CA1180167A - Apparatus for stripping the jacket from cast concrete - Google Patents

Abstract

ABSTRACT
Apparatus for stripping the form jacket from a section of case concrete pipe in which an upward force is exerted on the jacket to strip it axially upwardly from a section of pipe standing on the floor or the like while simultaneously exerting a downward force against the pipe via a header ring at its upper end. The mechanism for exerting the downward force preferably includes an air cylinder acting between the upper header ring and a transverse beam that is connected to the jacket and lifted by an overhead hoist, for example.

Description

The invention relates to the manufacture o~ concrete pipes of relatively large size such as those used in resi-dential and commercial sewer and like drainage systems, culverts, and the like and more particularly to that phase of such manufacture that pertains to stripping the mold jacket from the lengths of pipe after casting. So far as is known at present, the prior art has relied upon an overhead hoist or the like for lifting the jacket straight upwardly from the standing pipe, depending upon the sheer weight of the pipe to keep the pipe in place.
According to the present invention, there is provided apparatus in which the lifting force on the jacket is aug-mented by a downward and positive or active force on the pipe. This is achieved by the use of a force-exorting device, preferably power-operated, interposed between the jacket-lifting means and the header at the top end of the pipe so that as the jacket is moved upwardly relative to the pipe, the pipe is moved oppositely relative to the jacket. A
pneumatic device has been found to be ideal for the purposes here intended. The invention further features removable and replaceable force-transmitting elements for use between the power device and the pipe so as to accommodate pipes of dif-ferent sizes, and in one form of the invention, a common force-transmitting element may be used that is adjustable. In order to best accommodate pipes of diameters varying between, say, twelve and seventy-two inches, it is preferable to provide the adjustable elements in ~wo or more ranges, say eighteen to thirty-six inches and thirty to sixty-six inches. It is also contemplated to provide assist means in the form of hydraulic cylinders for exerting additional force on the beam that lifts the jacket,it being further contemplated that such cylinders may be used with or without the beam and with or without the power device.

- 2 -In the Drawings:
Fig. 1 is an elevation, partly in section, showing an initial stage in the stripping operation.
Fig. 2 is a similar view but showing the stripping under way.
Fig. 3 is a partial view showing more of the hoist and air system than appears in Figs. 1 and 2 but omitting the cable and spring system.
Fig. 4 is an enlarged sectional view showing a wear~ap strip means within the ~acket.
Fig. 5 is an elevation, enlarged over the scale of Figs.
1 and 2, and showing auxiliary external means as used to lift the jacket and pipe from a floor-supported core.
Fig. 6 is a view similar to Fig. 5 but showing the auxil-iary means as used in the stripping system of Figs. 1 and 2.
Fig. 7 is a plan, with a portion broken away to show the interior, of an adjustable force-transmitting element used in the stripping system.
Fig. 8 is a fragmentary elevation of one of the adjustable arms used in the structure of Fig. 7.
Fig. 9 is a plan view, with a portion broken away, of the unit that attaches to the bottom of the air cylinder or bag.
Fig. 10 is a section as seen along the line 10-10 of Fig. 9.

~Q~7 Reference will be Eirst had to Figs. 1 and 2 for a brief review of the basics of one form of concrete pipe manufacture, considerably simplified and abbreviated in order to concen-trate on the present invention. Typically, a floor or suppor-t 10 is chosen on which the mold of form 12 is carried. For present purposes, it will be assumed that the form is essen-tially cylindrical for the manufacture of concrete pipe. One known form comprises an inner, cylindrical core, not shown in Figs. 1 and 2, an outer cylindrical jacket 14, an annular base member or ring 16 and an upper annular header or ring 18. The jacket is, of course, concentric with the core and provides an annular space 20 into which flowable concrete is introduced ~rom above to form ultimately a length of case concrete pipe 22. The concrete is introduced before the upper head is in-stalled, after which the header is set in place and held downand the form may be vibrated to settle the concrete. During this phase of the process, the jacket is locked to the lower ring 16 by any suitable releasable means 24.. The means for ap-plying downward force to the form is not shown, because in the stage of operating with which the instant invention is concern-ed, the form--i.e., the jacket, pipe and upper and lower rings--has been removed from the core. The present invention, so far as concerns Figs. l through 4 is primarily concerned with stripping the jacket upwardly from the settled pipe 22 while it rests on its lower ring 16. Fig. 2 shows the beginning of the stripping step.
In a modern pipe casting plant, pipe sections will be formed on apparatus including provision for handling, say, three pipe sections at once, although performing different operations on each. For the stripping stage, it will be assumed that the pipe and that much of the form appearing in Figs. 1 and 2 has either been brought to stripping means 26 or the means has been brought to the form.
As best seen in Fig. 3, this means may include suitable overhead support structure of steel beams or the like, as at 28 on which is carried a hoist 30 of known type, powered, for example, by electricity. This hoist has a typical depending cable or sheave system 32 having a hook 34. When the stripping ~3L80~

stage is initiated, the hoist is maneuvered so that the hook is centered over the pipe and form below i-t. Another part of this means is a beam means 36 which is disposed transversely across the form and, of course, above the header 18. This beam is connected at its midportion at 38 to the hoist hook 34. The jacket has rigidly attached thereto at diametrically opposite sides a pair of lift ears 40 and these are connected by lift chains or the like 42 to points on the beam quidistant from the midpoint of the beam. Since pipes of several diameters can be handled, it is contemplated that lift beams of various lengths will be provided and also that each range of beams will include selectively spaced points of attachment for the lift chains.
As will be seen from the description so far, were the lower lock means 24 released and the jacket lifted by the hoist and beam 36 without more, it is likely that the pipe would mo~e at least partly upwardly with the jacket and then drop, perhaps causing damage. To avoid this, the invention provides power-operated means in the form of a force-exerting device 44, here a fluid (air)-operated means comprising upper and lower plate members 46 and 48, respectively, and an inflatable and deflat-able air bag 50 sealed at opposite ends to the members 46 and 48. The upper member 46 is secured to the underside of the cross beam 36 in any suitable manner not material here and the lower member 48 operates against a force-applying element 52 that acts against the upper header. The two members 46 and 48 are interconnected to function as a unit, as will be described below (Figs. 9 and 10). The hoist is controlled in any suitable manner, not material here and is preferably electrically operat-ed, a motor being indicated at 54. The air bag is inflated bymeans of air under pressure supplied by an electrically powered motor 56 via a line 58 carried on a hose reel 60 (Fig. 3). The details in this area are not illustrated, since they are not themselves part of the invention and are known to those skilled in the art. The air bag is returned to deflated position by means of a multiple cable and spring system 62 (Figs. 1 and 2;
omitted from Fib. 3). The cables are preferably attached to the lower plate member 48 in any suitable manner, the connections shown in Fig. 10 being representative wherein it is shown that each cable passes un~er a welded-in member ~4 and is anchored to the unit 46-48 in any suitable manner, not shown.
These plates 46 and 48 are interconnected by weldments as at 66.
Reference will now be had to Figs. 9 and 10 for further details of the unit 46~48, the upper plate member of which is suitably adhered to the bottom of -the air bag. ~s best seen lQ in Fig. 9, a radial guide means 68 carries a slide 70 which has a depending s~ud 72 formed with a lower prong or hook 74.
A short vertical tubular member 76 partly encloses the pro-jecting lower end of the stud and is closed at its bottom by a ch~nfered closure 78, the function of which will appear later.
The slide is shiftable radially by means of a handle 80, shown in the drawing in retracted or unlocked position but operative to lock the slide in its inward position by means of a lock pin 82 engageable with a pair of alined holes 84 when the lock pin is pushed inwardly. When the lock is engaged in its inward position, the hook 74 is extended as in Fig. 10. When the slide i5 retracted, the hook recedes within the tubular member 76.
The purpose of the unit 46-48 and its hooked stud is to ena~le the attachment thereto of a further force-transmitting element 86 that intervenes between the unit 46-48 and the upper header or ring 18. The location of the element is shown in Figs~ 1 and 2 and the details appear in Figs. 7 and 8.
Essentially, this element has a plurality of generally radial arms 88, here three in number, each of which is pivoted at its inner end on a vertical axis at 90 to a pair of verti-cally spaced apart plates 92. The pivots are in the form ofupright tubes or spacers which, when combined with welded-in ribs 94, integrate the element parts; i.e., the plates and ribs are rigid and the arms are free to swing about their respective pivots. Fig. 9 shows the arms in maximum extended positions, say, for a pipe of six-feet in diameter. That is to say, the arms will span a header ring for a pipe of this diameter, and each arm has a depending pad 96 for engaging the header ring from above. In order that the arms will swing in unison and attain the same selected "reach" or span, the pivots 90 are respectively equipped with sheaves or sprockets 98 and a chain 100 is trained thereabout.
It will be seen that, when the arms are swung inwardly, their span decreases so that the element may be used on headers of smaller diameters. For retaining each increment of adjustment, each arm has a plurality of holes 102 which are selectively alined with holes 104 in the top plate 92 and suitable pins (not shown) dropped therethrough. Only a number of holes of each character is shown, it being clear that as many sets of holes may be provided as needed for the sizes of header rings to be employed.
The unit element 86 is detachably secured to the unit 46-48 by the hooked stud 72. The element 86 has a central opening 106 for this purpose; that is, for receiving the tube~enclosed stud in the initial assembly of the units, which is accomplished, of course, while the unit 46-48 is attached to the air bag and the element 86 is resting on the header ring via its pads. The element arms 88 will first have been adjusted to fi-t the particular header ring (an inwardly folded position of an arm 88 is shown in broken lines in Fig. 7).
The stud is retraced within the tube 76 and the air bag lower-ed until the tube-guided stud enters the hole 106, a task made easier by the chamfer at 78, after which the slide is pushed inwardly and locked, the hook 74 then engaging secure-ly under the lower plate 92 so that, when raised, the element 86 does not drop off of the unit 46-48.
Fig. 5 shows a different form of jacket 108 within which is disposed the usual core 110, the core in this instance not having been separated from the jacket and pipe or vice versa.
A lower member 112, floor-supported or otherwise fixed~ is provided at the base of the jacket and serves as a base from which a pair of fluid-operated motors or cylinder-piston units 114 can exert upward pressure against an upper beam 116 which is connected to a hoist hook 118 and which has at its opposite ends lift chains 120 connected to diametrically opposed points on the jacket. The upper beam is formed at opposite ends on its under side with downwardly openiny sockets 122 for receiving the upper ends of the piston rods of the motors 114. The purpose of the motors 114 in this form of the invention is to augment the upwar~ force exerted by the hoist-lifted upper beam, especially in a case in which the jacket and pipe are being stripped from a core.
Fig. 6 shows the use of the motors 114 and upper beam 116 with a system emplo~ing the down-pressure effects of an air bag as in Figs. 1 and 2. The air bag may exert down pressure either on a core, as used in Fig. 5, or on an ele-ment such as that disclosed at 86 previously.
Fig. 4 shows that the upper end of the jacket is supple-mented by wha~ is known as a wear/gap strip, a hardened steel band that fits within and is secured to the interior of the jacket wall. This member serves two purposes. First, it guards against premature wear of the upper part of the jacket and thus increases the life of the jacket. More importantly, it plays a significant part in enabling removal of the jacket without the exertion of an undue upward force on the header ring. That is to say, particles of the concrete mix find their way into any gap that would exist between the outer periphery of the header and the interior of the jacket wall.
In the present case, such gap is shown at 126 but the gap is between the header and the wear/gap strip or member. The vertical dimension of the strip is such that its lower edge is at least at the horizontal plane of the lower part of ~he header ring. Particles of the mix tending to work their way upwardly are stopped by the abutment effect of the lower edge of the strip, thus at least minimizing upward migration of these particles. The strip may be secured within the jacke~ by welding.
The instant disclosure has been based on preferred em~
bodiments and does not exclude modifications, alterations and equivalent structures.

Claims (14)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. Apparatus for stripping the jacket lengthwise from a length of concrete pipe previously cast in the jacket, comprising support means for supporting the jacket-contained pipe upright and at its lower end, an annular header resting on the upper end of the pipe, beam means spaced above and disposed transversely across the header, lift means spaced apart trans-versely of the pipe and operatively connected between the beam means and the jacket in such manner as to leave the head-er exposed, means for raising the beam means so as to exert a lifting force on the jacket relative to the pipe, and force-exerting means operative between the beam means and the header for exerting a downward force on the header and pipe as the jacket moves upwardly with the beam means.

2. The apparatus of Claim 1, in which the force-exerting means includes an expansible and contractible device.

3. The apparatus of Claim 2, in which said device is fluid operated.

4. The apparatus of Claim 1, including additional means operative between the support means and the jacket for exerting an additional raising force on the beam means.

5. The apparatus of Claim 1, in which the raising means includes an overhead lift device.

6. The apparatus of Claim 1, in which the force-exerting means includes a lower force-applying part normally spaced above the header and a force-transmitting element interposed between said part and the header for transmitting downward force from the power device via said part to the header.

7. The apparatus of Claim 6, including releasably means normally interconnecting the part and element for movement together.

8. The apparatus of Claim 7, in which said element is adjustable in at least one dimension transversely of the pipe and header so as to accommodate pipes and headers of other transverse dimensions.

9. The apparatus of Claim 8, in which said element in-cludes a center member and a plurality of legs radiating from said member, said legs being adjustable relative to the center member and to each other so as to achieve said adjust-ability.

10. The apparatus of Claim 9, including means intercon-necting the legs for movement and adjustability in unison.

11. The apparatus of Claim 8, in which said element in-cludes a center member, a plurality of pivot shafts journalled in the center member and spaced equi-angularly apart, a plu-rality of leg means, equal in number to the shafts, one leg being affixed to each shaft, and means for rotating the shafts in unison to project and retract the legs away from and back to the center member.

12. The apparatus of Claim 11, in which said last named means includes a plurality of sprockets, one affixed to each shaft and an endless chain trained about the sprockets.

13. The apparatus of Claim 1, including an annular band secured to and running continuously about the interior wall of an upper portion of the jacket and intervening annularly between the interior wall of the jacket and the outer periphery of the header.

14. The apparatus of Claim 13, in which the vertical di-mension of the annular member is such that its lower marginal edge is about in the horizontal plane of the bottom of the header.