US2785866A

US2785866A - Machine for wrapping concrete containers with wire

Info

Publication number: US2785866A
Application number: US282492A
Authority: US
Inventors: Vogt Kurt
Original assignee: Bureau BBR Ltd
Current assignee: Bureau BBR Ltd
Priority date: 1951-04-16
Filing date: 1952-04-15
Publication date: 1957-03-19
Anticipated expiration: 1974-03-19

Description

March 19, 1957 K, VOGT 2,785,866

MACHINE FOR WRAPPING CONCRETE CONTAINERS WITH W RE Filed April 15, 1952 2 Sheets-Sheet l v March 19, 1957 K. VOGT 2,785,866

MACHINE FOR WRAPPING CONCRETE CONTAINERS WITH WIRE Filed April 15, 1952 2 Sheets-Sheet 2 -//l l /V70/? K0177 1 067 United States Patent MACHINE FOR WRAPPING CONCRETE CONTAINERS WITH WIRE Kurt Vogt, Beinwil am See, Switzerland, assignor to Bureau BBR, Zurich, Switzerland Application April 15, 1952, Serial No. 282,492

Claims priority, application Switzerland April 16, 1951 7 Claims. (Cl. 242-7) The present invention relates to a machine for wrapping concrete containers with steel wire. It is known practice to wrap with steel wire under tensile stress the walls of concrete containers of circular or oval crosssection which are subjected in service to an internal pressure, so that a tangential compressive stress is produced in the concrete. In these machines a frame with a platform on which a reel of wire and a winding drum or capstan are mounted circles round the container, the winding drum rolling along a cable stretched round the container and over the winding drum, the platform being thus adjusted in height so that a Wire uncoiling from the reelhwraps helically round the container with the desired pitc The tensile stress on the wire is produced in known machines of this type by the wire being drawn through a. drawing die which reduces its cross-sectional area. These machines consume a great deal of power in order to produce the tensile stress on the wire and require the leading end of a coil of the wire being unwound to be preliminarily drawn to lighter gauge so that it can be drawn through the die and secured to the container. In another known machine the wire is drawn along between clamping plates. In both cases the resultant friction is converted into heat which has to be eliminated by coolants and in both methods the joining of the trailing end of an uncoiling coil of wire to the leading end of a new coil necessitates an interruption of production because the thickenings occurring at the joints can pass neither through the die nor through a clamping device.

The drive power of the motor in such machines is computed from the wrapping speed of and the tensile force exerted by. the wire, plus all frictional losses. If, for instance, a steel wire of mm. gauge is wrapped under a tensile stress of 2000 kilos and at a speed of 1.5 metres per second round the wall of a container, the net power required for wrapping is ZOOOX 1.5

Such machines are therefore rather large, heavy and expensive and necessitate the constant presence of an operator on their platforms.

The object of the present invention is to eliminate these drawbacks. The invention resides in the fact that the wrapping wire tension is produced by the combination of a winding drum with a wrapping wheel or sheave positively connected therewith. The said winding drum and the said wrapping wheel or sheave cooperate with each other so that the rolling travel of the winding drum on the wire cable is greater than the length of the unstressed wire payed oil in the same space of time by the wrapping wheel.

In the accompanying drawings a typical embodiment of the invention is depicted. In the drawings:

Figure 1 shows a machine embodying the invention in front elevational view, partly in section;

R 2,785,866 Patented Mar. 19, 1957 Figure 2 shows the machine of Fig. 1 in plan view, some parts being omitted for the sake of clarity;

Figure 3 shows the machine of Fig. 1 in side elevational view and schematically during operation on a container;

Figure 4 is a sectional View of a sheave utilizable as a wire pay-off means, the coiling diameter being variable; and

Figure 5 shows a sheave utilizable in the invention and constructed as a wire wrapping sheave or wheel.

Referring now more particularly to the drawings, a wheeled chassis 29 is revolvable round the container 31 by means of the arm 2% provided with a bearing or bushing 3i) mounted on the pivot 31a, the latter being disposed substantially on the axial center of the container 31, the running wheels 43 and 44 (Fig. 2) traveling along the outside of the container 31 and serving as guide means for a wrapping frame 37. Mounted on the wheeled chassis 29 is a motor 34 which drives the wormwheel 32, the latter being connected with a bushing 33 which is rotatably mounted in bearings 33a. The shaft 38 is square in cross-section (Fig. 2) and is mounted in the bushing 33 for axial displacement, but not for rotation relative to said bushing. The cable winch 35 may be coupled with and driven by the motor 34 through a gearing or transmission system (not shown) and enables the Wrapping frame 37 suspended from the winch cable 36 to be adjusted in height so as to wrap the wrapping wire 55 round the container at a predeterminable pitch. The

wheels

43, 44 of the wrapping frame 37 rest on the outside of the container 31 (Fig. 3) and the wheels 4411 carry the chassis 29. When the motor is uncoupled the winch can also be hand-actuated by means of a crank. The shaft 38 may consist, for example, of a single element or of a plurality of interconnected jointed elements, or may comprise a tube of square cross-section. At its lower end shaft 38 is coupled to the shaft 39 of the wrapping mechanism, to which latter shaft the winding drum 40 is rigidly secured by means of a key or inany other suitable manner. The wrapping wheel or sheave 41 is mounted for free rotation on the shaft 39 and is connected to the winding drum by the slipping clutch 42.

The wire cable 45 is, as shown in Figure 2, looped in the known manner round the container 31, the winding drum 40 and the tension roller 46, and may be tightened by actuation of the handwheel 47. It will be understood that cable 45 defines a closed loop along which the winding drum 4% rolls when the device is set in motion, thereby guiding the entire wrapping frame 37 along the exterior wall of container 31.

The tension roller 46, the handwheel 47, and the gearwheel 51 are rotatably mounted on the shaft 48, while the gearwheel 50 is keyed to the said shaft. The shaft 48 is toothed at both ends and these teeth at each shaft end mesh with a respective rack. The upper rack 49 secured to wrapping frame 37 is shown in Figure 2 of the drawing. The gearwheel 50, which is keyed to the shaft 48, has one more tooth than the gearwheel 51, which latter is mounted freely on the shaft 48 and engages with its stud 52 a recess in the frame 37 so that said gearwheel 51 cannot turn on its own axis. The handwheel 47, which rotates on the shaft 48, carries a circulating cogwheel 53 which meshes with the

wheels

50 and 51. The tension roller 46 is able to transmit a torque or rotary drive to the handwheel 47 through an engageable and disengageable slipping clutch 54. When the handwheel 47 is turned in the direction of the arrow in Figure 2, the circulating cogwheel 53 rolls along the peripheries of the

wheels

51 and 50 with the result that the latter gearwheel, owing to the difference in its number of teeth, turns by one tooth pitch in the same direction for each revolution of the handwheel 47 and the shaft 48 rolls stantly, in attendance at the machine.

distance between the shafts 39 and 48' increases, with the result that the wire cable 45 can, owing to the large transmissionv ratio, be firmly tightened with little efiort by means of. the handwheel. During the revolution of the frame 37' about the container the slipping clutch 54 re mains in engagement, whereby the cable tension is auto matically maintained at a definite value which can be set on the slipping clutch (by means not shown).

The wrapping wire 55 is guided by a tube 57 from the unwinding reel 56 on to the wrapping wheel or sheave 41, lapped in the known manner several times round the wrapping wheel 41'so that it cannot slip tangentially, and its leading end is secured to the wall of the container. By means of the curved tube 57'the wire is braked so that it runs on to the wrapping wheel 41 under. a slighttensile stress. The said wheel 41 mayv also'be provided at its periphery with a groove of V-shaped cross-section m which the wire lies. if the angle of the V is, adequate,.a lapping angle of less than 360 is sufiicient to secure the wire against tangential displacement on the wrapping wheel.

If the machine isnow set in motion, the winding drum 49 rolls along the wire cable 45, whereby the entire machine is guided along the container wall in the direction of the arrow (Figure l).

Thediameter of the wrapping wheel 41 is smaller than that of the winding drum 4%; If, for instance, the latter performs one revolution, its rolling travel on the wire cable is greater than the length of the untensioned wire unwound in the same space of time by the wrapping wheel. As a result the wire is tensioned between the wrapping wheel and the container Wall. In the event that a predetermined wire'tension adjustable by means of the slipping clutch 42 is exceeded, a relative movement takes place between the winding drum 4t and the wrapping wheel 41.

The said relative movement can be reduced to a minimum by suitable selection of the diameter of the wrapping Wheel.

Owing to the low sliding speed in the slipping clutch 42 the frictional members of the latter heat up only to a negligible extent, so that the slipping clutch torque, once set, remains practically constant, and with it the tensile stress on the wrapped Wire.

Itis also possible to. join the wire coils together in the known manner to form coils of any desired weight or thickness, as the machine-offers no obstacle to the thickened joints as is the case where a drawing die is used. The unwinding reel 56 may also be mounted on. the con nectingarm 29a in the vicinity of. the center ofthe container, with the result that the wheeled chassis 29 is relieved of weight and the resistanceto-travelis diminished. If the coil of wire is sufiiciently long for wrapping the entire container, wrapping may be performed in a single working cycle on a fully automatic basis. It is not necessary, moreover, -or an operator, to be con- When the wrapping frame 37 has reached the desir'edheight, the machine can be stopped by means of a trip (not shown) on the shaft 38 or on the cable 36.

7 The lifting speed of the winch can be progressively increased by known means so that the. pitch of. the turns of wire round the container increases towards the top.

The diameter of the wrapping wheel is preferably made as large as possible so that no, or only minimal, inherent stresses'are set up in the wrapping .wire running on it by the curvature of the wrapping wheel, which stresses; as is-common knowledge, tend to'produce creeping of the tensioned wrapping wire and are therefore disadvantageous.

Further. constructive embodiments of the inventiona are as follows:

The winding drums. and. the'wrapping. wheel may be so interconnected that they cannot rotate relatively to 4 one another, e. g., by both being rigidly keyed to the same shaft. In this case the wrapping wire tension can be regulated by making the wrapping Wheel or sheave adjustable in diameter, as indicated in Figure 4.

in this case the wrapping wheel is made of a stationary wheel part 41a and a displaceable and adjustable wheel part 41b, both parts constituting outwardly diverging peripheral flange or rim portions between which the winding or wrapping wire 55 runs. flange portionswire iiis tensioned', whilewhenwheel part 43b is moved in the direction of arrows A, A upon adjustment of nut -39b= onthreaded" shaft. end: 39a, the tension of wire 55 will be decreased a predetermined value.

Furthermore, thewrappingwheeliand the winding drum. may be made of .l xed diameter and'combined in the form of a stepped drum 46, 41' as shown in Figure 5. It is also possible to provide morethan. one'ste'p, in; which case each step would correspond to-a specifiowiretension.

It is also possible. to make: the winding dl'lLTl or the wrapping Wheeltapered, sothat. accordingtothe axialposition of. the wire or. thecable. a difierent diameter ratio; and therefore a different wire tension, wouldbe achieved.

Another possibility isto insert a stepped. or stepless' gear between a winding drum and a wrapping wheel of constant diameter, the wire tension beingtnen controllable by means of the transmission gear ratio. A slipping clutch can additionally. be provided between thewind ing drum and'the wrapping wheel, so thata specific maximum tension of the wrapping wire is in no case exceeded.

Having. thus described the invention, what is claimed as new and" desired" to be secured by Letters Patent,-is:

l. A machinefor wrapping Wire and like tie: means about a-relatively rigid object, comprising drivemeans of said'object'to be wire-wrapped, winding means includ-' ing a frame carried by said shaft. and arranged for displacement with said shaft and in axial direction thereof,

a winch. mounted on said chassis. and. having a cable connecting said' chassis with said: framefor height adjusting the latter together with said shaft relative to said outer wall; surface while said top surface, to thereby facilitate placingrsaid wire around said object a predetermined pitch, said shaftcarrying, a winding drum for rotation therewith, a. wire wrapping sheave freely rotatable about the axis of. said shaftand operatively connected to said winding drum, guide means for said wrapping wire, said guide means including cable guide means looped around said outer wall surface of said object and around said winding drum, tensioning means for said cable guide means displaceable: relative to said drum. and carried by said frame and operatively engaging said cable guide means,,roller' meanson said. frame for. contact with' said outer Wall surface for spacingsaid framefrom the latter, and means displacing said tensionmg, means relative to-said drum, the ratio of'the diameter of saiddrum to that'of said sheave being so chosen asito ensure fora given period of: tiizoea'predetermined difference between the travel ofsaid drum.

sheave and said drum, said diameter ratio varying'means Upon approach of these chassis rotates on said its untensioned state; wound about masses including adjustable means disposed on said shaft and shiftahle in the longitudinal direction of said shaft.

3. A machine according to claim 2, said adjustable means comprising a sheave portion displaceable along said shaft relative to the remainder of said sheave, and means operating on said sheave portion for displacing the same along said shaft to thereby vary the diameter of said sheave.

4. A machine according to claim 1, said sheave comprising two portions, one displaceable relative to the other along said shaft, said portions being provided with com plementary peripheral flanges for engaging said wrapping wire therebetween, whereby the effective diameter of said sheave may be changed by relative displacement of said portions to thereby vary the diameter ratio between said drum and said sheave.

5. A machine according to claim 4, wherein said flanges converge toward each other and toward the axial center of said sheave.

6. A machine for wrapping reinforcing wire about a relatively rigid object, comprising drive means arranged on the top surface of said object and rotatable thereon about the center of said object, said drive means including a motor, motion transmission means in driven relation with said motor, a shaft in operative connection with said transmission means for rotation therewith and for axial displacement relative thereto and arranged a predetermined distance from the outer wall surface of said object to be wire-wrapped, winding means including a frame carried by said shaft and arranged for displacement with and in axial direction of said shaft relative to said outer wall surface, a cable connected with said drive means and said frame for height-adjusting the latter together with said shaft relative to said outer wall surface while said winding means is rotated by said drive means about said outer wall surface, to thereby facilitate placing said Wire around said object at predetermined pitch, said frame of said winding means enclosing a winding drum fixed to said shaft and rotatable therewith, a wire wrapping sheave freely rotatable about the axis of said shaft and operatively connected to said Winding drum, guide means for said winding means and including cable guide means looped around said outer Wall surface of said object and around said winding drum, tensioning means for said cable guide means carried by said frame and displaceable relative to said drum and opera.- tively engaging said cable guide means, roller means on said frame for contact with said outer wall surface for spacing said frame from the latter, and rack and gear means for displacing said tensioning means relative to said drum, the ratio of the diameter of said drum to that of said sheave being so chosen as to ensure for a given period of time a predetermined difference between the travel of said drum with said frame around said object and the length of wire as measured in its untensioned state wound about said object as said sheave travels about the latter with said frame, whereby said wire will be applied to said object under predetermined tension.

7. A machine for wrapping wire about a relatively rigid object, comprising drive means including a wheeled chassis arranged on the top surface of said object and rotatable thereon about the center of said object, a motor mounted on said chassis, motion transmission means in driven relation with said motor and carried by said chassis, a shaft in operative connection with said transmission means for rotation therewith and for axial displacement relative thereto and arranged a predetermined distance beyond the outer wall surface of said object to be wire-wrapped, winding means including a frame carried by said shaft and arranged for linear movement with said shaft upon axial displacement of the latter, a winch mounted on said chassis and having a cable connecting said chassis with said frame for heightadjusting the latter with said shaft relative to said outer wall surface while said chassis rotates on said top surface, to thereby facilitate placing said wire around said object at predetermined pitch, said frame including a winding drum mounted on said shaft for rotation therewith, a wire wrapping sheave freely rotatable about the axis of said shaft and operatively connected to said winding drum, cable guide means looped around said outer wall surface of said object and around said winding drum, tensioning means for said cable guide means displaceable relative to said drum and operatively connected to said cable guide means, roller means on said frame for contact with said outer wall surface for spacing said frame from the latter, and means controlling said tensioning means relative to said drum, the ratio of the diameter of said drum to that of said sheave being so chosen as to ensure for a given period of time a pre determined difference between the travel of said drum with said frame around said object and the length of wire as measured in its untensioned state wound about said object as said sheave travels about the latter with said frame, whereby said wire is wrapped around said object with predetermined tension.

References Cited in the file of this patent UNITED STATES PATENTS 1,180,232 Brown Apr. 18, 1916 1,249,809 Noble Dec. 11, 1917 2,184,744 Jonassen Dec. 26, 1939 2,372,060 Crom Mar. 20, 1945 2,520,403 Hirsh Aug. 29, 1950 2,573,793 Kennison Nov. 6, 1951