GB2487593A

GB2487593A - Connector for log cabin construction

Info

Publication number: GB2487593A
Application number: GB1101578.1A
Authority: GB
Inventors: Mark Andrew Chatfield
Original assignee: NORWEGIAN LOG BUILDINGS Ltd
Current assignee: NORWEGIAN LOG BUILDINGS Ltd
Priority date: 2011-01-28
Filing date: 2011-01-28
Publication date: 2012-08-01
Anticipated expiration: 2031-01-28
Also published as: GB201101578D0; GB2487593B

Abstract

between two construction members such as a beam and a post. In a preferred aspect a plurality of beams are secured by their ends to the post, in a stacked configuration with seals between adjacent beams. The connection of each beam to the post is made using a tie member which is received in elongate undercut slots in the abutment faces of the respective components. The slots are co-aligned to form a cavity extending between the undercut of one face and the undercut of the other face and the tie member is accommodated in the cavity, the tie member having first and second opposite side regions which occupy undercut regions of the respective slots, with a neck region extending between them. In a preferred arrangement the tie member is provided with a feed ramp to ease entry of the tie member into the cavity defined by the aligned slots and draw the abutted faces together. The invention also extends to a building method.

Description

Joint for use in constructing buildings

Field of the Invention

The invention relates to the field of construction of buildings such as log cabins. The invention relates in particular to a joint between two construction members such as a beam and a post.

Background

The traditional construction technique for building log cabins or houses involves providing logs formed with machined upper and lower flat side regions, and placing the logs one on top of the other to build a wall. The flat regions may me formed with elongate recesses and ridges which mesh with corresponding ridges and recess in the adjacent log.

At corner regions where logs meet the ends are alternately crossed over to form a short projection of the log ends beyond the corner itself. The logs end regions require complex machining to permit a tight and solid meshing of the mutually orthogonal alternately stacked logs. A very strong and durable joint is however produced.

Recently attempts have been made to simplify the corner regions so 4.

* ° that this complex and expensive machining may be avoided. In some cases a vertical corner post is provided up to which log ends are placed and joined by bolts or other ties. This also provides a cleaner and less rustic appearance for the cabin. For example, the S. * patent application US 2009/0199497 provides means for securing multiple horizontal logs to an upright post which utilizes a two piece key which cooperates with undercut vertical channels formed in the horizontal logs and upright post. A spike is driven between the two pieces of the key in order to force them against the inside of the channels so as to retain the post and log or beam in position.

One of the channels is provided with an elongate plastics insert which is described as a key slide and which provides a slidable but snug fit for the key pieces.

It is an object of the present invention to provide a joint assembly for use in constructing buildings and a method of constructing buildings such as, but not limited to, log cabins which avoids the complex machining of tradition cross-over methods and which is quicker and simpler to assemble than the prior art log and post methods, such as that described above.

Su.umiary of the invention According to one aspect of the invention there is provided a joint for use in constructing buildings which serves to retain one construction member in abutment with another construction member, wherein opposing abutted faces of the construction members are each provided with an elongate undercut slot, each of which slots is co-aligned to form a cavity extending between the undercut of one face and the undercut of the other face, wherein a tie member is accommodated in the cavity, the tie member having first and second opposite side regions which occupy S. Se* * undercut regions of the respective slots, with a neck region extending between the opposite side regions so as to tie one construction member to the other.

According to another aspect of the invention there is provided a method of joining one construction member to another in constructing a building comprising:

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* providing first and second construction members each having a face formed with an elongate undercut slot, abutting the faces and aligning the facing slots so as to form a unitary elongate cavity comprising the two undercut slots, providing a tie member having first and second opposite side regions which are configured to occupy undercut regions of the respective slots, with a neck region extending between the opposite side regions, and engaging the tie member into the cavity so that the first and second side regions occupy the respective undercut regions so as to tie one construction member to the other.

In either of the above two aspects the invention may be characterised by one or more of the following features or combinations of features.

A spacing between the opposite side regions of the tie member permitted by the neck region thereof should be marginally less than dimensionally required so that the neck region is maintained under tension with the tie member side regions engaged with the said undercut regions of the slots.

This may be achieved by selection of a suitable size of the tie irneinber, and/or control of the slot depths and cross-section.

Typically the ties will be formed with a preselected size and configuration and the undercut shape and depth will be matched to the tie member when the beams are machined. Thus once the components are on site, construction is a simple matter of laying the construction members (such as a beam and a post) next to one * Is...

* another, aligning facing slots and driving home the tie member to form the joint.

By maintaining a tie member tension the construction members are drawn tightly together, which permits a strong and weather proof : joint to be made. *0. *

At least one end of each slot, and preferably both ends of each slot, is/are open-ended to permit entry and sliding engagement of the tie member along the slot to form the joint.

The undercut slots preferably slot have a T-section, although other sections are possible provided that the slot prevents withdrawal of the tie member side regions through the slot.

The tie member preferably has a generally I-section configuration.

Typically, the tie member is elongate along the slot direction and has a front end region and a rear end region, with the side regions extending between the front and rear end regions. Thus the tie member may have the form of a short I-beam.

Each of the opposite first and second side regions of the tie member may comprise at least one shoulder portion which defines an inward facing surface in contact with the undercut region of the slot which it occupies.

In a preferred arrangement a feed ramp is provided which acts between a leading edge of each shoulder portion inward facing surface and a corresponding outward facing surface of the undercut region of the slot, thereby to ease entry of the tie member into the cavity defined by the aligned slots and draw the abutted faces together.

The feed ramp is preferably provided in the leading edge of the shoulder portion inward facing surface. The feed ramp could however alternatively, or additionally be formed in a leading end of the undercut. fl.o

In a preferred embodiment of the invention there is provided a tie member which has a generally I-section configuration so that there . : are two shoulder regions and two corresponding feed ramps at the tie * 20 member leading edge disposed side-by--side.

A rear end region of the tie may also be provided with counterpart feed ramp or ramps so that the tie member may be slid into the slot with either the front end or rear end leading.

The tie member is typically unitary construction, which is to say it is formed as a single-piece component. Preferably the tie member is a made of metal or plastics material. In a preferred embodiment the tie member is made of injection moulded polypropylene.

In a preferred arrangement the tie member is elongate and the neck region of the tie member is provided with a series of longitudinally spaced surface depressions which reduce the volume or material used in forming the tie member and the surface area of the tie available for contact with the slot walls. This eases entry of the tie member

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into the slots. The depressions may be of any shape, but are preferably generally rectangular with radiused corners.

In practice at least one construction member is a beam and the other may be a post. The method may however be used to join beam to beam S or post to post or indeed any other building member to another. A corner post will typically be vertically oriented and may have a generally square cross-section. Adjacent inside faces of the post will be formed with undercut slots. The outside faces will be left without slots so as to provide a clean finish. Further slots can of course be included if the post serves to join three or four walls (which may the case when internal dividing walls are required). The posts need not be rectilinear in section. For example the posts may be triangular or pentagonal or hexagonal etc., according to architectural requirements. Thus the angles between post and beam can be acute or obtuse or perpendicular.

In a preferred aspect of the invention one construction member is a generally vertical post with an elongate longitudinal slot formed therein and the other is a beam having an end face with an elongate slot formed therein so that the end face of the beam is joined to a :20 side face of the post. Several beams will be stacked to the post to * form a wall.

The tie member may have a length which is the same as, or slightly less than, the depth of a construction member measured in the direction of the channel length, so that one tie member is used to join each such construction member, and fills the length of each channel.

Thus in yet another aspect of the invention a plurality of construction members may be joined together by the tie members and a proportion of the construction members may be stacked one on top of the other, and a seal or beading is disposed between tie members which are themselves stacked on top of each other, thereby to weather proof the stacked joints. The seal may be a liquid sealant which solidifies or a gasket or elastomeric bead.

When joining any construction member to another it is preferred that the facing surfaces of the construction members match at the abutment. Thus an intimate and watertight joint is possible.

In a further aspect of the invention the building is a log cabin and one or both of said construction members are formed of wood. Usually there will of course be multiple joints in accordance with the invention. Thus the invention provides a log cabin comprising a joint as hereinbefore described.

The first and second construction members may be manufactured from any construction material, including wood, metal, concrete, plasterboard, plastics and composites and may be made from either the same or different construction materials.

Preferably both of the construction members are wooden logs. In other embodiments, at least one of the construction members is a wooden log. In a preferred embodiment the first construction member is a post which is upstanding, preferably vertically, and

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**SsSS * * the second construction member is a wall section.

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* ***S* * In a preferred embodiment, the tie member is a single piece member and the joint may be formed solely by the first and second construction means and the joining means. The tie member thus preferably comprises no portions which may move relative to one another, This simplifies the process for assembly of the joint as well as simplifying the process by which the joining means is manufactured.

The feed ramp may have a profile which is linearly tapered or curved or rounded. When the joining means is slidably engaged with the first and second construction members the feed ramp urges them towards each other if they are not already intimately joined.

The following is a description, by way of example only, and with reference to the figures of the drawings, of one way of putting the present invention into effect.

In the drawings:-S Figure 1 is an exploded isometric view of the components of joints in accordance with the invention between a post and two horizontal logs.

Figures 2A to 2C show respectively a front end-on view, a side view and a plan 2C view of a tie member or key shown in figure 1.

Figure 3 is a transverse cross sectional view through a log shown in figure 1.

Figure 4 is a vertical cross sectional view through a log shown in figure 1.

Figure 5 is a plan view from above of a vertical post useful in the present invention.

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Specific enibodintent Figure 1 shows an exploded view of a joint assembly of the present invention. The assembly comprises a vertically upstanding post (1) of generally square cross section. The post is made from wood. The post forms one end of a wall structure. Another similar post (not shown) is situated a predetermined distance from the first post. Two wooden logs (2) form horizontal wall sections bridging the space between the two posts when the wall structure is assembled. To assemble the joint, each log (2) is joined by a separate tie member or key (3) to the post (1). An identical joint (not shown) is envisaged between the second post and each log. The post (1) comprises an elongate longitudinal channel (4) cut along the centre of one of its four long faces (5). The channel has a T' shaped cross section, perpendicular to the plane of the face of the post, such that an undercut channel is formed in the post.

Each log has an end face formed with a vertical undercut channel (15), of identical cross section to the channel (4) in the post (1), cut into the face of an end of the log which is intended to be joined with the post.

The key (3) is an elongate section of plastics material having a generally I' shaped cross section, as shown more clearly in figure 2A. The logs (2) and the key (3) will be described in more detail below.

The key is a unitary member manufactured from injection moulded polypropylene co-polymer. The length of the key is equal to, or slightly less than, the height of the log with which it is intended to be used, less the protrusions (16) on the upper surface of the log (see figure 4). The upper and lower horizontals of the I' are formed by two opposing flanges (9). These flanges are connected by a rigid bridging web (10). Five recesses (11) of a radiused square cross section are disposed on a first face (12) of this bridging portion. These reduce the volume of injected plastics material needed in moulding the key. The opposite second face (13) of the bridging portion (which does not include the recesses (11)) is * * planar.

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* **S** * S The flanges (9), each have a flat outer surface (30) and two inward facing underside shoulder portions (31) separated by the web. The flanges have a leading end region (14). The shoulder portions at the leading end region taper so that a separation between the respective flange undersides flares towards the leading end of the flange. Thus the leading edge surfaces of the shoulder portions are each formed with feed ramps (24).

The T' cross section of the channel (15) in the end of a log (2) is shown in the transverse log section shown in figure 3. The undercut defines a shoulder surface 22 on each side of the channel which faces away from the end 19 of the log. The channel has a base wall 36 and neck walls 37.

In figure 4, a cross section of a log (2) is shown. The log has a generally oblong cross-section, with gently curved upper and lower tapering side regions, as shown in the figure. Along the upper surface (34) of the log, there are disposed two longitudinal protrusions (16) which extend along the entire length of the log.

Each log also has two longitudinal recesses (17) of square shaped cross section disposed in its lower surface 35. These also extend along the entire length of the log. The protrusions (16) are of square cross section and are adapted to cooperate with square recesses (17) on a second log when a second joint assembly is stacked on top of a first joint assembly. The protrusions and recess have a tolerance which provides an interference fit. The intimate cooperation of the pair of recesses (17) with the pair of protrusions (16) ensures that a weatherproof seal is formed between two logs of a wall section.

Figure 5 shows an alternative configuration of the post. In embodiments of the invention where the post forms a corner of a building, a second channel (18) is formed on a face of the post adjacent to the face containing the first elongate channel (4). This allows two stacks of logs to be joined, wherein the logs (not shown) of each set of joint assemblies extend perpendicularly from the post *:° (2) forming a corner.

In constructing a log cabin in accordance with the invention the °. : 20 upstanding post (1) shown in figure 1 is secured vertically into the * foundations or substrate (not shown) upon which the cabin is to be built. A first log (2) in the stack is laid end-on to the face (5) * of the post, so that the respective channels (4) and (15) are S: aligned vertically to form an I-section cavity. A front end of key * S* * 25 (3) is slid and driven, with the leading end regions first, downwardly into the upper end of channels (4) and (15).

The feed ramps 24 engage on one side of the key with the shoulder surfaces (22) (see figure 3) of the log. At the opposite side of the key the feed ramps engage with the shoulder surfaces (23) of the post's undercut channel (see figure 5). As the key is fed into the cavity the feed ramps draw the log and post together into intimate contact at their facing surfaces (since the post is fixed the log and tie both shift towards the post). Once the un-tapered portion of the flange surfaces 31 enters the cavity defined by the opposed undercut channels the key serves to maintain the log pressed to the post, with the web under tension. The tension is provided by sizing of the undercut channels and key so that the separation between flange underside surfaces (31) is marginally less than the distance between respective shoulder surfaces (23) of the log channel on the one hand and the post channel on the other.

Over time the wood may relax somewhat to reduce the web tension but an intimate contact will remain, proving a weather proof seal.

After a first joint has been assembled by the driving of the key home to intimately join a post and a first log, a small bead of silicone sealant is placed atop the first key. The joint assembly process is repeated to join further logs to the post above the first log to create a vertically upstanding wall. On addition of a further log, the silicone sealant atop the first key is compressed by the next key in the stack and forms a weatherproof joint between the separate key connectors joining the lower and upper logs to the post. The smooth planar face (13) of the key forms a weather block or seal with the internal faces of the channels (15, 4).

In summary, The invention relates to the field of construction of buildings such as log cabins. The invention relates in particular to a joint between two construction members such as a beam and a post.

0. . . * * * 20 According to one aspect of the invention there is provided a joint * I. for use in constructing buildings which serves to retain one construction member in abutment with another construction member, wherein opposing abutted faces of the construction members are each provided with an elongate undercut slot, each of which slots is co-aligned to form a cavity extending between the undercut of one face and the undercut of the other face, wherein a tie member is accommodated in the cavity, the tie member having first and second opposite side regions which occupy undercut regions of the respective slots, with a neck region extending between the opposite side regions so as to tie one construction member to the other.

According to another aspect of the invention there is provided a method of joining one construction member to another in constructing a building comprising which involves inserting a tie member into opposing undercut slots in two abutted construction members. A spacing between the opposite side regions of the tie member permitted by the neck region thereof should be marginally less than dimensionally required so that the neck region is maintained under tension with the tie member side regions engaged with the said undercut regions of the slots. In a preferred arrangement the tie member is provided with a feed ramp to ease entry of the tie member into the cavity defined by the aligned slots and draw the abutted faces together.

* *. * ** * * * ***** * S ** S * S * S. t I * * I * a.

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Claims

Claims 1. A joint for use in constructing buildings which serves to retain one construction member in abutment with another construction member, wherein opposing abutted faces of the construction members are each provided with an elongate undercut slot, each of which slots is co-aligned to form a cavity extending between the undercut of one face and the undercut of the other face, wherein a tie member is accommodated in the cavity, the tie member having first and second opposite side regions which occupy undercut regions of the respective slots, with a neck region extending between the opposite side regions so as to tie one construction member to the other.
2. A method of joining one construction member to another in constructing a building comprising: providing first and second construction members each having a face formed with an elongate undercut slot, abutting the faces and aligning the facing slots so as to form * a unitary elongate cavity comprising the two undercut slots, providing a tie member having first and second opposite side ** . regions which are configured to occupy undercut regions of the respective slots, with a neck region extending between the opposite side regions, and engaging the tie member into the cavity so that the first and second side regions occupy the respective undercut regions so as to tie one construction member to the other.
3. A joint or method as claimed in claim 1 or claim 2 wherein a spacing between the opposite side regions of the tie member permitted by the neck region thereof is marginally less than dimensionally required so that the neck region is maintained under tension with the tie member side regions engaged with the said undercut regions of the slots.
4. A joint or method as claimed in any preceding claim wherein at least one end of each slot, and preferably both ends of each slot, is/are open-ended to permit sliding engagement of the tie member along the slot to form the joint.
5. A joint or method as claimed in any of the preceding claims wherein one slot has a T-section or both slots have a T-section configuration.
6. A joint or method as claimed in any of the preceding claims wherein the tie member has a generally I-section configuration.
7. A joint or method as claimed in any of the preceding claims wherein the tie member is elongate along the slot direction and has a front end region and a rear end region, with the side regions extending between the front and rear end regions.
8. A joint or method as claimed in any of the preceding claims wherein each of the opposite first and second side regions of the tie member comprises at least one shoulder portion which defines an inward facing surface in contact with the undercut region of the slot which it occupies.°.
9. A joint or method as claimed in claim 8 wherein a feed ramp is

Sprovided which acts between a leading edge of each shoulder portion inward facing surface and a corresponding outward facing surface of the undercut region of the slot, thereby to ease entry of the tie member into the cavity defined by the aligned slots and draw the abutted faces together.
10. A joint or method as claimed in claim 9 wherein the feed ramp is provided in the leading edge of the shoulder portion inward facing surface.
11. A joint or method as claimed in claim 9 wherein the tie member has a generally I-section configuration so that there are two shoulder regions and two corresponding feed ramps at the tie member leading edge disposed side-by-side.
12. A joint or method as claimed in claim 10 or claim 11 wherein a rear end region of the tie is also provided with counterpart feed ramp or ramps so that the tie member may be slid into the slot with either the front end or rear end leading.
13. A joint or method as claimed in any of the preceding claims wherein the tie member is of unitary construction, preferably of metal or plastics material.
14. A joint or method as claimed in any of the preceding claims wherein the tie member is elongate and the neck region of the tie member is provided with a series of longitudinally spaced surface depressions which reduce the area of the tie available for contact with the slot walls.
15. A joint or method as claimed in any of the preceding claims wherein at least one construction member is a beam.
16. A joint or method as claimed in any of the preceding claims wherein one of the construction members is a post.II.....

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17. A joint or method as claimed in any of the preceding claims * . wherein one construction member is a post with an elongate * longitudinal slot formed therein and the other is a beam having an end face with an elongate slot formed therein so that the end face of the beam is joined to a side face of the post.
18. A joint or method as claimed in any of the preceding claims wherein the building is a log cabin and one or both of said construction members are formed of wood.
19. A joint or method as claimed in any of the preceding claims wherein the tie member has a length which is the same as, or slightly less than, the depth of a construction member measured in the direction of the channel length, so that one tie member is used to join each such construction member.
20. A joint or method as claimed in claim 19 wherein a plurality of construction members are joined together by the tie members and a proportion of the construction members are stacked one on top of the other, wherein a seal or beading is disposed between tie members which are themselves stacked on top of each other, thereby to weather proof the stacked joints.
21. A log cabin comprising a joint as claimed in any of claims 1 or 3 to 20. * SSS..... * S S. * * S* * ** *5 S * S S * **S *.*AMENDMENTS TO THE CLAIMS HAVE BEEN FILED AS FOLLOWSClaims 1. A joint for use in constructing buildings which serves to retain one construction member in abutment with another construction member, wherein opposing abutted faces of the construction members are each provided with an elongate undercut slot, each of which slots is co-aligned to form a cavity extending between the undercut of one face and the undercut of the other face, wherein a tie member having a generally I-section configuration is accommodated in the cavity, the tie member having first and second opposite side regions which occupy undercut regions of the respective slots, with a neck region extending between the opposite side regions so as to tie one construction member to the other, and each of the opposite first and second side regions of the tie member comprises two shoulder portions which each define an inward facing surface in contact with the undercut region of the slot which it occupies, and wherein a feed ramp is provided which acts between a leading edge of each shoulder portion inward facing surface and a corresponding outward facing surface of the undercut region of the slot, thereby to ease entry of the tie member into the cavity defined by the aligned slots and draw the abutted faces together.2. A method of joining one construction member to another in constructing a building comprising: S. S providing first and second construction members each having a * S. S S. * face formed with an elongate undercut slot, abutting the faces and aligning the facing slots so as to form a unitary elongate cavity comprising the two undercut slots, providing a tie member having a generally I-section configuration having first and second opposite side regions which are configured to occupy undercut regions of the respective slots, with a neck region extending between the opposite side regions, and engaging the tie member into the cavity so that the first and second side regions occupy the respective undercut regions so as to tie one construction member to the other, wherein each of the opposite first and second side regions of the tie member comprises two shoulder portions which each define an inward facing surface in contact with the undercut region of the slot which it occupies, and wherein two feed ramps are provided which each act between a leading edge of each shoulder portion inward facing surface and a corresponding outward facing surface of the undercut region of the slot, thereby to ease entry of the tie member into the cavity defined by the aligned slots and draw the abutted faces together.3. A joint or method as claimed in claim 1 or claim 2 wherein a spacing between the opposite side regions of the tie member permitted by the neck region thereof is marginally less than dimensionally required so that the neck region is maintained under tension with the tie member side regions engaged with the said undercut regions of the slots.4. A joint or method as claimed in any preceding claim wherein at least one end of each slot1 and preferably both ends of each slot, is/are open-ended to permit sliding engagement of the tie member along the slot to form the joint.5. A joint or method as claimed in any of the preceding claims wherein one slot has a T-section or both slots have a T-section 0 S configuration.S010S55 * 6. A joint or method as claimed in any of the preceding claims wherein the feed ramp has a profile which is linearly tapered or curved or rounded..:. : A joint or method as claimed in any of the preceding claims * wherein the tie member is elongate along the slot direction and has a front end region and a rear end region, with the side regions extending between the front and rear end regions.8. A joint or method as claimed in any of the preceding claims wherein each feed ramp is provided in the leading edge of each shoulder portion inward facing surface.9. A joint or method as claimed in claim 8 there are two shoulder regions and two corresponding feed ramps at the tie member leading edge disposed side-by-side.10. A joint or method as claimed in claim B or claim 9 wherein a rear end region of the tie is also provided with counterpart feed ramp or ramps so that the tie member may be slid into the slot with either the front end or rear end leading.11. A joint or method as claimed in any of the preceding claims wherein the tie member is of unitary construction, preferably of metal or plastics material.12. A joint or method as claimed in any of the preceding claims wherein the tie member is elongate and the neck region of the tie member is provided with a series of longitudinally spaced surface depressions which reduce the area of the tie available for contact with the slot walls.13. A joint or method as claimed in any of the preceding claims wherein at least one construction member is a beam.14. A joint or method as claimed in any of the preceding claims wherein one of the construction members is a post.15. A joint or method as claimed in any of the preceding claims S. S wherein one construction member is a post with an elongate *:" longitudinal slot formed therein and the other is a beam having an end face with an elongate slot formed therein so that the end face .: of the beam is joined to a side face of the post.16. A joint or method as claimed in any of the preceding claims wherein the building is a log cabin and one or both of said construction members are formed of wood.17. A joint or method as claimed in any of the preceding claims wherein the tie member has a length which is the same as, or slightly less than, the depth of a construction member measured in the direction of the channel length, so that one tie member is used to join each such construction member.18. A joint or method as claimed in claim 17 wherein a plurality of construction members are joined together by the tie members and a proportion of the construction members are stacked one on top of the other, wherein a seal or beading is disposed between tie members which are themselves stacked on top of each other, thereby to weather proof the stacked joints.19. A log cabin comprising a joint as claimed in any of claims 1 or 3 to 20.20. A tie member substantially as hereinbefore described with reference to figures 2A, 2B and 2C of the drawings.S * t S * S.S * I S. S * I SI II S5 1 S 55SI