CA2043773A1 - Variable top curb mold - Google Patents
Variable top curb moldInfo
- Publication number
- CA2043773A1 CA2043773A1 CA 2043773 CA2043773A CA2043773A1 CA 2043773 A1 CA2043773 A1 CA 2043773A1 CA 2043773 CA2043773 CA 2043773 CA 2043773 A CA2043773 A CA 2043773A CA 2043773 A1 CA2043773 A1 CA 2043773A1
- Authority
- CA
- Canada
- Prior art keywords
- curb
- mold
- concrete
- top plate
- height
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
- E01C19/00—Machines, tools or auxiliary devices for preparing or distributing paving materials, for working the placed materials, or for forming, consolidating, or finishing the paving
- E01C19/004—Devices for guiding or controlling the machines along a predetermined path
- E01C19/008—Devices for guiding or controlling the machines along a predetermined path by reference lines placed along the road, e.g. wires co-operating with feeler elements
-
- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
- E01C19/00—Machines, tools or auxiliary devices for preparing or distributing paving materials, for working the placed materials, or for forming, consolidating, or finishing the paving
- E01C19/48—Machines, tools or auxiliary devices for preparing or distributing paving materials, for working the placed materials, or for forming, consolidating, or finishing the paving for laying-down the materials and consolidating them, or finishing the surface, e.g. slip forms therefor, forming kerbs or gutters in a continuous operation in situ
- E01C19/4886—Machines, tools or auxiliary devices for preparing or distributing paving materials, for working the placed materials, or for forming, consolidating, or finishing the paving for laying-down the materials and consolidating them, or finishing the surface, e.g. slip forms therefor, forming kerbs or gutters in a continuous operation in situ for forming in a continuous operation kerbs, gutters, berms, safety kerbs, median barriers or like structures in situ, e.g. by slip-forming, by extrusion
Landscapes
- Engineering & Computer Science (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Road Paving Machines (AREA)
- Moulds For Moulding Plastics Or The Like (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A Method and apparatus for continuously forming concrete curbs is disclosed, in which the elevation of the top surface of the curb may be varied independently of the lower portion of the curb. A curb mold according to the invention employs a top plate to shape the top surface of the curb being formed within the mould. Positioning means, such as a hydraulic cylinder, mounted on the curb mold, may be used to controllably adjust the vertical position of the top plate relative to the curb mold so as to adjust the height of the finished curb. The design of the top plate ensures that an acceptable surface finish is obtained, regardless of the position of the top plate, so that manual refinishing of the curb, after the curb has been formed in the mold, is not required.
A Method and apparatus for continuously forming concrete curbs is disclosed, in which the elevation of the top surface of the curb may be varied independently of the lower portion of the curb. A curb mold according to the invention employs a top plate to shape the top surface of the curb being formed within the mould. Positioning means, such as a hydraulic cylinder, mounted on the curb mold, may be used to controllably adjust the vertical position of the top plate relative to the curb mold so as to adjust the height of the finished curb. The design of the top plate ensures that an acceptable surface finish is obtained, regardless of the position of the top plate, so that manual refinishing of the curb, after the curb has been formed in the mold, is not required.
Description
/ 3 i`~
The present invention relate~ to a method and apparatus for forming continuous concrete structures, and in particular a method and apparatus for continuously forming a concrete curb.
Various apparatus are k:nown in the art for forming continuous concrete curbs. In general, an open-ended curb mold is used to define the cross-sectional shape o~ the curb.
The interior surfaces of the curb mold are adapted to ensure that the concrete curb formed therein has an acceptable surface finish when it leaves the open end of the mold. This eliminates the necessity for finishing the curb by hand, after it has been formed by the mold. A hopper generally encloses the front end of the curb mold, and directs concrete into tha curb mold. The hopper may also comprise vibrators, or other means for compacting the concrete in the mold, and for removing entrained air. This stiffens the plastic (i.e.
uncured) concrete so that it will retain the shape of the curb mold, after the concrete has passed out of the open end of the curb mold, until the concrete has cured.
The curb mold may be mounted on a machine adapted for this purpose, such as, for example a Gomaco GT3300. This machine comprises means for moving the mold at a controlled speed along the dPsired path of the finished curb~ Typically, a sensor system, for example a grade wire and probe, is used to vary the vertical position of the curb mold with respect to the ground, so as to ensure that the curb follows a predefined grade.
By this means, it is generally possible to economically construct any desired length of continuous concrete curb, with a finished desired grade, and an acceptable surface finish.
Typically, curb molds are constructed so that a variety of cross-sectional shapes may be formed. One curb mold is constructed for each different shape. one of the most common shapes is a simple rectangular, or wall-like curb.
Another common curb shape includes a built~in gutter. The 2~ J~7 ' gutter curb is a variation of the simple rectangular curb.
In this case, a low step-like rectangular section is formed integral with the base of the curb, on the side of the curb facing the roadway. The top of the gutter portion of the curb is maintained at or slightly below the finished road surface elevation, typically using automat:ic control means such as the above-mentioned grade wire and probe.
The conventional curb molds, as described above, have proven to be an efficient means of forming concrete curbs. However, their design is optimised to produce concrete curb with a constant cross-section shape. When the mold is used to build a curb past a lane-way, for example, the formed curb must be modified by lowering the top of the curb down to approximately the level o~ the finished road surface. In the case of a simple rectangular curb, this can be accomplished simply by lowering the curb mold by the required amount.
However, If the curb is constructed with a built-in gutter, this approach is not possible, because the gutter must remain at the level of the finished road surface.
A variety of solutions to this problem have been proposed. The simplest is to form the curb using the curb mold in the normal manner, and then manually cut away the excess concrete as required ti.e. in the vicinity of the lane-way). The surface of the reshaped curb is then refinished by hand to achieve an acceptable surface finish. This solution is labour-intensive, slow, and tends to produce a significant amount of waste, particularly in areas characterised by many lane-ways, such as housing developments.
In order to reduce the amount of labour and waste concrete, it has been proposed to modify the curb mold by adding a substantially vertical baffle which may be inserted into the mold so as to block off the upper portion of the mold. By this means, the upper portion of the curb may be selectively "cut-off" in the vicinity of a lane-way. While this method reduces the amount of wasted concrete, the resulting curb must be finished by hand in order to achieve an acceptable surface finish.
2 ~3 ~ ~3, 7 ~ ~
It is th~refore an object of the present invention to provide an apparatus for forming continuous concrete curb, wherein the apparatus is adapted so that the top of the finished curb can be varied, independently of the gutter or lower portion of the curb, during the forming process.
According to one aspect of the invention, there is provided an apparatus for forming continuous concrete curbs, which apparatus comprises: an open ended mold section defining the largest cross-sectional shaple of the finished curb; a hopper generally enclosing the front end of said mold section for directing the flow of plastic concrete into the mold; and height adjusting means adapted for controllably adjusting the height of the finished curb with respect to the lower portion of said curb.
According to another aspect of the invention, there is provided a curb forming machine for forming continuous concrete curbs, which machine comprises: an open ended mold section defining the largest cross-sectional shape of the finished curb; a hopper generally enclosing the front end of said mold section for dirscting the flow of plastic concrete into the mold; and height adjusting means adapted for controllably adjusting the height of the finished curb with respect to the lower portion of said curb, wherein said height adjusting means comprises: a top plate for shaping the top surface of the curb; positioning means ~or adjusting the vertical position of said top plate with respect to said mold section; and control means for controlling said positioning means.
The mold section may be formed to produce any desired cross-sectional shape of the finished curb, within the limitations of thP workability of the concrete being used.
For example, a curb with a built-in gutter portion. The mold section defines tha largest shape o~ the curb, which may be used, for example, away from any lane-ways etc.
2~3~7~-~3 The hopper may comprise vibrators or other means for compacting the concrete into the mold so as to stiffen the concrete beEore it leaves the open end of the mold.
The height adjusting means generally comprises a mold top plate, which is adapted to shape the top surface of the finished concrete curb; a baffle attached to the forward edge of the mold surface, to block off the portion of the mold above the top plate and thus prevent concrete from passing around the top plate; guide means for smoothly guiding the top plate and baffle as they are alternately extended into and withdrawn from, the mold section; and means for extending and withdrawing the top plate and the baffle into (and out of) the mold section so as to effectively lower and raise the top of the mold with respect to the lower or gutter portions of the finished curb. The top plate is further adapted to ensure that an acceptable surface finish of the curb is obtained irrespective of the vertical position o~ the top plate.
The height adjusting means may be either manually of automatically controlled. For example, automatic control may be effected by use of a grade wire and probe. In this case, a first grade wire and probe may be used to control the elevation of the cur~ mold as a whole. Thus the gutter portion is maintained at the height of the finished road surface. A ~econd grade wire and probe is then used to control the elevation of the upper surface of the finished curb, independently of the gutter portion~
The curb mold according to the invention may be carried by an essentially conventional curb forming machine, which has been suitably adapted for this purpose. As will be explained in greater detail, the required modifications, even for automatic control, are relatively simple and employ readily available equipment. The invention can therefore be implement~d as a comparatively inexpensive retrofit for existing curb forming machines and molds.
According to another aspect the invention there is provided a method of continuously forming a concrete curb, which method comprises the steps of: maintaining a cu~b mold 2~ J7 i~
at a predetermined elevation with respect to the finished grade of an adjacent road surface; supplying plastic concrete to said mold, and compacting it therein 50 as to form the curb; and controllably varying the vertical position of an upper portion of said curb mo:Ld, with respect to said predetermined elevation, so as to selectively vary the height of said curb.
The preferred embodiments of the invention are lo described, with reference to the appended drawings, in which:
Figure 1 is a perspective view of a conventional curb mold o~ the built-in gutter type, and a section of curb formed thereby;
Figure 2 is a perspective view of a curb mold of the built-in gutter type according to the invention, and a section of curb formed thereby;
Figure 3 is another perspective view of the curb mold illustrated in Figure 2, and a section of curb formed thereby; and Figure 4 illustrates the use of two grade wires as employed by the invention;
It will be noted that the above noted figures, and the embodiments described herein refer to curbs of the built-in gutter type. However, it will be understood that this is by way of example only, and is not limitative o~ the invention. It will be further noted that throughout the figures, like features are referenced by like numerals.
Referring now ko Figure l~ A conventional curb mold 2 generally comprises a mold section 4l and a hopper 6 into which plastic (uncured) concrete is placed. VibratGrs or other compacting means (not shown) are employed to compact the concrete into the mold section 4. As the curb mold advances forward, the formed curb 3 emerges from the open rear of the mold section 4. The vibrators or other compacting means ensure that the plastic concrete has sufficient ~ ~3 ~ ~ ) 7 `~
stiffness to resist slumping of the curb 3 before the concrete has set and cured. The curb mold 2 is carri~d in close proximity to the ground by a conventional curb molding machine (not shown~ which maintains the curb mold 2 at a predetermined elevation. For example, the curb molding machine typically employs hydraulic actuators, controlled by a grade wire and probe, to automatically adjust the height of the mold so that the elevation of the gutter portion 5 approximately corresponds with the finished height of the road ~urface. It will be understood that the use of a grade wire and probe, in this application, is well understood by those skilled in the art, and therefore further detailed illustration and/or description thereof is unnecessary.
It can be seen from Figure 1 that the mold section 4 is of a fixed geometry. Thus the height of the curb 3 is determined by the shape of the mold section 4, and the requirement that the gutter elevation conform to the roadway.
Thus in particular areas, or example in the vicinity of a lane-way, at least a portion of the formed curb 3 must be cut away, and the surface refinished, in order to lower to top of the curb 3 by the required amount to permit passage of vehicles or the like.
Figures 2 and 3 illustrate a curb mold accordiny to the present invention. Like the conventional curb mold illustrated in Figure 1, the curb mold of the invention is carried in close proximity to the ground by a curb molding machine ~not shown). The curb molding machine of the invention is essentially a conventional curb molding machine which has been adapted to permit either manual or automatic control of the height adjusting means, and will be described in more detail later.
~ curb mold according to the invention comprises a mold section 4, a hopper 6 and a height adjusting means, referred to ganerally by reference numeral 8. The height adjusting means 8 comprises a movable top plate 10, which is shaped to conform to the upper surface of the mold section 4. By this means, when the top plate 10 i~ in its fully ~ ~ ~ 3 ~ 3 raised position (as seen in Figure 2), it forms a surface contiguous with the upper surface of the mold section 4. In this condition, the curb mold produces a curb 3 of a maximum height, in precisely the same manner as the conventional curb mold illustrated in Figure 1. Disposed at front end (i.e.
towards the hopper 6) of the top plate 10 is a baffle plate 12. Similarly, a keeper plate 13 is disposed at the rear of the top plate 10.
When the top plate lO is extended downwards into the upper portion of the mold section 4, the contour of the top plate 10 ensures that the upper surface of the formed curb retains an acceptable profile and surface finish. The baf~le plate 12 effectively closes off the portion of the mold section 4 that extends above the level of the top plate 10.
By this means, the use of concrete varies with the size of the cross-section of the curb being formed, and waste is reduced to a minimum. In addition, the baffle plate 12 and the keeper plate 13 are adapted to operatively slide in guides 14 provided on the outside of the mold for this purpose. Thus the baffle plate 12 and the keeper plate 13 act to maintain the top plate 10 in a correct alignment with respect to the mold section 4, and prevent the top plate 10 from being forced out of position by the pressure of the concrete in the hopper 6 and mold section 4. To further prevent displacement of the top surface 10 during operation, gusset plates or other bracing means (not shown) may be employed.
The vsrtical position of the top plate 10 is controlled by positioning means 16 (for example, a hydraulic actuator as illustrated in Figures 2 and 3) mounted between the top plate 10 and a suitable mounting fram (not shown)~
As can be se~n in Figure 2, when the top plate 10 is raised to its maximum height, the curb mold according to the invention functions in the same manner as the conventional curb mold. Howevex, when the positioning means 16 extends the top plate 10 downwards into the mold, as illustrated in Figure 3, the top plate 10 and baffle plate 12 cooperate so as to effectively reduce the height of the top of the curb 3 2~:3r~7 r~
relative to the gutter portion 5. Thus by selectively lowering and raising the top plate 10, the finished height of the curb 3 can be varied as required, for example in the vicinity of lane-ways. Furthermore, the contour of the top plate 10 ensures that the formed curb 3 will have an acceptable surface finish, regardless of the height of the curb 3, without the need Eor manual refinishing.
As mentioned previously, the vertical position of tha top plate 10 is adjusted by positioning means 16, such as a hydraulic cylinder, operatively mounted on a suitable support frame (not shown). When the curb mold of the invention is installed on a curb forming machine, means provided thereon may be used to either manually or automatically control the positioning means 16.
In the case of manual control, two methods may be employed.
The conventional curb forming machine, such as a Gomaco GT3300, comprises manually and/or automatically controlled hydraulic circuits to ad~ust such parameters as the height of the machine, the attitude (i.e. ~o keep the machine level), and the lateral (i.e. side-to-side) offset of the machine. Additional hydraulic circuits are used to propel the machine in forward and reverse directions, as well as to effect directional control.
Prior to starting to form a curb, the curb mold is attached to the curb forming machine, which is then moved into a position so that the curb mold is in close proximity to the starting point for the curb, and aligned parallel to the desired curb path. The curb mold is then levelled by levelling the curb forming machine, and adjusted laterally~
using the lateral offset controls of the curb forming machine, so that it is located vertically over the correct position for starting the curb. Finally, th~ curb mold is lowered to the correct elevation by lowering the curb forming machine until a sensor probe attached thereto engages a grade wire which has ~.
been previously set out along the path of the curb. The grade 9 2 ~ ~ ~ 1 7 ~
wire is supported on poles or stakes placed at intervals beside the desired path of the curb, and is set such that it accurately defines the elevation of the curb. As the curb forming machine forms the curb, the vertical height of the curb forming machine (and therefore the curb mold) is continuously adjusted in response to control inputs generated by the sensor probe and the grade wire, so ~hat the elevation of the finished curb conforms to the profile defined by the grade wire.
In practice, it has been found that the lateral offset circuit of the curb forming machine is used only during the initial set-up prior ko starting the curb forming run.
Thereafter, the lateral adjustment of the curb is performed by effecting steering corrections to the direction of travel of the machine.
Thus in a first embodiment of the invention, the positioning means 16 may be manually controlled using the ~! ~; t I lateral offset hydraulic circuit. In this case, the curb mold and curb forming machine are set up and adjusted, prior to 2U beginning a curb forming run, in the usual manner. However, immediately prior to starting the run, the hydraulic lines of the lateral offset circuit are disconnected from the lateral offset hydraulic actuator, and connected instead to the positioning means 16. The conventional hydraulic lines and couplers, whic~`-are already installed on the conventional curb forming machine are ideal for this purpose. The conventional couplers include a valve means which substantially prevents leakage of significant q~lantities o~
hydraulic fluid. Thus when the hydraulic lines are disconnected from the lateral offset hydraulic actuator, the actuator is effectively locked in position. Under these conditions, the curb forming operation may proceed in the conventional manner until ~uch times as the curb forming machine arrives at a location, such as near a lane-way, where the top of the curb 3 must be lowered. At this point in the operation, the operator of the curb forming machine uses the manual control for the lateral offset to extend the 2 ~ 7 r~ ~
positioning means 16, thereby lowering the top plate 10 into the mold section 4 and effecting the required lowerlng of the top of the curb 3. Similarly, the operator can raise the top of the curb 3 by retracting the positioning means 16, again using the lateral o~fset controls of the curb ~orming machine.
In a second embodiment of the invention, which also employs manual control ~or adjusting the positioning means 16, a separate hydraulic circuit is added to the conventional curb ¦ forming machine. This eliminates the need for disconnecting the lateral offset hydraulic circuit of the curb forming machine. In addition, a separate curb height adjustment circuit can be designed to provide the operator with a greater degree of control than is possible by using the lateral offset circuit and controls.
A third embodiment of the invention permits the height of the curb to be automatically controlled. It will be recalled that during a conventional curb forming operation, the vertical position of the curb mold is continuously adjusted by using a sensor probe and grade wire to control the vertical adjustment hydraulic circuit of the curb forming machine. Automatic control of the positioning means 16 may be performed in an analogous manner.
In this case, the sensor probe may be disposed on mounting means depending from the height adjusting means 8.
In this manner, the sensor probe moves vertically in direct relation to the top plate 10. A curb height grade wire, in addition to the grade wire described above, is used in conjunction with this second probe to supply control input signals to an automatic hydraulic circuit in a manner directly analogous to that used to adjust the vertical position of the curb forming machine itself. As may be seen ~rom Figure 4, in this embodiment, two grade wires are mounted on support posts 20 set out beside the desired path of the curb 26, which may be at least partially graded and prepared. A first grade wire 22 defines the elevation profile of the curb mold as a whole. Thus grade wire 22 is used to maintain the elevation of the gutter at a predetermined height with respect to the rl s?
ll finished surface of the roadway. A second grade wire 24 is then used to define the profile of the top of the curb, ~or example, as shown in Figure 4, defining a smooth transition between a general curb section and a lane-way.
It will be apparent to those skilled in the art that there are various ways in which the invention may be modified.
For example, the positioning means 16 could electrical instead of hydraulic. In this case, an electric motor and a drive screw might be used in conjunction with appropriate control means to effect the desired positioning of the top plate 10.
In another alternative~ the positioning means 16 might comprise more than one actuator. For example, two actuators, disposed at opposite ends of the top plate 10 could be employed. By this means the two actuators could be independently controlled (for example by using two probes travelling along the grade wire 24) so that the slope of the top plate 10 may be adjusted to more accurately follow the contour of the top of the curb 3, and thereby improve the surface finish, during height transitions.
~ urthermore, it will be seen that in the appended figures, the height adjusting means 8 comprises only a portion of the top of the mold section 4. However, it will be obvious that the height adjusting means 8 could be extended such that the top of the mold section 4 is almost entirely composed of the top platP 10.
The present invention relate~ to a method and apparatus for forming continuous concrete structures, and in particular a method and apparatus for continuously forming a concrete curb.
Various apparatus are k:nown in the art for forming continuous concrete curbs. In general, an open-ended curb mold is used to define the cross-sectional shape o~ the curb.
The interior surfaces of the curb mold are adapted to ensure that the concrete curb formed therein has an acceptable surface finish when it leaves the open end of the mold. This eliminates the necessity for finishing the curb by hand, after it has been formed by the mold. A hopper generally encloses the front end of the curb mold, and directs concrete into tha curb mold. The hopper may also comprise vibrators, or other means for compacting the concrete in the mold, and for removing entrained air. This stiffens the plastic (i.e.
uncured) concrete so that it will retain the shape of the curb mold, after the concrete has passed out of the open end of the curb mold, until the concrete has cured.
The curb mold may be mounted on a machine adapted for this purpose, such as, for example a Gomaco GT3300. This machine comprises means for moving the mold at a controlled speed along the dPsired path of the finished curb~ Typically, a sensor system, for example a grade wire and probe, is used to vary the vertical position of the curb mold with respect to the ground, so as to ensure that the curb follows a predefined grade.
By this means, it is generally possible to economically construct any desired length of continuous concrete curb, with a finished desired grade, and an acceptable surface finish.
Typically, curb molds are constructed so that a variety of cross-sectional shapes may be formed. One curb mold is constructed for each different shape. one of the most common shapes is a simple rectangular, or wall-like curb.
Another common curb shape includes a built~in gutter. The 2~ J~7 ' gutter curb is a variation of the simple rectangular curb.
In this case, a low step-like rectangular section is formed integral with the base of the curb, on the side of the curb facing the roadway. The top of the gutter portion of the curb is maintained at or slightly below the finished road surface elevation, typically using automat:ic control means such as the above-mentioned grade wire and probe.
The conventional curb molds, as described above, have proven to be an efficient means of forming concrete curbs. However, their design is optimised to produce concrete curb with a constant cross-section shape. When the mold is used to build a curb past a lane-way, for example, the formed curb must be modified by lowering the top of the curb down to approximately the level o~ the finished road surface. In the case of a simple rectangular curb, this can be accomplished simply by lowering the curb mold by the required amount.
However, If the curb is constructed with a built-in gutter, this approach is not possible, because the gutter must remain at the level of the finished road surface.
A variety of solutions to this problem have been proposed. The simplest is to form the curb using the curb mold in the normal manner, and then manually cut away the excess concrete as required ti.e. in the vicinity of the lane-way). The surface of the reshaped curb is then refinished by hand to achieve an acceptable surface finish. This solution is labour-intensive, slow, and tends to produce a significant amount of waste, particularly in areas characterised by many lane-ways, such as housing developments.
In order to reduce the amount of labour and waste concrete, it has been proposed to modify the curb mold by adding a substantially vertical baffle which may be inserted into the mold so as to block off the upper portion of the mold. By this means, the upper portion of the curb may be selectively "cut-off" in the vicinity of a lane-way. While this method reduces the amount of wasted concrete, the resulting curb must be finished by hand in order to achieve an acceptable surface finish.
2 ~3 ~ ~3, 7 ~ ~
It is th~refore an object of the present invention to provide an apparatus for forming continuous concrete curb, wherein the apparatus is adapted so that the top of the finished curb can be varied, independently of the gutter or lower portion of the curb, during the forming process.
According to one aspect of the invention, there is provided an apparatus for forming continuous concrete curbs, which apparatus comprises: an open ended mold section defining the largest cross-sectional shaple of the finished curb; a hopper generally enclosing the front end of said mold section for directing the flow of plastic concrete into the mold; and height adjusting means adapted for controllably adjusting the height of the finished curb with respect to the lower portion of said curb.
According to another aspect of the invention, there is provided a curb forming machine for forming continuous concrete curbs, which machine comprises: an open ended mold section defining the largest cross-sectional shape of the finished curb; a hopper generally enclosing the front end of said mold section for dirscting the flow of plastic concrete into the mold; and height adjusting means adapted for controllably adjusting the height of the finished curb with respect to the lower portion of said curb, wherein said height adjusting means comprises: a top plate for shaping the top surface of the curb; positioning means ~or adjusting the vertical position of said top plate with respect to said mold section; and control means for controlling said positioning means.
The mold section may be formed to produce any desired cross-sectional shape of the finished curb, within the limitations of thP workability of the concrete being used.
For example, a curb with a built-in gutter portion. The mold section defines tha largest shape o~ the curb, which may be used, for example, away from any lane-ways etc.
2~3~7~-~3 The hopper may comprise vibrators or other means for compacting the concrete into the mold so as to stiffen the concrete beEore it leaves the open end of the mold.
The height adjusting means generally comprises a mold top plate, which is adapted to shape the top surface of the finished concrete curb; a baffle attached to the forward edge of the mold surface, to block off the portion of the mold above the top plate and thus prevent concrete from passing around the top plate; guide means for smoothly guiding the top plate and baffle as they are alternately extended into and withdrawn from, the mold section; and means for extending and withdrawing the top plate and the baffle into (and out of) the mold section so as to effectively lower and raise the top of the mold with respect to the lower or gutter portions of the finished curb. The top plate is further adapted to ensure that an acceptable surface finish of the curb is obtained irrespective of the vertical position o~ the top plate.
The height adjusting means may be either manually of automatically controlled. For example, automatic control may be effected by use of a grade wire and probe. In this case, a first grade wire and probe may be used to control the elevation of the cur~ mold as a whole. Thus the gutter portion is maintained at the height of the finished road surface. A ~econd grade wire and probe is then used to control the elevation of the upper surface of the finished curb, independently of the gutter portion~
The curb mold according to the invention may be carried by an essentially conventional curb forming machine, which has been suitably adapted for this purpose. As will be explained in greater detail, the required modifications, even for automatic control, are relatively simple and employ readily available equipment. The invention can therefore be implement~d as a comparatively inexpensive retrofit for existing curb forming machines and molds.
According to another aspect the invention there is provided a method of continuously forming a concrete curb, which method comprises the steps of: maintaining a cu~b mold 2~ J7 i~
at a predetermined elevation with respect to the finished grade of an adjacent road surface; supplying plastic concrete to said mold, and compacting it therein 50 as to form the curb; and controllably varying the vertical position of an upper portion of said curb mo:Ld, with respect to said predetermined elevation, so as to selectively vary the height of said curb.
The preferred embodiments of the invention are lo described, with reference to the appended drawings, in which:
Figure 1 is a perspective view of a conventional curb mold o~ the built-in gutter type, and a section of curb formed thereby;
Figure 2 is a perspective view of a curb mold of the built-in gutter type according to the invention, and a section of curb formed thereby;
Figure 3 is another perspective view of the curb mold illustrated in Figure 2, and a section of curb formed thereby; and Figure 4 illustrates the use of two grade wires as employed by the invention;
It will be noted that the above noted figures, and the embodiments described herein refer to curbs of the built-in gutter type. However, it will be understood that this is by way of example only, and is not limitative o~ the invention. It will be further noted that throughout the figures, like features are referenced by like numerals.
Referring now ko Figure l~ A conventional curb mold 2 generally comprises a mold section 4l and a hopper 6 into which plastic (uncured) concrete is placed. VibratGrs or other compacting means (not shown) are employed to compact the concrete into the mold section 4. As the curb mold advances forward, the formed curb 3 emerges from the open rear of the mold section 4. The vibrators or other compacting means ensure that the plastic concrete has sufficient ~ ~3 ~ ~ ) 7 `~
stiffness to resist slumping of the curb 3 before the concrete has set and cured. The curb mold 2 is carri~d in close proximity to the ground by a conventional curb molding machine (not shown~ which maintains the curb mold 2 at a predetermined elevation. For example, the curb molding machine typically employs hydraulic actuators, controlled by a grade wire and probe, to automatically adjust the height of the mold so that the elevation of the gutter portion 5 approximately corresponds with the finished height of the road ~urface. It will be understood that the use of a grade wire and probe, in this application, is well understood by those skilled in the art, and therefore further detailed illustration and/or description thereof is unnecessary.
It can be seen from Figure 1 that the mold section 4 is of a fixed geometry. Thus the height of the curb 3 is determined by the shape of the mold section 4, and the requirement that the gutter elevation conform to the roadway.
Thus in particular areas, or example in the vicinity of a lane-way, at least a portion of the formed curb 3 must be cut away, and the surface refinished, in order to lower to top of the curb 3 by the required amount to permit passage of vehicles or the like.
Figures 2 and 3 illustrate a curb mold accordiny to the present invention. Like the conventional curb mold illustrated in Figure 1, the curb mold of the invention is carried in close proximity to the ground by a curb molding machine ~not shown). The curb molding machine of the invention is essentially a conventional curb molding machine which has been adapted to permit either manual or automatic control of the height adjusting means, and will be described in more detail later.
~ curb mold according to the invention comprises a mold section 4, a hopper 6 and a height adjusting means, referred to ganerally by reference numeral 8. The height adjusting means 8 comprises a movable top plate 10, which is shaped to conform to the upper surface of the mold section 4. By this means, when the top plate 10 i~ in its fully ~ ~ ~ 3 ~ 3 raised position (as seen in Figure 2), it forms a surface contiguous with the upper surface of the mold section 4. In this condition, the curb mold produces a curb 3 of a maximum height, in precisely the same manner as the conventional curb mold illustrated in Figure 1. Disposed at front end (i.e.
towards the hopper 6) of the top plate 10 is a baffle plate 12. Similarly, a keeper plate 13 is disposed at the rear of the top plate 10.
When the top plate lO is extended downwards into the upper portion of the mold section 4, the contour of the top plate 10 ensures that the upper surface of the formed curb retains an acceptable profile and surface finish. The baf~le plate 12 effectively closes off the portion of the mold section 4 that extends above the level of the top plate 10.
By this means, the use of concrete varies with the size of the cross-section of the curb being formed, and waste is reduced to a minimum. In addition, the baffle plate 12 and the keeper plate 13 are adapted to operatively slide in guides 14 provided on the outside of the mold for this purpose. Thus the baffle plate 12 and the keeper plate 13 act to maintain the top plate 10 in a correct alignment with respect to the mold section 4, and prevent the top plate 10 from being forced out of position by the pressure of the concrete in the hopper 6 and mold section 4. To further prevent displacement of the top surface 10 during operation, gusset plates or other bracing means (not shown) may be employed.
The vsrtical position of the top plate 10 is controlled by positioning means 16 (for example, a hydraulic actuator as illustrated in Figures 2 and 3) mounted between the top plate 10 and a suitable mounting fram (not shown)~
As can be se~n in Figure 2, when the top plate 10 is raised to its maximum height, the curb mold according to the invention functions in the same manner as the conventional curb mold. Howevex, when the positioning means 16 extends the top plate 10 downwards into the mold, as illustrated in Figure 3, the top plate 10 and baffle plate 12 cooperate so as to effectively reduce the height of the top of the curb 3 2~:3r~7 r~
relative to the gutter portion 5. Thus by selectively lowering and raising the top plate 10, the finished height of the curb 3 can be varied as required, for example in the vicinity of lane-ways. Furthermore, the contour of the top plate 10 ensures that the formed curb 3 will have an acceptable surface finish, regardless of the height of the curb 3, without the need Eor manual refinishing.
As mentioned previously, the vertical position of tha top plate 10 is adjusted by positioning means 16, such as a hydraulic cylinder, operatively mounted on a suitable support frame (not shown). When the curb mold of the invention is installed on a curb forming machine, means provided thereon may be used to either manually or automatically control the positioning means 16.
In the case of manual control, two methods may be employed.
The conventional curb forming machine, such as a Gomaco GT3300, comprises manually and/or automatically controlled hydraulic circuits to ad~ust such parameters as the height of the machine, the attitude (i.e. ~o keep the machine level), and the lateral (i.e. side-to-side) offset of the machine. Additional hydraulic circuits are used to propel the machine in forward and reverse directions, as well as to effect directional control.
Prior to starting to form a curb, the curb mold is attached to the curb forming machine, which is then moved into a position so that the curb mold is in close proximity to the starting point for the curb, and aligned parallel to the desired curb path. The curb mold is then levelled by levelling the curb forming machine, and adjusted laterally~
using the lateral offset controls of the curb forming machine, so that it is located vertically over the correct position for starting the curb. Finally, th~ curb mold is lowered to the correct elevation by lowering the curb forming machine until a sensor probe attached thereto engages a grade wire which has ~.
been previously set out along the path of the curb. The grade 9 2 ~ ~ ~ 1 7 ~
wire is supported on poles or stakes placed at intervals beside the desired path of the curb, and is set such that it accurately defines the elevation of the curb. As the curb forming machine forms the curb, the vertical height of the curb forming machine (and therefore the curb mold) is continuously adjusted in response to control inputs generated by the sensor probe and the grade wire, so ~hat the elevation of the finished curb conforms to the profile defined by the grade wire.
In practice, it has been found that the lateral offset circuit of the curb forming machine is used only during the initial set-up prior ko starting the curb forming run.
Thereafter, the lateral adjustment of the curb is performed by effecting steering corrections to the direction of travel of the machine.
Thus in a first embodiment of the invention, the positioning means 16 may be manually controlled using the ~! ~; t I lateral offset hydraulic circuit. In this case, the curb mold and curb forming machine are set up and adjusted, prior to 2U beginning a curb forming run, in the usual manner. However, immediately prior to starting the run, the hydraulic lines of the lateral offset circuit are disconnected from the lateral offset hydraulic actuator, and connected instead to the positioning means 16. The conventional hydraulic lines and couplers, whic~`-are already installed on the conventional curb forming machine are ideal for this purpose. The conventional couplers include a valve means which substantially prevents leakage of significant q~lantities o~
hydraulic fluid. Thus when the hydraulic lines are disconnected from the lateral offset hydraulic actuator, the actuator is effectively locked in position. Under these conditions, the curb forming operation may proceed in the conventional manner until ~uch times as the curb forming machine arrives at a location, such as near a lane-way, where the top of the curb 3 must be lowered. At this point in the operation, the operator of the curb forming machine uses the manual control for the lateral offset to extend the 2 ~ 7 r~ ~
positioning means 16, thereby lowering the top plate 10 into the mold section 4 and effecting the required lowerlng of the top of the curb 3. Similarly, the operator can raise the top of the curb 3 by retracting the positioning means 16, again using the lateral o~fset controls of the curb ~orming machine.
In a second embodiment of the invention, which also employs manual control ~or adjusting the positioning means 16, a separate hydraulic circuit is added to the conventional curb ¦ forming machine. This eliminates the need for disconnecting the lateral offset hydraulic circuit of the curb forming machine. In addition, a separate curb height adjustment circuit can be designed to provide the operator with a greater degree of control than is possible by using the lateral offset circuit and controls.
A third embodiment of the invention permits the height of the curb to be automatically controlled. It will be recalled that during a conventional curb forming operation, the vertical position of the curb mold is continuously adjusted by using a sensor probe and grade wire to control the vertical adjustment hydraulic circuit of the curb forming machine. Automatic control of the positioning means 16 may be performed in an analogous manner.
In this case, the sensor probe may be disposed on mounting means depending from the height adjusting means 8.
In this manner, the sensor probe moves vertically in direct relation to the top plate 10. A curb height grade wire, in addition to the grade wire described above, is used in conjunction with this second probe to supply control input signals to an automatic hydraulic circuit in a manner directly analogous to that used to adjust the vertical position of the curb forming machine itself. As may be seen ~rom Figure 4, in this embodiment, two grade wires are mounted on support posts 20 set out beside the desired path of the curb 26, which may be at least partially graded and prepared. A first grade wire 22 defines the elevation profile of the curb mold as a whole. Thus grade wire 22 is used to maintain the elevation of the gutter at a predetermined height with respect to the rl s?
ll finished surface of the roadway. A second grade wire 24 is then used to define the profile of the top of the curb, ~or example, as shown in Figure 4, defining a smooth transition between a general curb section and a lane-way.
It will be apparent to those skilled in the art that there are various ways in which the invention may be modified.
For example, the positioning means 16 could electrical instead of hydraulic. In this case, an electric motor and a drive screw might be used in conjunction with appropriate control means to effect the desired positioning of the top plate 10.
In another alternative~ the positioning means 16 might comprise more than one actuator. For example, two actuators, disposed at opposite ends of the top plate 10 could be employed. By this means the two actuators could be independently controlled (for example by using two probes travelling along the grade wire 24) so that the slope of the top plate 10 may be adjusted to more accurately follow the contour of the top of the curb 3, and thereby improve the surface finish, during height transitions.
~ urthermore, it will be seen that in the appended figures, the height adjusting means 8 comprises only a portion of the top of the mold section 4. However, it will be obvious that the height adjusting means 8 could be extended such that the top of the mold section 4 is almost entirely composed of the top platP 10.
Claims (11)
1. An apparatus for forming continuous concrete curbs, which apparatus comprises:
an open ended mold section defining the largest cross-sectional shape of the finished curb;
a hopper generally enclosing the front end of said mold section for directing the flow of plastic concrete into the mold; and height adjusting means adapted for controllably adjusting the height of the finished curb with respect to the lower portion of said curb.
an open ended mold section defining the largest cross-sectional shape of the finished curb;
a hopper generally enclosing the front end of said mold section for directing the flow of plastic concrete into the mold; and height adjusting means adapted for controllably adjusting the height of the finished curb with respect to the lower portion of said curb.
2. An apparatus as claimed in claim 1, wherein said height adjusting means further comprises:
a top plate for shaping the top surface of the curb;
and positioning means for adjusting the vertical position of said top plate with respect to said mold section.
a top plate for shaping the top surface of the curb;
and positioning means for adjusting the vertical position of said top plate with respect to said mold section.
3. A curb forming machine for forming continuous concrete curbs, which machine comprises:
an open ended mold section defining the largest cross-sectional shape of the finished curb;
a hopper generally enclosing the front end of said mold section for directing the flow of plastic concrete into the mold; and height adjusting means adapted for controllably adjusting the height of the finished curb with respect to the lower portion of said curb, wherein said height adjusting means comprises:
a top plate for shaping the top surface of the curb;
positioning means for adjusting the vertical position of said top plate with resect to said mold section;
and control means for controlling said positioning means.
an open ended mold section defining the largest cross-sectional shape of the finished curb;
a hopper generally enclosing the front end of said mold section for directing the flow of plastic concrete into the mold; and height adjusting means adapted for controllably adjusting the height of the finished curb with respect to the lower portion of said curb, wherein said height adjusting means comprises:
a top plate for shaping the top surface of the curb;
positioning means for adjusting the vertical position of said top plate with resect to said mold section;
and control means for controlling said positioning means.
4. A curb forming machine as claimed in claim 3, wherein said control means is a hydraulic circuit controlled by a manual control valve.
5. A curb forming machine as claimed in claim 3, wherein said hydraulic circuit includes the lateral offset adjustment controls of a conventional curb forming machine.
6. A curb forming machine as claimed in claim 3, wherein said control means is an automatically controlled hydraulic circuit.
7. A curb forming machine as claimed in claim 6, wherein automatic control of said control means is effected by control inputs generated by a sensor probe and a grade wire set out along the path of the curb so as to define the elevation of the top of the curb.
8. A method of continuously forming a concrete curb, which method comprises the steps of:
maintaining a curb mold at a predetermined elevation with respect to the finished grade of an adjacent road surface;
supplying plastic concrete to said mold, and compacting it therein so as to form the curb; and controllably varying the vertical position of an upper portion of said curb mold, with respect to said predetermined elevation, so as to selectively vary the height of said curb.
maintaining a curb mold at a predetermined elevation with respect to the finished grade of an adjacent road surface;
supplying plastic concrete to said mold, and compacting it therein so as to form the curb; and controllably varying the vertical position of an upper portion of said curb mold, with respect to said predetermined elevation, so as to selectively vary the height of said curb.
9. A method of continuously forming a concrete curb as claimed in claim 8, wherein said controllably varying the vertical position of an upper portion of said curb mold is effected by manual control by an operator.
10. A method of continuously forming a concrete curb as claimed in claim 8, wherein said controllably varying the vertical position of an upper portion of said curb mold is automatic.
11. A method of continuously forming a concrete curb as claimed in claim 10, further comprising the steps of:
continuously adjusting the vertical position of said curb mold in response to control inputs generated by a first grade wire and sensor probe; and independently adjusting the vertical position of said upper portion of said curb mold in response to control inputs generated by a second grade wire and sensor probe
continuously adjusting the vertical position of said curb mold in response to control inputs generated by a first grade wire and sensor probe; and independently adjusting the vertical position of said upper portion of said curb mold in response to control inputs generated by a second grade wire and sensor probe
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2043773 CA2043773A1 (en) | 1991-06-03 | 1991-06-03 | Variable top curb mold |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2043773 CA2043773A1 (en) | 1991-06-03 | 1991-06-03 | Variable top curb mold |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2043773A1 true CA2043773A1 (en) | 1992-12-04 |
Family
ID=4147722
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2043773 Abandoned CA2043773A1 (en) | 1991-06-03 | 1991-06-03 | Variable top curb mold |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2043773A1 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6709195B2 (en) | 2000-09-29 | 2004-03-23 | N. Piccoli Construction | Moveable tailpiece for attachment to a curb forming machine for producing low curb profiles |
| BE1017106A3 (en) * | 2006-04-21 | 2008-02-05 | Drion Constructie Bv Met Beper | Mold for making concrete kerbstones, has upper wall with adjustable shape part comprising pivoting slats |
| CN101270564B (en) * | 2008-04-28 | 2010-06-09 | 江苏四明工程机械有限公司 | Operation mechanism of self-propelled multifunctional border stone slip form machine |
| EP2737983A3 (en) * | 2012-11-29 | 2017-11-01 | Elematic Oyj | Method and apparatus for casting concrete products |
| EP3839143A1 (en) * | 2019-12-20 | 2021-06-23 | Wirtgen GmbH | Slipform paving machine with variable height mold |
| US11047095B2 (en) | 2018-12-28 | 2021-06-29 | Wirtgen Gmbh | Variable height offset mold |
| US11421389B2 (en) | 2018-12-28 | 2022-08-23 | Wirtgen Gmbh | Variable height mold |
-
1991
- 1991-06-03 CA CA 2043773 patent/CA2043773A1/en not_active Abandoned
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6709195B2 (en) | 2000-09-29 | 2004-03-23 | N. Piccoli Construction | Moveable tailpiece for attachment to a curb forming machine for producing low curb profiles |
| BE1017106A3 (en) * | 2006-04-21 | 2008-02-05 | Drion Constructie Bv Met Beper | Mold for making concrete kerbstones, has upper wall with adjustable shape part comprising pivoting slats |
| CN101270564B (en) * | 2008-04-28 | 2010-06-09 | 江苏四明工程机械有限公司 | Operation mechanism of self-propelled multifunctional border stone slip form machine |
| EP2737983A3 (en) * | 2012-11-29 | 2017-11-01 | Elematic Oyj | Method and apparatus for casting concrete products |
| US11047095B2 (en) | 2018-12-28 | 2021-06-29 | Wirtgen Gmbh | Variable height offset mold |
| US11421389B2 (en) | 2018-12-28 | 2022-08-23 | Wirtgen Gmbh | Variable height mold |
| EP3839143A1 (en) * | 2019-12-20 | 2021-06-23 | Wirtgen GmbH | Slipform paving machine with variable height mold |
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