GB2305629A

GB2305629A - A process for producing a timber construction panel

Info

Publication number: GB2305629A
Application number: GB9519721A
Authority: GB
Inventors: Peter Mccaughey; Sean Mccaughey; Martin Mccaughey
Original assignee: Maca R & D Ltd
Current assignee: Maca R & D Ltd
Priority date: 1995-09-22
Filing date: 1995-09-27
Publication date: 1997-04-16
Anticipated expiration: 2015-09-27
Also published as: GB2305629B; IES950740A2; GB9519721D0; IES66579B2

Abstract

The panel 1 has a framework sandwiched between cladding sheets 2. A conveyor 10 has a releasable clamp provided by a pair of oppositely directed jaws 11 to clamping a workpiece 12 and to move the workpiece 12 through a workstation 14 in response to assembly signals. The workstation 14 has stop bars and clamping feet which are pivoted in response to assembly signals to releaseably engage the workpiece to allow the framework to be added. Sensors sense the correct insertion of struts and struts are fastened together using nails from nailing hammers 23 before the conveyor 10 moves the workpiece 12 to the next assembly position.

Description

"A process for producing a timber construction panel" The present invention relates to a timber construction panel and more particularly to the production of a timber construction panel of the type having a framework sandwiched between cladding sheets.

Currently timber construction panels are produced using a variety of adjustable jigs. The jigs are setup to receive struts in the appropriate locations and pieces are inserted and nailed. This method is suitable when producing a large number of identical panels, however it presents a significant problem to manufacturers who are required to produce a wide variety of construction panels. The physical problem of reconfiguring the assembly jigs requires skilled personnel to ensure that jigs are correctly aligned and can result in significant production lead times.

It is an object of the invention to provide a process for producing a high quality and robust timber construction panel in an efficient manner while minimising production costs. It is a further objective to produce the panel with a minimum of waste timber and optimising stock utilisation.

According to the invention there is provided a process for producing a timber construction panel of the type having a framework sandwiched between cladding sheets, the framework being formed by four connected peripheral frame members namely, horizontal top and bottom frame members a leading vertical frame member and a trailing vertical side frame member, and a plurality of internal struts, the process comprising the sequential steps, on a conveyor having a releasable clamp for clamping a workpiece and moving the workpiece through a workstation, said workstation having a plurality of guides, sensors, clamps, fasteners and cutting means, of:: securing the leading side frame member in a guide, releasing a clamp means adjacent the guide, inserting the top frame member and the bottom frame member into the guide so that the top frame member and the bottom frame members are perpendicular to and at opposed ends of the leading side frame member, sensing the correct insertion of the leading side frame member, the top frame member and the bottom frame member, clamping the top and bottom frame members in the correct relative position to the workstation, fastening the leading side frame member, the top frame member and the bottom frame member together to form the workpiece, gripping the workpiece to secure the work piece to the conveyor and releasing the guide and clamp, incrementally moving the conveyor to deliver the workpiece to a number of workpositions in sequence, at each workposition performing the steps of, inserting a strut into the guide, sensing the correct insertion of the strut, clamping the workpiece to the workstation, fastening the strut in position on the workpiece and releasing the guide and clamp.

The process significantly reduces lead times as the time taken by skilled personnel to realign the jigs is eliminated. Additionally as the conveyor moves the workpiece, errors resulting from incorrect jig alignment or movement of the jig during production of the panel are eliminated. This reduces the production cost of the panel by eliminating wastage of materials and assembly components.

Preferably the process includes the steps of: clamping the workpiece in position on the workstation, engaging the cutting means to cut away extending portions of the horizontal frame members prior to the insertion of at least one horizontal frame member extension, loading one or more connector plates into at least one clamp hammer pivotally mounted on the workstation, inserting the frame member extension so that the horizontal frame member and the frame member extension abut end to end, sensing the correct insertion of the frame member extension, and pivoting and closing the clamp hammer to fasten the bottom frame member and the bottom frame member extension relatively.

This allows for the production of a construction panel of greater physical size to be produced. Advantageously allowing smaller production facilities to produce larger construction panels by using frame member extensions effectively removing jig size as a physical limit.

Preferably the process includes the steps of: inserting the trailing side frame member in the guide, sensing the correct insertion of the trailing side frame member, clamping the workpiece to the workstation, securing the trailing side frame member in position on the workpiece releasing the guide and clamp disengaging the workpiece from the conveyor, and delivering the workpiece to a cladding station. In this way the construction panel is accurately finished reducing errors.

Ideally the process includes the steps of: covering the workpiece with a cladding layer, securing the cladding layer in position on the workpiece to produce a clad panel, and delivering the clad panel to an output station.

Preferably the process includes the step of covering the clad panel with a breather membrane.

In a preferred arrangement the process comprises the steps of: generating a workpiece control list for the construction panel to generate an initialisation signal and a plurality of assembly signals for transmission to the workstation, for controlling the guides, sensors, clamps, fasteners and cutting means.

In this way, production lead times are significantly reduced by using the initialisation signal and the assembly signals to control assembly of the panel effectively reconfiguring the jig in real time.

Additionally as the sequence and nature of the assembly signals may be easily altered the flexibility of the system is significantly improved.

Ideally the process includes the steps of: receiving raw timber pieces, machining and treating the raw timber pieces, receiving the assembly signals, and cutting the framework struts to a desirable size and shape in response to the received assembly signals.

Thus, optimimum use is made of raw materials in that a minimum is lost during the cutting process.

Advantageously, just in time delivery is also possible reducing storage requirements for the process and ensuring an adequate supply of appropriate component parts.

Ideally the step of generating the workpiece control list comprises the steps of: defining a length and a breath dimension for each panel, relative to a panel bottom, retrieving a pre-defined library of standard panel types, selecting a panel type from the library to define a height and structure panel characteristic, generating a framework information list for the panel characteristic, and validating the panel characteristic against a structural integrity library. Thus, the control list may be produced by relatively inexperienced personnel requiring minimal component selection details.

Preferably the process includes the steps of: defining at least one panel aperture position and an aperture size relative to the panel bottom, retrieving a pre-defined aperture library of standard aperture types, and selecting an aperture type for each aperture in turn from the aperture library.

According to one aspect of the invention there is provided a timber construction panel whenever produced by the process.

According to another aspect of the invention there is provided a timber frame building whenever produced by the process as claimed in any preceding claim.

The invention will be more clearly understood from the following description thereof, given by way of example only with reference to the accompanying drawings in which: Fig. 1 is partially cut-away perspective view of a timber construction panel produced in accordance with the invention; Fig. 2 is a diagrammatic view illustrating a timber construction panel production plant for use in the process according to the invention; Fig. 3 is a diagrammatic view of a conveyor and workstation used in the process; Fig. 4 is a diagrammatic view of the conveyor and workstation of Fig. 3 showing a partially completed workpiece; Figs. 5 and 6 are cut-away perspective views showing the operation of a guide forming part of the workstation of Figs. 3 and 4 Figs. 7 and 8 are cut-away perspective views similar to Fig. 4 showing further details of the workstation;; Fig. 9 is a cut-away perspective view showing the operation of a circular saw forming part of the panel assembly unit; Figs. 10 and 11 are partially cut-away perspective views showing the operation of a clamp hammer forming part of the panel assembly unit; Fig. 12 is a perspective view of a horizontal frame member and a horizontal frame member extension secured relatively; and Fig. 13 is a schematic flow chart illustrating a process for generating a workpiece control list forming part of the invention.

Referring to the drawings and initially to Fig. 1 there is illustrated a timber construction panel produced according to the invention indicated generally by the reference numeral 1. The panel 1 has a framework sandwiched between cladding sheets 2, the framework is formed by a generally horizontal top frame member 3, a horizontal bottom frame member 4 a vertical leading side frame member 5, a vertical trailing side frame member 6 and a number of internal struts 7. The terms horizontal and vertical refer to the general in use position of the frame members.

Referring now briefly to Fig. 2 there is shown a timber construction panel production plant indicated generally by the reference numeral 30 for use in the process in accordance with the invention. The production plant 30 has a pre-fabrication station indicated generally at 50, two workstations 14, two cladding stations 60 and an output station 70.

Referring now to Figs. 3 and 4 there is illustrated a conveyor 10 having a releasable clamp provided by a pair of oppositely directed jaws 11 for clamping a workpiece 12 and moving the workpiece 12 through the workstation 14.

In more detail and referring now to Figs. 5 to 11 the workstation 14 has two guides provided by a pair of stop bars 21 pivotally movable between a disengaged position (see Fig. 5) and an engaged position (see Fig. 6). The workstation 14 has six optical sensors (not shown) and four clamps provided by identical clamping feet 22, each clamping foot 22 being pivotally and slidably movable between an in use clamped position (see Fig. 8) and a inoperative position (see Fig. 7). The workstation 14 also has fasteners provided by four pneumatic nailing hammers 23 and a pivotally movable clamping hammer 24 with moveable jaws 29 and a cutting means furnished in this case by a pivotally movable circular saw 25.

Raw timber 31 is received at the pre-fabrication station 50 and is machined treated and cut to produce frame members 3, 4, 5 and 6 and internal struts 7 of a desirable size and shape. These all form a timber component supply 32. The cutting and shaping of the supply 32 is dynamically controlled in response to the type of construction panel being produced ensuring that the frame members and internal struts are correctly cut and delivered in the correct sequence to the workstation 14.

The process according to the invention is described below for the production of the panel 1.

At the workstation 14 the stop bars 21 are first pivoted in the direction of the arrow X from the disengaged position to the engaged position and the leading side frame member 5 is secured against the stop bars 21.

The clamping feet 22 are moved in the direction of the arrows Y and Z to the inoperative position and the top frame member 3 and the bottom frame member 4 are then inserted perpendicular to and at opposite ends of the leading side frame member 5.

When the sensors sense the correct insertion of the leading side frame member 5 and the horizontal side frame members the clamping feet 22 are activated and moved to the clamping position, securely clamping the top and bottom frame members relative to the workstation 14.

Once clamped, the leading side frame member 5, the top frame member 3 and the bottom frame member 4 are fastened together using four nails (not shown) from the nailing hammers 23.

The oppositely directed jaws 11 then close together to engage the workpiece 12, the stop bars 21 are returned to the disengaged position, and the clamping feet 22 are moved to the repose position.

The workpiece 12 is moved incrementally by the conveyor 10 between a number of sequential workpositions at each of which an internal strut 7 is added. At each workposition the stop bars 21 are moved to the engaged position, the internal strut 7 is inserted against the stop bar 21, the correct insertion of the internal strut 7 is sensed, the clamping feet 22 are moved to the engaged position on the workpiece 12, and the internal strut 7 is secured in position relative to the workpiece 12 using the hammers 23. The stop bars 21 and the clamping feet 22 are then disengaged.

When all of the internal struts 7 have been mounted on the workpiece 12 the conveyor 10 moves the workpiece 12 to the final workposition, the stop bars 21 are again pivoted to the engaged position and the trailing side frame member 6 is inserted.

When it is sensed that the trailing side frame member 6 is correctly inserted the clamping feet 22 are engaged to clamp the workpiece 12 on the workstation 14 and the trailing side frame member 6 is secured in position using the hammers 23 on the workpiece 12.

The stop bars 21 and the clamping feet 22 are then disengaged and the workpiece 12 is delivered to the cladding station 60.

At the cladding station 60 the workpiece 12 is covered with the cladding layer 61 of plywood which is secured in position on the workpiece using nails to produce a clad panel 62. The clad panel 62 is then delivered to the output station 70. At the output station 70 the clad panel 62 is covered with a breather membrane.

When the horizontal frame members are too long to be manufactured conveniently from the one length of timber the clamping feet 22 are engaged on the workpiece 12 and the circular saws 31 are pivoted upwards to an engaged position (see interrupted lines Fig. 9) to cut away any excess portion of the horizontal frame members. Two connector plates 26 are then loaded into the jaws 29 of both clamp hammers 24 and two horizontal frame member extensions 27 are inserted so that each extension and the corresponding horizontal frame member abut end to end. When correctly inserted the clamp hammer 24 is pivoted from a disengaged position (see Fig. 10) to an engaged position (see Fig. 11) surrounding the abutting edges of the horizontal frame members and frame member extensions 27. The hammer jaws 29 are then forced closed to fasten the horizontal frame members and frame member extensions 27 relatively (see Fig. 12).

Referring now to Fig. 11 there is illustrated a schematic flow chart of a process for generating a workpiece control list indicated generally by the reference numeral 100. The workpiece control list 100 is used to generate an initialisation signal and a plurality of assembly signals for transmission to the workstation 14 to control the stop bars 21, the clamping feet 22, the conveyor 10, the jaws 29, the means for sensing the correct placement of frame members, the pneumatic hammers 23 and the clamp hammer 24. The workpiece control list 100 is also used to control machining, treating and cutting raw timber pieces to a desirable size and shape. To ensure optimum use of materials and to guarantee the correct sequenced delivery of component timber struts.The work control list 100 and the associated signals may be transmitted using any suitable transmission medium such as a computer network. Such a computer network may also allow reception of error or pause signals from the production process to pause or cease generation of further assembly signals. This significantly enhances the overall flexibility of the production process as the signals generated may be in any order and may be amended in real time. Further as the signals may be interrupted a single error in production does not cause the loss of an entire panel. This in turn reduces the production cost of the panel by ensuring that minimal components such as connector plates are lost due to errors in production.

A length and a breath dimension for each panel relative to a panel bottom is defined and stored at step 101. A pre-defined library of standard panel types is then retrieved at step 102, a panel type is then selected from the library to define a height and structure panel characteristic 103. In step 104 a framework information list containing all the peripheral frame and internal strut interconnections is automatically generated for the panel 2 and passed to a validation stage 105 where it is validated against a structural integrity library prior to generating the initialisation signal and the assembly signals.

There are many advantages with the present process. For example, it will be appreciated that the extension of horizontal frame members in this way allows for the construction of panels of great length.

It will also be appreciated that construction panels of different depth and load bearing capability may be produced. Using a combination of a variety of these panels in applications such as floors, walls, roofs or ceilings allows for the construction of a wide variety of structures. Additionally the panels may be easily be provided with necessary apertures by altering the structure of the cladding and associated internal struts to accommodate the fitting of doors, windows or stairwells. In addition to the advantages of reducing timber wastage and guaranteeing delivery of correctly sequenced components, the workpiece control list 100, also allows structural validation to be done for the building as a whole by compiling validated panel lists of adjacent panels.

It will be noted that the automatic generation of the initialisation and assembly signals significantly reduces the time required to specify each timber construction panel for assembly. Further as the initialisation and assembly signals may also be used to machine the raw timber pieces optimum material ordering is ensured minimising storage time and allowing just in time stock management techniques to be used.

It will be appreciated that the process described above may equally be applied to the construction of A-frame rafters for supporting roofs.

It will also be appreciated that a number of battens may be fixed to the panel to provide a services core and that the panel may be provided with a plasterboard cladding.

The panel may also be produced with an insulating material and an optional vapour barrier.

The invention is not limited to the embodiment hereinbefore described, which may be varied in both construction and detail.

Claims

1. A process for producing a timber construction panel of the type having a framework sandwiched between cladding sheets, the framework being formed by four connected peripheral frame members namely, horizontal top and bottom frame members a leading vertical sideframe member and a trailing vertical side frame member, and a plurality of internal struts, the process comprising the sequential steps, on a conveyor having a releasable clamp for clamping a workpiece and moving the workpiece through a workstation, said workstation having a plurality of guides, sensors, clamps, fasteners and cutting means, of:: securing the leading side frame member in a guide, releasing a clamp means adjacent the guide, inserting the top frame member and the bottom frame member into the guide so that the top frame member and the bottom frame members are perpendicular to and at opposed ends of the leading side frame member, sensing the correct insertion of the leading side frame member, the top frame member and the bottom frame member, clamping the top and bottom frame members in the correct position relative to the workstation, fastening the leading side frame member, the top frame member and the bottom frame member together to form the workpiece, gripping the workpiece to secure the work piece to the conveyor and releasing the guide and clamp, incrementally moving the conveyor to deliver the workpiece to a number of workpositions in sequence, at each workposition performing the steps of, inserting a strut into the guide, sensing the correct insertion of the strut, clamping the workpiece to the workstation, fastening the strut in position on the workpiece and releasing the guide and clamp.

2. A process as claimed in claim 1 including the steps of: clamping the workpiece in position on the workstation, engaging the cutting means to cut away extending portions of the horizontal frame members prior to the insertion of at least one horizontal frame member extension, loading one or more connector plates into at least one clamp hammer pivotally mounted on the workstation, inserting the frame member extension so that the horizontal frame member and the frame member extension abut end to end, sensing the correct insertion of the frame member extension, and pivoting and closing the clamp hammer to fasten the bottom frame member and the bottom frame member extension relatively.

3. A process as claimed in claim 1 or claim 2 including the steps of: inserting the trailing side frame member in the guide, sensing the correct insertion of the trailing side frame member, clamping the workpiece to the workstation, securing the trailing side frame member in position on the workpiece releasing the guide and clamp disengaging the workpiece from the conveyor, and delivering the workpiece to a cladding station.

4. A process as claimed in any preceding claim including the steps of: covering the workpiece with a cladding layer, securing the cladding layer in position on the workpiece to produce a clad panel, and delivering the clad panel to an output station.

5. A process as claimed in claim 4 including the step of covering the clad panel with a breather membrane.

6. A process as claimed in any preceding claim comprising the steps of: generating a workpiece control list for the construction panel to generate an initialisation signal and a plurality of assembly signals for transmission to the workstation, for controlling the guides, sensors, clamps, fasteners and cutting means.

7. A process as claimed in claim 6 including the steps of: receiving raw timber pieces, machining and treating the raw timber pieces, receiving the assembly signals, and cutting the framework struts to a desirable size and shape in response to the received assembly signals.

8. A process as claimed in claims 6 or 7 in which the step of generating the workpiece control list comprises the steps of: defining a length and a breath dimension for each panel, relative to a panel bottom, retrieving a pre-defined library of standard panel types, selecting a panel type from the library to define a height and structure panel characteristic, generating a framework information list for the panel characteristic, and validating the panel characteristic against a structural integrity library.

9. A process as claimed in claim 8 including the steps of: defining at least one panel aperture position and an aperture size relative to the panel bottom, retrieving a pre-defined aperture library of standard aperture types, and selecting an aperture type for each aperture in turn from the aperture library

10. A process for producing a timber construction panel substantially as hereinbefore described with reference to the accompanying drawings.

11. A timber construction panel whenever produced by the process as claimed in any preceding claim.

12. A process for producing a timber frame building utilising a timber construction panel substantially as hereinbefore described with reference to the accompanying drawings.

13. A timber frame building whenever produced by the process as claimed in any preceding claim.