WO2000000706A1

WO2000000706A1 - Partition walls and parts therefore

Info

Publication number: WO2000000706A1
Application number: PCT/DK1999/000366
Authority: WO
Inventors: Bjarne Kongsgaard; Jes Valdemar Willumsen
Original assignee: Ikadan System A/S
Priority date: 1998-06-29
Filing date: 1999-06-29
Publication date: 2000-01-06
Also published as: DK199800832A; AU4603699A

Abstract

The invention concerns a partitioning wall system for stable furnishings. The partitioning wall system comprises posts and planks, and where the planks are intended for interaction with the post for being fixed to the posts. The post may be a post with a U-shaped cross-section or a post with a T-shaped cross-section. Projections are formed on branches of the U-shaped cross-section or on a rail on the T-shaped cross-section. Recesses are formed at outer sides or at inner sides of the planks. When the plank becomes mounted to the post, the projections engage the recesses in such a way that the planks in this way are fixed to the post. In a preferred embodiment there is provided a jacket creating the interaction between the posts and the planks. The jacket is provided with means for fastening the jacket to the post and for fastening the planks to the jacket. Fastening means in the form of projections and recesses imply that the system is very quickly assembled and disassembled. Furthermore the system is also considerably more hygienic that known systems as the projections completely engage the recesses when the planks are mounted to the post or alternatively to the jacket.

Description

Partition Walls and Parts therefore

The present invention relates to a partitioning wall system for separation between pens in a pen system in a stable, which partitioning wall system comprises a number of planks intended for being held by posts so that ends of the planks are intended for interaction with the posts and to be fixed to the posts by means of fastening means. The invention also concerns parts therefore.

Background of the invention Pen systems are known for piggeries, among others, where planks made of wood or plastic are fastened to metal posts having a U-shaped cross-section. The posts are initially fastened to the stable floor or to the stable wall in vertical upright position so that the U-shaped cross-section lies in a horizontal plane and with the groove formed between the branches of the U-shaped cross-section extending vertically. The planks are then mounted between opposite posts so that ends of the planks extend into the groove between the branches of posts with U-shaped cross-section. The end of the planks is finally fastened to the posts by means of screws or screw bolts.

It has appeared that the building up of pen systems by means of posts with a U-shaped cross-section and mounting of the end of plank in the groove in the posts result in good possibilities for building the pen system quickly, and result in good possibilities for building up the pen system individually under consideration to the layout of the stable and under consideration to which livestock the pen system is intended for, e.g. pigs, cattle, sheep or other livestock. Furthermore it is possible quickly to change the layout of the pen system, e.g. if parts of the pen system are to be used as a farrowing pen and other parts of the pen system are to used as porker pen, or if the need for different pen systems is changing all the time. Furthermore, it is possible with such a system to maintain a high degree of hygiene.

However, the pen system has the drawback that the good possibilities concerning the building up of the pen system and concerning changing the layout is made difficult substantially by the fastening means between the posts and the planks being conven- tional screws or screw bolts. Such fastening means are time-consuming to tighten and loosen and may furthermore contribute to dirt collection around the screws or bolts.

The present invention Thus it is the purpose of the present invention to provide fastening means between the posts and the planks which do not constitute a limitation in the otherwise high flexibility of the pen system and which at the same time increases the hygiene in the pen system.

This purpose is achieved with a partitioning wall system peculiar in that the fastening means comprise a number of projections and a number of recesses, and that the projections are intended to extend into the recesses when the ends of the planks interact with the posts.

By using projections and recesses as mutual fastening means between posts and planks there is achieved a substantially easier and quicker mounting and demounting of the planks from the posts. At the same time, the hygiene is considerably improved as it is possible to form the projections and the recesses in such a way that these fit completely together when the projections and the recesses are in mutual engagement.

A preferred embodiment of the invention is peculiar in that the projections extend from at least one branch of posts with U-shaped cross-section and inward between the branches, and that the recesses are formed at at least one outer side of the planks in immediate vicinity of the end of the planks, and that the branches of the posts with U- shaped cross-section is intended to extend about the end of the plank along the outer sides of the planks.

By using a post with a U-shaped cross-section and where the branches of the U-shaped cross-section extend around the end of the planks, it is much quicker to mount the planks in the posts while at the same time there is established a stable securing of the planks in the post. The fastening means, the projections on the post and the recesses at the outer side of the planks, respectively, are at the same time completely hidden when the planks are mounted in post, which contributes to the high hygiene.

An alternative embodiment of the invention is peculiar in that the projections extend outward from a rail on a post with T-shaped cross-section, that the planks have an opening at the end of the planks, that the recesses are formed at the inner side of the planks in immediate vicinity of the ends of the planks, and that the rail on the post with T-shaped cross-section is intended to extend into the opening along inner sides of the planks.

By using a post with a T-shaped cross-section and where a rail of the T-shaped cross- section extends into an opening at the end of the planks and within inner sides of the planks, there is similarly achieved that the partitioning walls are quick to mount and there is also established a stable securing of the planks in the post. However, the hy- giene is further increased because the abutment surface between the inner side of the plank and rail of the T-shaped cross-section of the post is now established along inner sides of the planks instead of along outer sides of the planks.

In a preferred embodiment, the system is peculiar in that a jacket is intended to extend between the end of the planks and the posts with U-shaped cross-section, that the jacket is provided with a first set of fastening means for securing the jacket to the posts with U-shaped cross-section and a second set of fastening means for securing the end of the planks to the jacket.

By using a jacket for the interaction between post and planks there is achieved a more flexible system. The jacket is provided with means for securing the jacket to the post and with means for securing the planks to the jacket. In a preferred embodiment, the jacket has a U-shaped cross-section with a width between outer sides of the branches of the U-shaped cross-section which is largely equal to a width between inner sides of a U-shaped cross-section of a post. The jacket is thus capable of extending inward between branches of the U-shaped cross-section of the post. At the same time, the jacket has a width between branches of the U-shaped cross-section of the jacket which is mainly equal to a thickness of the planks. The planks are thus capable of extending inward between the branches of the U-shaped cross-section of the jacket.

List of Figures The invention will hereafter be described in more detail with reference to the accompanying drawing, where:

Fig. 1 is a draft with a plane view of how a post, a jacket and planks according to the invention interact, Fig. 2 is a draft with a plane view of a foot for the post according to the invention,

Fig. 3 a draft with a perspective view of the post according to the invention, Fig. 4 is a draft with a plane view of the foot for the post according to the invention, Fig. 5 is a draft with a perspective view of a tier for fastening the foot to the post according to the invention to a floor consisting of gratings, Fig. 6 is a draft with a plane view of the jacket according to the invention,

Fig. 7 is a draft with a perspective view of planks according to the invention and segments according to the invention, Fig. 8 is a draft with a perspective view of a preferred embodiment of a jacket according to the invention and a lock according to the invention, and Fig. 9 and 10 are images of a possible embodiment of a post or jacket and planks, respectively, for a partitioning wall system according to the invention.

Description of the invention

Fig. 1 shows a post 1 according to the invention, a jacket 2 according to the invention and a number of planks 3 according to the invention. The post 1 consist of a section with U-shaped cross-section (see Fig. 3). The post is provided with a foot 4 of plastic.

The foot is moulded around a lower part 5 of the post. The foot 4 is provided with a bolt 6 extending upward from the foot within the U-shaped cross-section of the post.

In a higher position, the post is provided with a further bolt 7 fastened to a back 8 of the U-shaped cross-section of the post. The bolt 7 extends outward between branches

9,10 (see Fig. 3) of the U-shaped cross-section and upwards along a longitudinal axis A of the post. The foot is between the branches and within the U-shaped cross-section of the post provided with a gradation 11.

The jacket 2 is made of plastic and has also a U-shaped cross-section. The jacket has a width b (see Fig. 6) between outer sides of branches 12,13 (see Fig. 6) of the U-shaped cross-section which is largely equal to a distance B between branches 9,10 of the U- shaped cross-section of the post 1. The jacket is provided with a bevelling 14 intended for interacting with the gradation 11 within the U-shaped cross-section of the post. The post is furthermore provided with a first groove 16 intended for interacting with the first bolt 6 in the foot of the post, and a second groove 17 intended for interacting with the second bolt 7 in the higher position up along the post. The jacket is within the U-shaped cross-section provided with means in the shape of projections 18 (see Fig. 6) for securing a number of planks 3 to the jacket.

Fig. 2 shows with stippled contour the post 1 as seen from under the foot 3 and upwards in parallel with the longitudinal axis A (see Fig. 1 ) of the post. The foot is, as mentioned, made of plastic which is moulded around the lower part of the post (see Fig. 1). The post is made of metal, preferably galvanised steel, stainless steel or aluminium. The foot is provided with two arched pieces 19 extending outward from the post and provided with holes 20 for, by means of screw bolts or screws, to secure the post to a base. Fig. 2 shows furthermore, how the gradation 11 is formed by means of the plastic moulded around the lower part of the post. At the same time there is shown the lower bolt 6 extending upward from the foot (see Fig. 1) between the branches 9,10 of the U-shaped cross-section.

In an alternative embodiment, the foot can be made of metal. If the post is also made of metal, the foot may then either constitute an integrated part of the post, or the foot may constitute a separate part fastened to the lower part of the post, e.g. by welding or soldering. If the foot constitutes an integrated part of the post, the foot may initially be formed in connection with punching of material from metal sheets for the making of the post and thereafter bent for thus making the foot. If the post is made of plastic, the foot can constitute a separate part fastened to the post in a suitable way. Fig. 3 is a perspective view of a post 1. Fig. 3 shows how the foot 4 of plastic is moulded around the lower part 5 of the post. At the same time it is shown how moulding of the plastic about the lower part of the post simultaneously provides the gradation 11 within the U-shaped cross-section of the post so that there is formed a step from an abutment surface 15 for the foot and upwards along the back 8 and along the branches 9,10 of the U-shaped cross-section of the post.

The foot is extending a substantial distance L up along the post. This means that if loads from the livestock or by the building of the partitioning wall system apply bending moments to the post, a possible deflection of the post becomes substantially less than if the post was only provided with a foot only fastened to a lower end of the post. Besides, the foot is formed so that the foot extends along a regular curve B from the abutment surface for the foot and upwards along the post. This implies that the risk is minimised for the animals in the pen system becoming damaged by the posts in the partitioning wall system.

Fig. 4 shows how the lower part of the post is moulded around with plastic as seen in a plane view perpendicularly to longitudinal axis A of the post. In the back of the U- shaped cross-section, the post is provided with a number of holes 21 (only one hole shown) intended for fastening the post to a wall up along which the post possibly may be situated. The holes may also be used for fastening to the post other stable equipment like automatic fodder dispensers. Furthermore, a hole (not shown) at a higher position up along the post will be used for fastening the further bolt 7 (see Fig. 1). The foot extends evenly outward from the lower part of the post to the curved pieces with the through-going holes, the curved pieces constituting abutment surface for mounting the post to the floor.

The post in the shown embodiment is shown as if only the lower part of the post is moulded around with plastic. If the post is made of metal, the whole post will, however, be moulded around with plastic in a preferred embodiment. The upper part of the post, though, will only be applied a thin coating of plastic in order to create sufficient sealing between an outer side of the back of the post and a wall or another post on which the back of the post may abut. If the post is made of plastic, it is of course not necessary to provide the upper part of the post with a coating of plastic, as the foot then will constitute an integrated part of the post and not constitute a separate part moulded around the lower part of the post as in the shown embodiment where the post is made of metal.

Fig. 5 shows a tier for, by means of a screw bolt, fastening the post according to the invention to a floor consisting of gratings. The tier consists of two blocks 22,23. A lower block 22 is made of plastic and a nut 24 shown with stippled contour is moulded into the plastic. The lower block 22 is furthermore provided with a spout 25 with a hole 26 wherethrough a screw bolt (not shown) may extend downward to the nut. The spout has a collar 27 intended for abutting on a shoulder in the upper block 23. The lower block 22 is furthermore provided with grooves 28,29 extending about the spout 25 in an angle of about 90° each.

The upper block 23 is also made of plastic and provided with a hole 30 wherethrough the spout 25 on the lower block 22 may extend. With stippled contour it is shown that the hole in the upper block is provided with a shoulder 31 intended as abutment for the collar 27 on the spout on the lower block. The lower block is furthermore provided with pins 32,33 intended for extending downward into the grooves 28,29 on the lower block.

The two blocks are intended for being used in fastening the foot of the posts to a floor consisting of gratings. Before the abutment surface on the foot is laid on the upper side of a grating constituting the floor in the pen, screw bolts are mounted through the holes in the foot. The upper block and the lower block are assembled so that the collar on the spout engages the shoulder in the upper block. The upper block and the lower block are mutually rotated so that the length of the two blocks are in the same direc- tion. Then the two assembled blocks are mounted on the screw bolt passed through one of the holes in the foot of the post. The foot of the post is thereafter brought to abut on the top side of the grating so that the lower block is situated at a level under an underside of the ribs in the grating, and so that the upper block is situated in an interspace between two ribs on the grating. The screw bolt may then be tightened, and because the pins in the upper block are engaging the grooves in the lower block, the lower block will be stopped in rotating only by the rotation of the screw bolt.

Fig. 6 are perspective views of the jacket 2 according to the invention. In the shown embodiment, the jacket has a U-shaped cross-section and is provided with the bevelling 14 intended for interacting with the corresponding gradation 11 at the foot 4 of the post 1. The jacket is also provided with the grooves 16,17 intended for interacting with the bolts 6,7 at the foot of the post and at a higher position of the post, respectively. Within the U-shaped cross-section of the jacket, the jacket is provided with projections 18 extending inward between the branches of the U-shaped cross-section.

The projections are preferably only provided on one of the branches 12 of the U- shaped cross-section, but may in an alternative embodiment be provided on both branches 12,13 of the U-shaped cross-section. The projections are intended for interacting with recesses 34 in the planks 3 which are intended for being mounted between the branches of the U-shaped cross-section of the j acket.

The projections may either have shape as knobs as shown in the Figure, and the recesses in the planks may then have form as indentations at the outer side of the planks. Alternatively, the projections may have form as one or more beads extending along at least one of the branches of the U-shaped cross-section of the jacket, and the recesses in the outer side of the planks may then have form as grooves extending crosswise of a longitudinal direction of the planks in immediate vicinity of the end of the planks and which the beads are intended to engage when the end of the planks are mounted in the U-shaped cross-section of the jacket. The projections may be formed by moulding the jacket, alternatively the post, so that the projections constitute an integrated part of the jacket or the post. If the projections are provided in the posts and these are made of metal, it becomes possible to form the projections by mounting small studs in holes formed in one or both of the branches of the U-shaped cross-section of the post. The studs may then either be made of plastic or rubber which is pressed into the holes in the branches of the U-shaped cross-section and becomes secured in the branches by elastic deformation of the plastic or rubber. The studs may also be made of metal which is pressed into the holes in the branches of the U-shaped cross-section. If the post is made of plastic, studs of metal become secured in the holes by elastic deformation of the plastic of which the post is made. If the post is made of metal, it will be advantageous to make the post of aluminium, as studs of a hard metal possibly may become secured in the holes by elastic or plastic deformation of the aluminium. Alternatively, the studs may be soldered, screwed, or in other ways fastened in the holes.

Fig. 7 shows a preferred embodiment of a number of planks 3 for mounting in a jacket 2. The planks may either be made as longitudinal, whole planks 3', or may be made as segments 3" of a plank, the segments being intended for disposal between whole planks 3'. The whole planks are preferably made of extruded plastic panels and are provided with through-going holes which the projections at the inner side of the branches on the U-shaped cross-section (see Fig. 6) may engage.

The segments constituting parts of a plank are preferably I-shaped and intended for abutting on other segments so that a plank wall is formed with through-going holes between adjacent segments with I-shaped cross-section. In the shown embodiment there is mounted a longitudinal plank above and below, and between the longitudinal planks segments of a plank are disposed so that the segments are secured by the uppermost and the lowermost plank, and so that holes between adjacent segments are formed in the middle of the assembled plank wall.

Fig. 8 shows an upper part of a preferred embodiment of a jacket 2. A lock 35 is in- tended for being mounted on the upper part of the jacket for securing the planks so that these cannot be displaced upwards or downwards in relation to the jacket. At the upper part, the jacket is provided with a mainly dovetailed rail 36 extending at the outer side of one of the branches of the U-shaped cross-section. The lock has a foot 37 provided with a mainly dovetailed groove 38 intended for interacting with the rail at the outer side of one of the branches of the U-shaped cross-section of the jacket.

The lock has a head 39 provided with a stop 40 which also is provided with an extension 41 intended for tilting the head of the lock relatively to the foot of the lock about a flexible link connection 42 formed between the head 39 and the foot 37. After the planks have been mounted between the branches of the U-shaped cross-section for the jacket, and when the groove 38 on the lock is passed down around the rail 39 on the jacket, the stop 40 on the lock will abut on the top side of the uppermost plank and secure the planks so that the planks cannot be displaced upward in the U-shaped cross- section of the jacket.

The lock is, as mentioned, provided with a flexible link connection 42 making possi- ble to tilt the head 39 of the lock in relation to the foot 37 of the lock when the extension 41 is moved backwards with a finger in relation to the extension of the stop. The link connection is formed in the shown embodiment by making the lock, which is preferably of plastic, with a curve extending between the head and the foot. The link connection is intended to make it possible to displace the stop away from the jacket while the foot is still fastened to the jacket by the lock via the rail. When the stop is moved away from its abutment with the top side of the uppermost plank, the planks may be displaced upwards in the U-shaped cross-section of the jacket.

Displacement of the planks upwards may be necessary at the replacement of the planks or if the planks are desired secured temporarily at an elevated position relative to the jacket and the post, e.g. if gratings constituting the floor surface has to be removed or moved for making access to manure channel etc. that may be located under the floor gratings. In the latter case, the stop is moved away from its abutment with the upper edge of the uppermost plank, whereafter the planks are lifted. When the planks are lifted to a position above the stop, the stop is moved forward again by means of the flexible link connection, and the stop will then abut on the lower edge of the lowermost plank and secure the planks in the lifted position. The stop may also abut on against another edge, like an edge on a reinforcing rib formed at the end of the planks (see Fig. 9 and 10).

The invention is described above with reference to a specific embodiment of post, jacket, and planks according to the invention. It will be possible in alternative embodiments to fasten the posts to floor or wall in another way that with a foot. E.g. in certain cases it will be advantageous to omit securing the planks to e.g. gratings in the floor as it then becomes difficult to remove the gratings, e.g. if there is to be cleaned under the gratings. Then it will be more advantageous to fasten the posts to wall or to fasten the posts to a lower foundation under the gratings making up the actual floor and to provide a mechanism making possible to demount the posts from the securing to the lower foundation.

It will further be possible to omit the jacket and instead to mount the planks directly to the post. The posts then have to be provided with projections corresponding to the recesses in the planks as well as the jacket is provided with such projections. The posts preferably have a U-shaped cross-section with branches of the U-shaped cross-section extending around the jacket. In the embodiment where the jacket is omitted, it will be possible to impart the post a T-shaped cross-section where the foot of the T constitute a rail. This rail may then be used for extending inward into the end of the planks which are hollow then and provided with an opening at the end of the planks. Hereby there is achieved a more hidden mounting of the planks on the post and thereby also a more hygienic mounting. Outer sides of the rail constituting the foot of the T then has to be provided with projections corresponding to recesses which then have to be pro- vided at inner sides of the planks instead of outer sides of the planks.

Claims

1. Partitioning wall system for separation between pens in a pen system in a stable, which partitioning wall system comprises a number of planks intended for being held by posts so that ends of the planks are intended for interaction with the posts and to be fixed to the posts by means of fastening means, characterised in that the fastening means comprise a number of projections and a number of recesses, and that the projections are intended to extend into the recesses when the ends of the planks interact with the posts.

2. Partitioning wall system according to claim 1, characterised in that the projections extend from at least one branch of posts with U-shaped cross-section and inward between the branches, and that the recesses are formed at at least one outer side of the planks in immediate vicinity of the end of the planks, and that the branches of the posts with U-shaped cross-section is intended to extend about the end of the plank along the outer sides of the planks.

3. Partitioning wall system according to claim 1, characterised in that the projections extend from at least one branch of posts with U-shaped cross-section and outward from the branch, and that the recesses are formed at at least one inner side of the planks in immediate vicinity of the ends of the planks, that the planks have an opening at the end of the planks, and that the branches of the posts with U-shaped cross-section are intended to extend into the opening along inner sides of the planks.

4. Partitioning wall system according to claim 1, characterised in that the projections are formed on tongues extending from a top and a bottom of the posts and outward from the post, and that the recesses are formed at an upper edge and a lower edge of the planks in immediate vicinity of the end of the planks, that the planks have an opening at the end of the planks, and that the tongues on the post are intended to extend about the upper edge and the lower edge of the planks.

5. Partitioning wall system according to claim 1, characterised in that the projections extend outward from a rail on a post with T-shaped cross-section, that the planks have an opening at the end of the planks, that the recesses are formed at the inner side of the planks in immediate vicinity of the ends of the planks, and that the rail on the post with T-shaped cross-section is intended to extend into the opening along inner sides of the planks.

6. Partitioning wall system according to claim 2 or 3, characterised in that the projections on at least one of the branches with U-shaped cross-section consist of knobs, and that the recesses at the outer side and the inner side, respectively, of the planks consist of through-going holes extending between opposite outer sides of the planks.

7. Partitioning wall system according to any preceding claim, characterised in that a jacket is intended to extend between the end of the planks and the posts with U- shaped cross-section, that the jacket is provided with a first set of fastening means for securing the jacket to the posts with U-shaped cross-section and a second set of fastening means for securing the end of the planks to the jacket.

8. Partitioning wall system according to claim 7, characterised in that the jacket has a U-shaped cross-section, that the jacket at an outer side of a back of the jacket is provided with at least one downward facing groove, that a post with U- shaped cross-section at an inner side of a back of the post is provided with at least one upward facing bolt, and that the bolts on the post are intended for interaction with the grooves on the jacket.

9. Partitioning wall system according to claim 7 or 8, characterised in that the jacket has a U-shaped cross-section, that projections extend from at least one branch of the jacket with U-shaped cross-section and inward between the branches, and that the recesses are formed at at least one outer side of the planks in immediate vicinity of the end of the planks, and that the branches of the jacket with U-shaped cross-section are intended for extending about the end of the planks along the outer side of the planks.

10. Partitioning wall system according to any preceding claim, characterised in that the post is made of metal, alternatively of plastic, that the post is provided with a foot made of plastic and moulded around a lower part of the post, alternatively made of metal, constituting a separate part of the post, and fastened to the post, alternatively made of metal, constituting an integrated part of the post, that the foot extends along a substantial part of the post from a lower part of the post and upwards along the post, and that the foot is provided with means for fastening the post to a base.

11. Partitioning wall system for separation between pens in a pen system in a stable, which partitioning wall system comprises a number of planks intended for being held by posts so that ends of the planks are intended for interaction with the posts and to be fixed to the posts by means of fastening means, characterised in comprising a tier consisting of an upper block and a lower block, that the two blocks are intended for mutual engagement, that the two blocks are mutually rotatable and provided with means for stopping a mutual rotation of the two blocks, preferably by stopping a rotation in an angle between 0 and 90 degrees.

12. Partitioning wall system according to any preceding claim, characterised in that upper and lower edges of the planks are provided with tongue and groove for engaging edges of other adjacent planks, and that outer sides of a plank extend in immediate extension of outer sides on an adjacent planks when the planks are in en- gagement by means of the tongue and groove connection.

13. Partitioning wall system for separation between pens in a pen system in a stable, which partitioning wall system comprises a number of planks intended for being held by posts so that ends of the planks are intended for interaction with the posts and to be fixed to the posts by means of fastening means, characterised in that the planks consist of segments which are I-shaped, that the segments are intended for mutual abutment with the I-shape turned so that foot and head of the I-shape abut on each other for forming a assembled plank with holes formed between the shaft of juxtaposed I-shaped segments.

14. Partitioning wall system according to claim 13, c h a r a c t e r i s e d in that upper and lower edges of the segments are provided with a tongue and groove for mutual interaction with adjacent edges of planks or lists, that the upper edge of the segments engages the lower edge of an overlying plank or list, and that the lower edge of the segments engages the upper edge of an underlying plank or list so that the segments are fixed between the overlying plank or list and the underlying plank or list.

15. Partitioning wall system for separation between pens in a pen system in a stable, which partitioning wall system comprises a number of planks intended for being held by posts so that ends of the planks are intended for interaction with the posts and to be fixed to the posts by means of fastening means, c h a r a c t e r i s e d in that the sys- tem comprises a lock for securing the planks relative to the posts in a direction in parallel with a longitudinal axis of the post, that the lock is provided with means for fastening the lock to the post, alternatively to a jacket, and that the lock furthermore is provided with means for securing an upper edge, alternatively a lower edge, of a plank in a given position opposite the post.