US3635134A

US3635134A - Vibratory rollers

Info

Publication number: US3635134A
Application number: US881671A
Authority: US
Inventors: Hubert E Thomas
Original assignee: HUBERT E THOMAS
Current assignee: HUBERT E THOMAS
Priority date: 1969-12-03
Filing date: 1969-12-03
Publication date: 1972-01-18
Anticipated expiration: 1989-01-18

Abstract

The name and broad description of the invention is ''''FrictionDriven Vibrator.'''' This invention is a new method of providing power to rotate the eccentric weights or shafts of a vibratory roller. The eccentric weights and shafts are known herein as vibrator elements. This new method utilizes the drawbar pull of the towing vehicle to supply power to rotate the vibrator element(s). The new method provides a friction-driven drive train that secures power from the drawbar pull of the towing vehicle and is dependent on the drawbar pull of the towing vehicle, the tendency of the roller drum to rotate as a force is applied radially to the drum through axles on the ends of the drum which are concentric to the drum, the coefficient of friction between the roller drum and the surface being rolled and compacted, and the weight of the towed roller. Rotary motion and power is transferred from the rotating drum through a combination of means to drive the vibrator element(s) in a rotary fashion.

Description

i Unite Potent 1 ,134 Thomas [4 1 Jan. 18, 1972 [54] VIBRATURY ROLLERS Primary ExaminerJacob L. Nackenofif [72] Inventor: E3.0Thomas, Francis Lane, Chester, [57] ABSTRACT The name and broad description of the invention is Friction- [22] filed 1969 Driven Vibrator." This invention is a new method of providing 2 App] 381, 71 power to rotate the eccentric weights or shafts of a vibratory roller. The eccentric weights and shafts are known herein as vibrator elements. This new method utilizes the drawbar pull U-S- of the towing vehicle to upply power to rotate the vibrator Int 19/28 element(s). The new method provides a friction-driven drive [58] Field Of Search ..94/50 train that secures power from the draw'bar pull of the towing vehicle and is dependent on the drawbar pull of the towing [56] References Cited vehicle, the tendency of the roller drum to rotate as a force is applied radially to the drum through axles on the ends of the UNITED STATES PATENTS drum which are concentric to the drum, the coefficient of fric- 3,069,984 12/1962 Kammerlin ..94/s0 between the drum and the Surface being and 3,395,626 8/1968 Garis ..94/so and weigh the and power is transferred from the rotating drum through a FOR G PATENTS OR APPLICATIONS combination of means to drive the vibrator element(s) in a rotary fashion. 973,986 9/1950 France ..94/50 7 Claims, 6 Drawing Figures PATENTEU JAN 1 8 1972 $635,134

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VIIIIRATOIRY ROLLERS BACKGROUND OF THE INVENTION Current State of the Art The type of vibratory roller that the invention improves on is the type in which the vibrator element(s) is journalcd in bearings and rotated by a drive train drivingly connected to an internal combustion engine, hydraulic or electric motor mounted on the frame of the roller. The vibrator element(s) is caused to rotate to generate a centrifugal force that is transmitted to the drum through said bearings. As the force rotates it lifts and lowers the roller drum for every revolution of the element(s), vibrating, shaking, and pounding the surface that the roller drum is being towed on. The location of the vibrator element(s) is generally inside of the drum and the rotating axis is generally concentric to the roller drum. The drum is connected to and supports a frame through shock absorber elements, stub axles, bearing housings, and bearings that allow for rotation of the drum while it is being pulled through said frame and connecting parts by a towing vehicle.

SUMMARY OF THE INVENTION In the natural course of operating a towed-type roller the drum of the roller is forced to rotate as it is pulled or pushed over any surface because of the friction between the surface the drum is pulled or pushed on and the periphery surface of the drum. The vibrating element drive train is motivated by attaching any power transfer device to the drum or related rotat ing part. The reacting drive train and vibrator element(s) are properly sized so that the pulling action of a properly sized towing vehicle is not slowed nor is the drum caused to stop rotating and skid. The design of the roller using this new method is such that the friction force, which depends on coefficient of friction between drum and surface and the weight of the roller, supplies the necessary power as the drum rotates to rotate the vibrator element(s). The vibrator element(s) is sized to give the desired reaction to the drum shell and surface through the centrifugal force generated as it is rotated at a predetermined rotary speed.

DRAWINGS FIG. I is a side elevational view of a towed-type vibrating roller equipped with a friction-driven drive train.

FIG. 2 is a top plan view of the roller showing a preferred embodiment of the friction-driven drive train.

FIG. 3 is a vertical sectional view of the roller taken along the lines 3-3 of FIG. 2 showing details of the beginning and end of the friction-driven drive train, the drum, and the vibrator element.

FIG. 4 is a partial top plan view of an optional embodiment showing a hydraulic power transfer group included in a friction-driven drive train.

FIG. 5 is a partial top plan view of an optional embodiment showing a multiple speed transmission included in a frictiondriven drive train.

FIG. 6 is a partial top plan view of an optional embodiment showing a electric power transfer group included in a frictiondriven drive train.

DETAILED DESCRIPTION FIG. I, 2, and 3 show a roller with a hollow cylindrical drum I3 enclosed by and supporting a frame 112 with towing eye 10. FIG. 3 shows how the frame is supported by its attachment to the drum and the attaching parts that transmit the towing force from the frame to the drum. On the sprocket side or the left-hand side of FIG. 3 the frame I2 and the attached parts are supported from the ground by the drum flange through the hollow cylindrically shaped shock absorber M that is fastened with screw-type fasteners to the drum flange 15 and stub axle I7. The shock absorber is made of molded rubber or similar material bonded to metal plates. The shock absorbers perform various functions. They isolate a large percentage of the drums vibratory motion from the towing frame. They are among the attaching parts that transfer the towing force from the frame to the drum. They support the frame when the roller is being towed as well as when it is standing statically. They react to the torque in the drive train. In the preferred embodiment shown with reference to FIG. 3 the shock absorber M on the sprocket or left-hand side is the initial power transfer device transferring the rotary motion of the drum and passing it on to the stub axle I7 which turns the driving sprocket 119.

The material and size of the shock absorbers are properly picked for vibration-dampening characteristics, torque resistance to the chain and belt tension, and to support the static weight of the frame assembly as well as extra loads that may be applied by unusual ground engagement (rocks, ruts, or hills) or steering loads that may be imposed by the towing vehicle. Supplemental resilient stops that protect the shock absorbers against possible overload areused on some towed-type vibratory rollers and may be used without detriment on rollers equipped with this invention.

It is understood to be obvious that other arrangements can be made as to the shape and type of the shock absorber(s) used and the method of connecting the: drive sprocket or other means to the rotating drum and any interchange or substitution of power transfer devices will not: circumvent this invention.

Continuing with the detailed description; the stub axle 17 is journaled in bearings 58 and 60 and supports a proportionate amount of the frame and drive train through bearing housing 18 which is bolted to the frame side member 63.

In FIG. 3 the drive sprocket I9 is shown fixed to the stub axle 17. As the drum 13 turns the drum flange IS, the shock absorber M, the stub axle I7, and sprocket I9 must turn developing a pull in endless chain 20 and a rotary motion in sprocket 21. A chain-tensioning device(s) common to the art is not shown. Chain cover 22 protects the chain and sprockets from the elements and collision with foreign objects and guards personnel working close by from contact with the moving chain or sprockets. With reference to FIG. 2 sprocket 21 is fixed to the input shaft of multiple-gear-type speed increaser 23 and the forced rotary motion is transferred through the speed increaser 23 to the input side of the centrifugal clutch 2d. When the speed on the input side of the centrifugal clutch .reaches the predetermined engaging speed the clutch engages and the rotary motion is passed through the shaft 25 connecting the input side of slip clutch 26 and the output side of the centrifugal clutch 2 1. The slip clutch is normally engaged and the input side drives the output side through friction members at the same speed and it drives shaft 28 which is journaled on

bearings

27 and 30. The slip clutch 26 is the type that can be disengaged manually with local or remote control to make it convenient to tow the roller from one working area to another at speeds well above the rated working speeds without overheating the friction members of the slip clutch 26. When the roller is stopped the driving side of the centrifugal clutch 24 stops and disengages from the driven side but the inertia energy in the rotating vibrator element continues to rotate said driven side of the centrifugal clutch 24l until the energy is used up. Shaft 2% supports and drives centrifugal brake 29 and pulley 3ll. Centrifugal brake 259 stops the shaft 2% and causes the slip clutch 26 to slip when the recommended limiting towing speed is exceeded. This limits the centrifugal force that can be developed and thus protects the bearings I3 and 53 shown in FIG. 3 which journal the vibrating element SI. The pulley 31 being fastened to shaft 28 turns with the engaging of the centrifugal clutch 24 and develops a pull in endless belt 32 which applies a force to pulley 33 and turns it. lBelt guard 37 protects the belt and pulleys from the elements and collision with foreign objects and guards personnel working close by from contact with the moving belt or pulleys. Pulleys 31 and 33 could be the adjustable type so the speed ratio between them could be changed to further regulate the vibrator element speed. The belt is kept tight by a belt-tightening device(s) common to the art which are not shown. Pulley 33 is firmly fastened to shaft 38 which is joumaled in bearings 39 and 40 whose outer races are finnly fixed to the interior diameter of stub axle 34 which is bolted to the drum flange 50 and vibrates and rotates with the drum. This stub axle which turns in bushing 42 as the roller drum rotates supports this side of the frame and drive train through bushing 42 which is a pressed fit in shock absorber mounting plate 44 and through the multiple shock absorbers 43. which are bolted to both the mounting plate 44 and spacers 36 which are welded to the frame side member 35. Spacers 36 location can be seen in FIG. 2 and FIG. 3 showing symmetrical mounting about the stub shaft 34. In this embodiment four shock absorbers 43 are mounted between mounting plate 44 and four spacers 36. A single shock absorber similar to the shock absorber on the left-hand side of FIG. 3 could be used. Returning now to the drive train the drive shaft 38 is connected to the splined end of the vibrator element which is the eccentric shaft 51. As the drive train moves and the centrifugal clutch 24 is engaged the vibrator element 51 is forced to turn. The vibrator element is joumaled in self-aligning

bearings

48 and 53 shown in FIG. 3. The force generated as the rotating vibrator element rotates is transferred to the drum 3 through

bearings

48 and 53 and bearing housings 47 and 54 moves the whole drum assembly in a modified circular pattern vibrating, shaking, and pounding the surface that the roller drum is being towed on. The

shock absorbers

14 and 43 react to this motion and isolate the frame 12 from a large percentage of this vibrating motion.

HYDRAULIC POWEROPTIONAL EMBODIMENT In FIG. 4 the sprocket 70, speed increaser 71, and centrifugal clutch 72, are similar to those shown in the preferred embodiment in FIG. 2 and are driven by an endless chain in a similar manner as in the preferred embodiment. The hydraulic pump 73 and the hydraulic motor 74 are joined together with hydraulic lines 78 and 79 to transmit highand low-pressure oil as in a hydrostatic circuit. The motor 74 and pump 73 are also connected with a case drain line 77 which is connected through the pump case to case drain line 81 from pump to reservoir. The pump 73 is connected to reservoir 80 through line 76 which supplies make up oil to the closed loop circuit as needed. The pump 73 is forced to rotate and displace hydraulic fluid to activate the motor 74 and rotate the motor drive shaft when the roller is pulled at sufficient speed to engage the driven side of centrifugal clutch 72. The motor 74 is fastened to frame side 35 and drives pulley 83. With reference to FIGS. 2, 3, and 4 the vibrator element 51 is rotated when pulley 83 drives an endless belt similar to endless belt 32 which drives pulley 33 as in the preferred embodiment.

Pulleys 83 and 33 in another embodiment could be of the type in which the pitch diameter is adjustable wherein the rotating speed ratio between the pulleys is adjustable. This would allow for a change in vibrating frequency and generated centrifugal force if such a change was desirable.

Multiple embodiments are available to the designer with the use of hydraulic power transfer. Vane-, gear-, and piston-type pumps and motors could be used to transfer the available power. Piston-type pumps and motors of a variable nature are particularly adaptable because of the motor shaft speed control that is possible through varying the displacement of the pump or motor or both. For instance in FIG. 4 a variable displacement pump 73 could be adjusted to a neutral position so that no oil would be circulated regardless of the output speed of the speed increaser. On the other hand when towing speeds were restricted the pump could be adjusted to its maximum displacement to bring the vibrator element up to speed. Simple manual or sophisticated automatic speed controls can be used to control the speed of the vibrator element by changing the displacement of the pump or motor or both pump and motor.

When using gearor vane-type pumps and motors speed regulation could be made by the use of a priority-type flow divider in the high-pressure line between the pump and motor.

The location of the motor 74 is also a variable which constitutes another embodiment. With reference to FIG. 3 said motor could be mounted on a mounting plate similar to 44 concentric to the drum and drive the vibrator element 51 through a drive coupling similar to 41. This would eliminate the

pulleys

31 and 33 and belt 32 shown in the preferred embodiment. The motor would vibrate with the drum but would be stationary to the drum relative to the drum rotation.

MULTIPLE SPEED TRANSMISSIONOPTIONAL EMBODIMENT In FIG. 5 the sprocket 90, speed increaser 9l, centrifugal clutch 93, slip clutch 94, and centrifugal brake 96 are similar to those shown in the preferred embodiment. The transmission 92 turns the centrifugal clutch 93 which turns the slip clutch 94 which slips only when the centrifugal brake 96 is engaged by excessive speed in the shaft 95. The shaft is joumaled in the bearing 97 and bearing 98 and drives pulley 99 which drives an endless belt similar to endless belt 32 in the same manner as pulley 31 in FIG. 2 which in turn drives pulley 33 and vibrator element 51 as shown in FIG. 3 as in the preferred embodiment.

Pulleys

99 and 31 in another embodiment could be of the type in which the pitch diameter is adjustable wherein the rotating speed ratio between the pulleys is adjustable. This would allow for a change in vibrating frequency and generated centrifugal force if such a change was desirable.

The purpose of the multispeed transmission 92 in the drive train is to adjust the drive train speed ratio to adapt to a range of towing speeds. When a change in towing speed is required the effective ratio through the transmission is changed by local or remote control to keep the output speed of the transmission 92 nearly the same in all towing speeds. This keeps the vibrator element speed in the predetermined desired range. This increases the versatility of the roller and makes it easily adaptable to different compaction production requirements where different towing speeds are required or desirable.

ELECTRIC POWER-OPTIONAL EMBODIMENT In FIG. 6 the sprocket 100, speed increaser 101, centrifugal clutch 102 are similar to those shown in the preferred embodiment in FIG. 2 and are driven by an endless chain in a similar manner as in the preferred embodiment. The electric generator 103 is driven by the centrifugal clutch I02 and transmits power through power lines 104 to motor I05 which is mounted to the frame by outboard. bearing housing 106 and drives pulley 108 through shaft 107. Pulley 108 drives pulley 33 and vibrator element 51 as shown in FIG. 2 and 3 through an endless belt similar to 32 shown in FIG. 2 as in the preferred embodiment.

Limiting speed control for the generator in this embodiment is dependent on a fixed speed limit of the towing tractor. The tractor speed is limited through the method of instruction to the vehicle operator or through a mechanical device attached to the vehicle transmission control.

Another embodiment would include a slip clutch and a centrifugal brake mounted between the centrifugal clutch I02 and generator 103 to limit the input speed to the motor as the speed of pulley 31 is limited in the preferred embodiment.

I have shown and described how my invention works, how it is new, and the benefits of my invention compared to the current state of the art. I have shown optional embodiments as well as a preferred embodiment showing drive trains made from several combinations of power transfer devices. It is understood that other combinations of power transfer devices not shown could be used in this new-type drive train. The rearrangement of components or additions and deletions of components in such a friction-driven drive train will not change the basic new idea described in this specification.

I claim the following as my invention:

1. A towed vibrating roller with A. a rotatable roller drum;

B. a frame;

C. means connecting the frame and the drum;

l). a rotatable vibrator element journaled in said roller drum;

E. a drive train drivingly connecting said roller drum to said vibrator element;

F. speed-increasing means driven by said drum included in said drive train;

G. a clutch driven by the speed-increasing means and drivingly connected to the vibrator element which is engaged when the required speed of vibration is obtained.

2. A towed vibrating roller as in claim wherein the drive train includes a multiple speed transmission between the speed increaser and the centrifugal clutch so that the speed ratio between the roller drum and the vibrator element may be changed by changing the effective ratio of the transmission.

3. A towed vibrating roller as in claim 1 wherein the power train includes a hydraulic pump driven by the speed increaser and clutch and a hydraulic motor driven thereby which is coupled to said rotatable vibrator element.

4. A towed vibrating roller as in claim 1 wherein the power train includes an electric generator driven by said speed increaser and clutch and electric motor powered thereby and coupled 'to said rotatable vibrator element.

5. A towed vibrating roller with,

A. a rotatable roller drum;

B. a frame;

C. means connecting the frame and the drum;

l). a rotatable vibrator element joumaled in said roller drum;

E. sprocket means driven by said roller drum;

F. means coupling the sprocket to a speed increaser;

G. a driven shaft;

ill. a centrifugal clutch between said speed increaser and the driven shaft which is engaged when the required speed of vibration is obtained.

l. a pulley on the end of said driven shaft;

J. coupling means between said pulley and said rotatable vibrator element.

6. A towed vibrating roller as in claim 5 wherein the power train includes a disconnectable-type slip clutch between said centrifugal clutch and the driven shaft that can be disengaged so that the roller can be moved at any speed without activating the vibrator element.

7. A towed vibrating roller as in claim 6 wherein the power train includes a centrifugal-type brake between said disconnectable-type slip clutch and the pulley on the end of the driven shaft which limits the speed of the pulley coupled to the rotatable: vibrator element.

Claims

1. A towed vibrating roller with A. a rotatable roller drum; B. a frame; C. means connecting the frame and the drum; D. a rotatable vibrator element journaled in said roller drum; E. a drive train drivingly connecting said roller drum to said vibrator element; F. speed-increasing means driven by said drum included in said drive train; G. a clutch driven by the speed-increasing means and drivingly connected to the vibrator element which is engaged when the required speed of vibration is obtained.

2. A towed vibrating roller as in claim 1 wherein the drive train includes a multiple speed transmission between the speed increaser and the centrifugal clutch so that the speed ratio between the roller drum and the vibrator element may be changed by changing the effective ratio of the transmission.

4. A towed vibrating roller as in claim 1 wherein the power train includes an electric generator driven by said speed increaser and clutch and electric motor powered thereby and coupled to said rotatable vibrator element.

5. A towed vibrating roller with A. a rotatable roller drum; B. a frame; C. means connecting the frame and the drum; D. a rotatable vibrator element journaled in said roller drum; E. sprocket means driven by said roller drum; F. means coupling the sprocket to a speed increaser; G. a driven shaft; H. a centrifugal clutch between said speed increaser and the driven shaft which is engaged when the required speed of vibration is obtained. I. a pulley on the end of said driven shaft; J. coupling means between said pulley and said rotatable vibrator element.

7. A towed vibrating roller as in claim 6 wherein the power train includes a centrifugal-type brake between said disconnectable-type slip clutch and the pulley on the end of the driven shaft which limits the speed of tHe pulley coupled to the rotatable vibrator element.