US2232842A - Vibratory compactors - Google Patents

Description

Feb. 25, .1941. F G. DQUGLASS 2,232,842

VIBRATORY COMPACTOR Filed Jly 22, 1958 AUORNEY.

Patented Feb. 25, 1941 VIBRATORY COMPACTORS Forrest G. Douglass, Los Angeles, Calif., assgnor to Viber Company, a corporation of California Application July 22, 1938, Serial No. 220,685

7 Claims.

This invention relates to vibrators for concrete, and in particular to a vibrator having a flexible, semi-rigid casing suitable for insertion in concrete.

An object of the invention is to provide a vibrator for concrete in which the insertible portion is semi-rigid. Another object is to provide a semi-rigid conduit for a flexible drive shaft. Still another object is the provision of an insertible vibrator for concrete having a portion of the insertible casing of limited flexibility. Another object is to provide a vibrator tube of sufficient rigidity for insertion in mass concrete by handles attached to the motor.

These and other objects will be apparent from the description and the accompanying drawing in which Fig. 1 shows in elevation one form of my vibrator having a semi-rigid portion in its casing; Fig. 2 shows in section, partly in elevation, a preferred form of my invention; Fig. 3 shows a section taken on the line 3--3 of Fig. 2; Fig. 4 shows in detail the Wire lacing used in constructing the semi-rigid portion of my vibrator tube.

In general, my vibrator comprises a tubular casing having a rigid end portion 2l and a semirigid portion 22 adjacent a motor 23 having handles 24. The motor shaft 25 is operatively attached to a coiled spring flexible drive shaft 26 by the key coupling fixture 2l. At the opposite end of the exible drive shaft 26 is attached a similar key coupling xture 28 which engages the end of the rigid eccentric shaft 29 having an eccentric weighted part 33 mounted between bearings 3l held within the rigid casing portion 2l. The semi-rigid casing portion 22 is attached at its one end to the motor housing 32 by bolts 33 in the terminal fixture 34, and to the other end to the rigid casing 2| by the threads 35 on the end of the other terminal xture 36.

The semi-rigid portion 22 of the tubular casing has an inner element consisting of a spirall'y wound wire 4l which serves as a bearing to enclose the exible shaft 26. The terminal fixtures 34 and 36 are attached to this Wire spiral 4I by insertion and fastening of the Wire coils in cylindrical openings in the fixtures. overlying the spil-ally wound wire 4l is a flexible, inextensible, non-collapsible tube 42 of spirally wound metallic strip commonly known as exible steel tubing or interlocking armoured tubing. This armoured tubing 42 is seated in the terminal fixtures Within recesses 43 and holds the fixtures at fixed distances apart.

Upon this exible steel tubing 42 is stretched tubular wire lacing 44 made up of spirally braided wires. In order to permit only a small amount of bending, or flexibility, the lacing is madeso that the pitch angle or helical angle of the Wire strands is about fifteen degrees. Greater fiexibility is attained by increasing the pitch angle. This tubing, when drawn down tightly around the flexible steel tubing, which forms a noncollapsible circumiicial base, and when attached in tension between the terminal fixtures 34 and 36, permits flexibility of the whole assembly but resists or eliminates elongation. The Wire lacing 44 immediately adjacent the interlocking tubing 42 is held in tension by engagement in its meshes with teeth or projections 45 on the exterior surfaces' of the terminal fixtures34 and 36. Tie wires behind the teeth and around the lacing give stronger attachment.

To hold the tensioned Wire lacing in close contact with the flexible steel tubing, and thus prevent buckling and breaking of the individual wires, a fabric strip 46, preferably rubberized or coated with a rubber-like cement, iswound in overlapping spirals on the lacing, and at-` tached to the terminal fixtures by wire ties. `To produce greater strength and semi-rigidity, additional alternate layers of wire lacing and spirally wound fabric are superimposed over the others, as shown at 41 and 4B.

A final outer layer of rubber 49 is vulcanized under the collars or flanges of the terminal xtures 34 and 36, and over the surface, to seal the .whole semi-rigid casing 22 against moisture.

In the vibration of concrete masses, where the vibrator tool is manually thrust, endwise, into the mass, rigid tubes encasing the eccentric weight and rigidly attached to the motor housing have been used, the handles on the motor serving to guide the tubular portion into the concrete. For this service, the device must, for facility in operation, be light enough in weight to be handled by one man. Since usually large masses of concrete are to be vibrated, a very considerable amount of power is required,v and the motor Weight may be reduced only by increasing the rotational or vibrational speeds. Operating speeds approaching 10,000 R. P. M. are frequently employed, and at these speeds, vibration of the handles has heretofore seriously affected the length of time that a workman could hold and operate the machine. While flexible shafts with protective casings have been heretofore employed between the motors and they vibrator casing, these have been so flexible that the operator was unable to guide the placement of the vibrator tube, or thrust it into a pile of concrete, and this type of tool has not been very satisfactory for spreading and compacting masses or piles of concrete, as in mass construction. The use of the semi-rigid tube intermediate the rigid casing enclosing the eccentric weight, or other vibrator mechanism, and the motor, has eliminated the vibration of the handles and the motor, while still providing a tubular portion stiff enough to be manually thrust into a pile of concrete, or accurately guided to positions where compaction was desired. It has also greatly increased the life of the bearings and decreased the trouble due to metal crystallization in the shaft and casing when these are not so flexibly attached to the motor.

The structure described provides a semi-rigid tubular vibrator which when supported in a horizontal position from the motor or handles, will bend not more than about l0 to 20 degrees, as indicated diagrammatically on Fig. 1 as angle a.

While I have described a preferred embodiment of my invention, I do not wish to be limited to this particular form, but restrict my invention only in so far as is necessitated by the prior art andby the .spirit of the appended claims.

I claim:

1. A unitary vibrator-y compacting device comprising, in combination, a motor in a motor housing provided with handles Ifor manipulating the device; a vibrator casing of limited flexibility connected to said motor housing and having a rigid end casing portion containing rotary vibratory mechanism, and a semi-rigid casing portion intermediate said motor housing and said rigid end Casing portion containing a flexible drive shaft connecting said motor and said vibratory mechanism, said semi-rigid casing portion having sucient rigidity to permit accurate guiding or manipulation of the vibrator casing by means of saidhandles while having sufficient flexibility to permit bending or displacement of said casing relative to said motor housing through a substantial arc.

2. A unitary vibratory compacting device oomprising, in combination, a motor in a motor housing provided with handles for manipulating the device; a Vibrator casing of limited exibility connected to said motor housing and having a rigid end casing portion containing rotary vibratory mechanism, and a semi-rigid casing portion intermediate said motor housing and said rigid end casing portion containing a flexible drive shaft connecting said motor and said vibratory mechanism, said semi-rigid casing portion being constructed of material resistant to the transmission of vibrations and of a limited rigidity designed to permit a bending or displacement of said vibrator casing relative to said motor housing, of the order of and not substantially exceeding approximately twenty degrees from normal position.

3. A unitary vibratory compacting device comprising, in combination, a motor in a motor housing provided with handles for manipulating the device; a vibrator casing of limited flexibility connected to said motor housing and having a rigid end casing portion containing rotary vibratory mechanism, and a semi-rigid casing portion intermediate said motor housing and said rigid end casing portion containing a flexible drive shaft connecting said motor and said vibratory mechanism, said semi-rigid casing portion being constructed of tubular Wire lacing held in tension lengthwise of said casing portion and having a limited rigidity designed to permit a bending or displacement of said vibrator casing relative to said motor housing, of the order of and not substantially exceeding approximately twenty degrees from normal position.

4. A unitary vibratory compacting device comprising, in combination, a motor in a motor housing provided with handles for manipulating the device; a vibrator casing of limited flexibility connected to said motor housing and having a rigid end casing portion containing rotary vibratory mechanism, and a semi-rigid casing portion intermediate said motor housing and said rigid end casing portion containing a flexible drive shaft connecting said motor and said vibratory mechanism, said semi-rigid casing portion being constructed of a hollow flexible noncollapsible core member providing a passage for the flexible drive shaft, tubular wire lacing overlying said core member and held in tension longitudinally of said casing portion and binding means adapted to hold said lacing tightly against said core member, said construction having a limited rigidity permitting a bending or displacement of said vibrator casing relative to said motor housing, of the order of and not substantially exceeding approximately twenty degrees from normal position.

5. A unitary vibratory compacting device according to claim 3, wherein the wire of the tubular lacing is coiled around said core at a helical angle of approximately fifteen degrees, for the purpose indicated.

6. A unitary vibratory compacting device according to claim 4, wherein the wire of the tubular lacing is coiled around said core at a helical angle oi approximately fifteen degrees, for the purpose indicated.

7. A unitary vibratory compacting device comprising, in combination, a motor in a motor housing provided with handles for manipulating the device; a vibrator casing of limited flexibility connected to said motor housing and having a rigid end casing portion containing rotary vibratory mechanism, and a casing portion intermediate said motor housing and said rigid end casing portion containing a flexible drive shaft connecting said motor and said vibratory mechanism, said intermediate casing portion having a sheathing oi individually ilexible elements held in tension between said motor housing and said rigid casing portion to render said sheathing and said casing portion suiiciently semi-rigid to permit accurate guiding or manipulation of the vibrator casing by means of said handles while having sufficient flexibility to permit bending or displacement of said casing relative to said motor housing through a substantial arc.

FORREST G. DOUGLASS.

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