US2043585A

US2043585A - Concrete tamping device

Info

Publication number: US2043585A
Application number: US682196A
Authority: US
Inventors: Philip A Kerwin
Original assignee: CITY OF DETROIT
Current assignee: CITY OF DETROIT
Priority date: 1933-07-26
Filing date: 1933-07-26
Publication date: 1936-06-09
Anticipated expiration: 1953-06-09

Description

June 9, 1936. F. A KERWIN CONCRETE TAMPING DEVICE Filed July 2e,

1935 2 Sheets-Sheet l INVENTOR l?. @nM/'7 ATTORNEYS June 9, 1936.

CONCRETE TAMPING DEVICE VFiled July 26, 1933 P. A. KERWIN 2 Sheets-Sheet 2 ATTORNEYS Patented June 9, 1936 UNITED STATES CONCRETE TAMPING DEVICE Philip A. Kerwin, Detroit, Mich., assigner to City of Detroit, Department of Street Railways,

Wayne County, Mich.

Application July 26, 1933, Serial No. 682,196

5 Claims.

The present invention pertains to a novel machine for tamping concrete and the primary object is to provide means for distributing or placing freshly poured concrete between tracks of a street railway as a uniform consistently dense mass in full contact with the under surfaces of the tracks and in full contact with all exposed surfaces of the ties and plates that support the same.

Another object of the present invention is to provide a machine for tamping freshly poured concrete without causing segregation of the concrete mass by settling the heavier parts thereof, and thus provide a uniformly dense concrete mass that is free from voids or air pockets and which is placed in all crevices and angles of reinforcing members or other devices to be imbedded in the concrete.

Various means and methods have heretofore been used in order to improve the density of freshly poured concrete and in order to cause the concrete mass to be placed beneath the tracks of a street railway and the ties that support the same and in analogous concrete construction Work where steel members are to be imbedded in the concrete, the chief among prior attempts being in the form of means for vibrating the rails or other steel members and thus transmitting vibration to the concrete. With this method the heavier aggregate forming the concrete was caused to settle, and a lighter formation adjacent the under side of the rails or adjacent th-e steel or other imbedded members resulted in a poor or weak support for the rails or other imbedded member after the concrete hardened. Furthermore when stopping operations at night and blocking the concrete as is the usual custom, the concrete thus poured becomes partly set, or is in green condition by the time operations are resumed the next morning, which makes it impossible to vibrate the rails or other imbedded members that extend outwardly from the green concrete into the freshly poured concrete which is a continuation of that poured theday before because that vibration is not only transmitted to the freshly poured concrete, but to the green concrete also and destroys the bearing or support beneath the rails and ties, or other imbedded members, and it destroys the bond between the concrete and the rails or other imbedded members, which causes a pocket to form adjacent the steel imbedded members which when exposed to the weather becomes filled with water with harmful results. In using a device for vibrating the rails, the same cannot be usedexceptwhen it is sufliciently far away from green concrete as to avoid possibility of the vibration reaching the green concrete. It is, therefore, another object of the present invention to provide a machine that may be used to tamp, distribute and place concrete that is poured closely adjacent green concrete without injuring the latter.

Still another object of the present invention is to provide means for tamping freshly poured concrete between tracks of a street railway, without imparting vibration or shocks to the tracks or ties in a manner to destroy their proper alignment, elevation or spacing, or in a manner to loosen spike fastened tracks in cases where wood ties are used.

With the above and other ends in view the invention consists in matters hereinafter set forth and more particularly pointed out in the appended claims, reference being had to the accompanying drawings, in which Figure `1` is a top plan view of the present tamping machine;

l'ig.` 2 is an end elevation;

Fig. 3 is a side elevation;

Fig. 4 is a vertical cross section;

Figs. 5 and 6 are elevations of other forms of tampers. v

Like characters of reference are employed throughout to designate corresponding parts.

The numeral I designates a vehicle frame or chassis having bearings 2 secured to the underside thereof adjacent opposite ends, the bearings being provided to rotatably support the front axle 3 and the rear axle 4. Rubber pads 2 are preferably interposed between the bearings and the frame so that any vibration that is set up on the frame as a result of the operation of mechanism to be described will not be transmitted from the frame to the wheels. 0n the axles 3 and 4 are mounted wheels 5 which are illustrated as having guide flanges that make them suitable for traversing rails or tracks 6. The tracks 6 represent any conventional or well known railway construction and it will be understood that they may be secured in parallel alignment by metallic ties 6 and supporting plates 62 such as illustrated or theymay be secured to wood ties by spikes. It will be understood, although the preferred embodiment of this invention relates particularly to the problem of placing concrete relative to railway tracks, that the present device is adaptable for placing concrete construction work, and that it is not con-V fined to this use alone.

Supported by the chassis I are .vertical guide members 'I within which is slidably mounted a carriage 8 which includes a top plate 9, a bottom plate I0, and I-beams I I for securing said plates in spaced relation in a manner to resist any torsional stress that might be imparted to the carriage 8 by any external forces. Mounted on the plate 9 are pairs of sheaves I2, each pair of sheaves being mounted adjacent opposite ends of the carriage,` and each sheave in each pair being mounted adjacent the sides of the carriage. A cable I3 is trained under each pair of sheaves I2 and each cable has one end anchored as at I4-A in one guide member 'I with its other end secured to a shaft I5 that is mounted in a guide member I on the opposite side of the carriage. The shaft I5 is equipped with a hand wheely I6 so that the same may be manually rotated in order to Wind the cables I3 around the same and thus cause said cables to raise the carriage 8, or unwind said cables so that the force of gravi-ty causes said carriage B to move downwardly.

Bearings II are mounted in each of the plates 9 and I0 and support shafts I8 sol that the same may bereciprocated in a manner to be described. Ony the lower ends of the shafts I8 are mounted cylindrical tampers I9 having their lower ends rounded as at 2l) to eliminateV suction when the same are forced into contact with freshly poured concrete, and to exert a pushing action against the concretelin all directions corresponding to radii of the rounded bottom thereof. A hori zontally extending shaft 2|. is supported in bearings 22 above the platev 9 of the carriage and is rotated through a belt 23 by an electric motor 24 that is also mounted on the plate 9f. The shaft 2I is provided with eccentrics 25 upon which are mounted bearings 26 of connecting rods 21 that are pivotallyl connected as at 28 to the shafts I8.

From the foregoing it becomes apparent that the shaft 2| is caused to; rotate by the motor 24 and rotation of the eccentrics as an-integral part of the shaft causes reciprocal movement ofthe connecting rods 21, and thus. cause'reciprocation of the shafts I8 and of the tampers I9. By rotating, the hand Wheel I6' the shaft I-5 maybe rotated to unwind the cables I3 therefrom and permit the carriage to lo-weruntil the tampers I l-l-extend` beneath the surface of freshly poured plastic concrete 29 as illustrated inl Fig. 4.

The `cams 25, as shown are illustrativer only, and could not be drawn to proper scaleA because their throw is relatively small, and therefore when the tampers are projected beneath the surface of concrete aggregate the electric motor rotates the eccentricsso: as to provide a rapid succession of op-V posed movements of the tampers While the same are; imbedded within thel plastic mass. 'In this Ina-nner the softmass is initially displaced downwardly when the` tampers move below the surface, andas the tampers move upwardly the material tendsfto move back, but rapidity of the tamper movementV prevents such replacement taking place,A and as a result a series of tamping impulses are made effective laterally by a. tendency to displace any material that'might have moved back beneath the tamper during upward movement thereof.

In order to provide for movement of the entire: mechanism longitudinally alongy the tracks E there is provided a stub shaft 30' that is supin ported directly above the axle 4 in a bearing 3|, the` shaft having a hand wheel' 32 on one end that facilitates manual rotation thereof, and a sprocket 33 on its other end that is'connected by a chain 34 to a sprocket 35 on the axle 4. Thus by manually rotating the hand wheel 32 the axle 4 and wheels 5 thereon may be caused to rotate.

Referring to Fig. 2 where the present device is illustrated in one stage of the concrete distributing and placement operation, it will be noted that the freshly poured concrete 29 is rst poured between the tracks 6 and the action of the tampers I9 resulting from their vertical reciprocation is to force or push the concrete under the cross members or ties 6 and under the plates 62 so that it comes up and falls in Contact with the outside surfaces of the rails 6 and on top of the portions of the ties 5 and plates 62 which extend outside the rails as designated generally at 36. It will be noted that the tampers at no time contact with the rail and that while the concrete is in plastic form thev pushing action of the tampers does not cause vibration to be transmitted through the concrete to the rails.

In 5 therey is illustrated a tamper head 31 having` a conical bottom 38 which when reciprocated in aconcrete mass tends to displace the same laterally, rather than downwardly and in Fig. 6 there is illustrated a tamper head having a semi-spherical bottom 39, which when reciprocated in a, concrete mass tends to displace the material in radial directions.

Although a specific embodiment of the present invention has been illustrated and described it is to be understood that various` changes may be made in the details of construction without departing from the spirit of the invention as set forth in the appended claims, and such changes are contemplated.

WhatI claim is:

l. The combination. with a wheeledv truck, of a vertically movable carriage supported therein, a shaft rotatably supported by said carriage and having a plurality of eccentri'cs thereon, a plurality of vertically reciprocable shafts mounted in said carriage, tampers mounted on the lower ends of' said plurality of shafts, connecting rods individually connecting the upper ends of the shafts to said eccentrics, said eccentrics having a comparatively small throw whereby they impart a relatively short stroke to said connecting rods, means for rotating said eccentric bearing shaft at a high rate of speed whereby to reciprocate said tampers at a comparatively high rate, and means for moving saidY carriage to position said tampers with respect to wet concrete whereby said tampers remain beneath the surface of said wet concrete during said reciprocations.

2. The combination with a wheeled truck, of a vertically movable carriage supported therein, a shaft rotatably supported by said carriage and having a plurality of eccentrics thereon, a plurality of vertically reciprocable shafts mounted in said carriage, tampers mounted on the lower ends of said plurality of shafts, connecting rods individually connecting the upper ends of the shafts to said eccentrics, said eccentrics having a comparatively small throw whereby they impart a relatively short stroke to said connecting rods, means for rotating said eccentric bearing shaft at a high rate of speed whereby to reciprocate said tampers at a comparatively high rate of speed, vibration absorbing means between said carriage and the Wheels on said truck, and means for moving said carriage to position said tampers with respect to wet concrete whereby said tampers remain beneath the surface of said wet concrete during said reciprocations.

3. The combination with a wheeled truck, of

vertical guides, a carriage slidable in said guides, tampers mounted for reciprocal movement in said carriage, means on said carriage for reciprocating said tampers whereby the stroke thereof is comparatively short, means for operating said reciprocating means at a comparatively high rate of speed, and means for moving said carriage with respect to wet concrete whereby said tampers remain beneath the surface of said Wet concrete during said reciprocations.

4. The combination with a Wheeled truck, of a vertically movable carriage supported therein, a shaft rotatably supported in said carriage and having a plurality of comparatively small throw eccentrics thereon, means for rotating said shaft at a comparatively high rate of speed, connecting rods individually connected to said eccentrics, tamper heads, and vertically reciprocable shafts mounted in said carriage and individually connecting said connecting rods to said tamper heads, said eccentrics being adapted to impart comparatively high speed and comparatively short reciprocations to said tampers, and said vertical shafts being adapted to support said tampers with respect to wet concrete whereby the tampers remain beneath the surface of said Wet concrete during said reoiprocations.

5. The combination with a wheeled truck, of a vertically movable carriage supported therein, a shaft rotatably supported in said carriage and having a plurality of comparatively small throw eccentrics thereon, means for rotating said shaft ata comparatively high rate of speed, connecting rods individually connected to said eccentrics, tamper heads, bearings Xedly positioned in said carriage, and vertically reciprocable shafts mounted in said bearings and individually connecting said connecting rods to said tamper heads, said eccentrics being adapted to impart comparatively high speed and comparatively short reciprocations to said tampers, and said vertical shafts being adapted to support said tampers with respect to wet concrete whereby the tampers remain beneath the surface of said Wet concrete during said reciprocations.

PHILIP A. KERWIN.