US 2598895 A
Description (OCR text may contain errors)
June 3, 1952 H. DREYER FLEXIBLE DRIVE MEANS FOR CONCRETE VIBRATORS Filed June 27, 1947 .|.l|| I- @4V/Mm JNVENToR. HERBERT DREYER H-arnys Patented June 3, 1952 FLEXIBLE DRIVE MEANS FOR CONCRETE vVIB RATORS Herbert Dreyer, Los Angeles, Calif. Application 'Junev 27, 1947, Serial N0. 757,497 A 6 claims. (ol. 64-4) My invention relates to exible drive means for concrete vibrators. Concrete vibrators are devices which are lowered between the forms ofv a wall or other structure in the course of pouring concrete for the purpose of vibrating the fresh concrete thereby to consolidate and increase the density and strength of the concrete. Such devices are suspended'V from flexible drive cables which not only supply the rotary motion to eccentric devices or other vibrating mechanisms contained in the head of the vibrator, but also serve as the means for lowering, raising and manipulating the vibrator in and around reinforcing and other obstructions. As a consequence, such drive cables are ysubjected to extreme abuse.
Included in the objects of my invention are:
First, to provide a flexible drive for concrete vibrators which isparticularly adapted to withstand the abuse inherent in the use of concrete vibrators. g
Second, to provide a flexible drive for concrete vibrators which may be made in sections so that the length of the flexible drive means between the motor and the vibrator head may be varied to meet the conditions of use.
Third, to provide a flexible drive which employs a coupling structure so arranged that both the sheath or housing and the drive shaft have corresponding coupling elements which may lbe readily connected or disconnected; or, when desired, the drive shaft may be removed or inserted into the entire length of the coupled sections of sheathing without disconnecting the coupling elements of the sheathing or the drive shaft, thereby facilitating greasing and servicing of the flexible drive.
Fourth, to provide a sectional ilexible drive means for concrete vibratorswhich eliminates the need of special ibearing units interposed between adjacent sections, instead, the coupling provided at the ends of each flexible housing Isection forms a bearing in which is journalled the couplings which join the sections of flexible shaft.
With the above and other objects in View, reference is directed to the accompanying drawings in which: Y
Figure l is an elevational view of my flexible drive means shown in association with a motor drive unit and vibrator head.
Figure 2 is an enlarged fragmentary sectional view through 2-2 of Figure 1 with portions shown in elevation, and showing particularly lthe coupling means which join adjacent sections of the flexible shaft and shaft housing.
Figure 3` is a ,fragmentary sectional view throught-3 of Figure 1 with the coupling member of the `flexible drive Ain elevation..
Figure 4 is a further enlarged transverse sectional view through 4-4 of Figure 2.
Figure 5 is a fragmentary sectional view showing a modied form of end mandril which may be employed in my flexible drive means.
The complete concrete vibrator includes motor I, flexible drive units 2 and 3 which may be used individuallyr or connected, or for special occasions additional flexible drive units may be provided.V The lowermost drive unit is joined to a vibrator'head 4;
In operation the motor unit is held Iby the operator or suspended from a suitable support and the vibrator headis forced into newly poured concrete and in and around reinforcing. This involves a considerable twisting and turning of the flexible drive units as the vibrator head is raised and lowered and moved from one place to another in the concrete.
Each exible drive unit includes a flexible housing 5. The housing includes a steel coil 6, the ends of which are adapted to t in a mandril 'l having a counterbore 8. The opposite` or extended end of the mandril 1 is threaded, as indicated by 9. The steel coil is wrapped with servings of-wire braiding I0 and rubber or synthetic rubber impregnated fabric I I, arranged alternately. All or some of the servings .may extend the entire length of the steel coil. -Itis preferred, however, to provide gradually decreasing stiffness from the mandril toward the mid-portion of the exible housing. Consequently, at least the outer servings of wire braiding IU may terminate at different distances from the mandril 1. The servings arebraised or soldered to the mandril, as indicated lby I2. For this purpose, the mandril may be provided with one or more channels into which the bonding metal is flowed, and, in addition, the mandril may have outwardly pressed tongues I3 which press through the strands comprising the wire braiding. The servings are encased in an outer molded serving or cover of rubber, synthetic rubber, or other yieldable material. The rubber cover I4 is so molded as to expose the threaded end 9 of the mandril.
Each mandril is adapted to be screwthreaded into a tubular coupling I5. The extended ends of the couplings I5 may Hoe provided with internally threaded sockets I6 or mating threaded pins I1 so that the couplings of adjacent sections of flexible housing may be joined together as shown in Figure 2,A or joined to the casing of themotor drive unit or to the casingof the V`vibr1v-,0r headv Each tubular coupling I is provided with an integral sleeve I8 of approximately the same length as the mandril 1. It is preferred to mold Y the covering I4 to a diameter equal to the outside diameter of the tubular coupling and then, prior to assembly, grind the surface of the molded covering I4 until the end will slide into the sleeve I8 and permit the mandril 'I to be threaded into the coupling I5. It is preferred-that the `threads which join the mandril 1 to the tubular coupling I 5 and the threads provided in the sockets I6 and Y pinsV Ilbe left handed threads, or at least be threaded in the same direction and in oppositionV to the torque which may be transmitted from'the' drive cable (to Vibe described hereinafter) lto the ilexible housing.
Each flexible housing 5 receives ardrivejcable I9. Attached to each end of each drive cable I5 is a coupling member 20. The coupling members 'capable of journa'lling the coupling members 20.
Thebores of the tubular couplings `I5 alone are of suicient length rto `constitute the bearings for the Y"coupling members therefore, if desired, the bores of l'the mandril 1 mayV be enlarged slightly and reduce the tolerance with which the mandrils need be fitted into the tubular Scouplings.'V
It iis icustomary'to provide a squared or 'keyed shank 24 on the :lowermost coupling'member 20, which shanlc is adapted yto 'ilt'iinto .a `4correspondingly formed socket within -a stem 25 provided on the rotating element 26 contained within the vibrator head 4. With this arrangement, it is possible to withdraw or insert 'the drive cable without disconnecting the vibrator head from the adjacent flexible drive unit. Y
' 1t will be observed 1that iby employing thetubular couplings I5 as Vbearings for the coupling members y20, the needfof any 'bearing vmounted adaptor Vfitting -between adjacent flexible drive units is eliminated. Consequently, it is Vpossible when servicing or greasing `any flexible drive means to Withdraw the entire 4set of drive cables without separating fthe tubular-couplings or coupling members and to reassemble the combined drivecables-into the `flexible yhousing after-greasing or servicing. It is not necessary that the drive cables be entirely removed for high lpressure lubricant may lbe forced between the cable and the housing, particularly if the cable vis raised until the coupling members are within the steel coil 6. Under these conditions, the llubricant'mayfbe forced around and past the'coupling members Without difculty.
When itiis desired to-shorten vor lengthen the flexible drive 'means it is merely necessary 'to unthread the yadjacent couplings VI5 exposing the Acoupling members 2.0 which are then unthreaded. rIEhe threads .of .the tubular-coupling members may become damaged service, Valthough the flexible housing/maybein good .ccn-
dition. Conversely, the housing'may'fbedamaged without damage to the tubular couplings. By reason'of the fact'that'th'e"tubularfcouplings are connected by threads vtoV the mandrils "I, it I-isv Many other embodiments of the invention may be resorted to without departing from the spirit of the invention.
1. A flexible drive means for connection between a motor drive unit and a concrete vibrator head, said drive means comprising: a flexible housing including metal reinforcing servings and molded servings forming a ilexible tube; tubular end mandrils secured to the metal servings of said flexible housing, said mandrils having threaded extremities; tubular couplings threaded to receivev said mandrils and including sleeves overlying the extremities of said flexible housing; and a flexible drive shaft axially displaceable and rotatably mounted within said flexible housing.
2. A flexible drive means for connection between a'motor drive unit and a concrete vibrator head, said drivemeans comprising: a flexible housing including metal reinforcing servings and `molded servings forming a flexible tube; tubular and mandrils secured to the metal servings of said flexible housing, said mandrils having threaded extremities; tubular couplings threaded to receive said mandrils and including sleeves overlying the extremities of said ilexible housing; a lexible drive shaft in said flexible housing; and coupling members at the extremities of vsaid ilexible drive shaft, journalled in and by said tubular couplings and axially displaceabletherein. Y
3. A ilexible drive means for connection between a motor drive unit and a concrete vibrator head, said drive means comprising: a sectional ilexible housing, each section `including a flexible tube having metal and non-metal servings, tubular mandrils joined to the extremities of the metal servings of said flexible tube, tubular couplings joined by threaded connections to said mandrils and having sleeves overlying the -extremities vof said flexible tube, said tubular couplings having screwthread means for joining said housing sections end-to-end and to said motor unit and said vibrator head; a sectional ilexible shaft, each section including coupling members for joining sections of said shaft together and to said motor unit and said vibrator head; said coupling members disposed Within and journalled directly by said tubular couplings and axially displaceable therein.
4. A ilexible drive means as set forth in claim 2 wherein clearance is provided between the sections of flexible shaft including said coupling members `and the sections of flexible housing, thereby to permit Apassage of a lubricant from end-to-end of a multiple section drive means, upon axial displacement'ofthellexible shaft coupling members into the "sections of flexible housing. Y Y
`5. A'exible drive means as set forth Ain claim 3 wherein clearance is provided betweenlthe sectionsof yflexible `shaft including said coupling members and the sections of flexible housing, thereby to permit passage of a lubricant from end-to-end of a multiple section drive means, uponaxial displacement of Vtheilexible'shaft couplingmembers into the sections of vvilexible housing.
A6. In Aan' Aapparatus Yoi `the class described: a 'flexible housing including metal reinforcing servings' and moldedservings forming a ilexible tube; tubular end mandrils secured to the `metal servings ofsaidjexiblehou'sing. said mandrils having threaded extremities; and tubular cou- 5 6 plings threaded to receive said mandrils and n- UNITED STATES PATENTS cluding sleeves overlying the extremities of said Number Name Date flexible housing. 2 9
HERBERT DREYER. ,112,004 Wyzenbeek Marx 22, 1 3
5 FOREIGN PATENTS REFERENCES CITED Number Country Date The following references are of record in the 752,264 France le of this patent: