of said resilient means and biased thereby into en the ends thereof; equally spaced cam means around the gagement with said rotating form; and equally spaced periphery of said rotating form adjacent each end there camming means around the perimeter of said form ad jacent each end thereof arranged to periodically engage of arranged to engage said impact wheels to compress said resilient means at twice the natural frequency of said resilient means when said form is rotating at said said impact means to compress said resilient means upon rotation of said form; the leading edges of said camrning predetermined angular velocity; and means for vary means adjacent one end of said form being perimetrically ing the force biasing said impact wheel against said form; spaced from the leading edges of said camming means the leading edges of said cam means adjacent one end adjacent the other end of said form by one-half the peri 10 of said mold being perimetrically spaced from the lead metric distance between adjacent camming means. ing edges of said cam means adjacent the other end of 5. In combination with a rotating form arranged to ro said mold by one-half their perimetric interval. tate at a predetermined angular velocity, a vibrating system comprising: stationary resilient means; impact wheel means carried by said resilient means and resilient ly biased thereby into engagement with said rotating References Cited by the Examiner UNITED STATES PATENTS 15 form; equally spaced cam means around the periphery of said rotating form arranged to engage said impact 763,329 1,199,997 wheel to compress said resilient means at twice the natural frequency of said resilient means when said form 20 1,992,739 2/ 1935 Carrington __________ __ 25-30 2,703,916 3/1955 Butler ______________ _. 25——3O is rotating at said predetermined angular velocity; and means for varying the force biasing said impact wheel against said form. 6. In combination with a rotating form arranged to rotate at a predetermined angular velocity, a vibrating 4,843/ 26 227,190 6/1904 10/1916 Rowntree ___________ __ 25-41 Lienesch ___________ .__ 25--3O FOREIGN PATENTS 11/ 1927 Australia. 3/ 1960 Australia. system comprising: stationary resilient means adja 25 J. SPENCER OVERHOLSER, Primary Examiner. G. A. KAP, R. D. BALDWIN, Assistant Examiners. cent each end of said form; impact wheel means carried by each of said resilient means and resiliently biased

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