GB2207518A

GB2207518A - Protractor device

Info

Publication number: GB2207518A
Application number: GB08717466A
Authority: GB
Inventors: James Walter Sydney Bick
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-07-23
Filing date: 1987-07-23
Publication date: 1989-02-01
Also published as: GB8717466D0

Abstract

A protractor device for use in estimating roof sizes, and as a consequence the amount of materials required and the associated costs involved, comprising reference means ( theta 1 to theta 7) which, when the device is located in a line-of-sight between a user and the end of a pitch roof, is capable of being brought into register with the edges of the roof end, to provide a value representative of the angle of pitch of the roof. The reference means, preferably in the form of at least one pair of inclined lines which may be fixed or movable, is provided upon an at least partially transparent base. Associated computing means (38,39) may be provided to receive the representative value and to calculate the desired values and costs. <IMAGE>

Description

PROTRACTOR DEVICE DESCRIPTION This invention relates to a protractor device for estimating roof sizes, quantities of roofing materials (say, roof tiles) required and the costs associated therewith.

The quantity of roof tiles required to retile a pitch roof is dependent upon three parameters, namely, the length, breadth and angle of pitch of the roof. Known methods of estimating such a quantity are either hit-and-miss or laborious or a combination of both.

One of the most common methods of estimating the number of tiles required to tile or re-tile a pitch roof is based upon the working experience of the estimator, in that he judges the angle of pitch of the roof by eye and, having measured the length and breadth of the roof, at its base, then estimates the number of tiles required on the basis of two reasonable accurate measurements, namely, the length and breadth, and one generally inaccurate parameter, namely, the roof pitch angle.

Another commonly used method of this type of estimating is to count the number of courses of tiles on an existing roof to be re-tiled. As this method generally has to be carried out at some distance from the roof, binoculars sometimes have to be used by the estimator.

It is to be appreciated that these known methods of estimating the number of tiles required for a roof are somewhat inaccurate, particularly the former, resulting in unreliable estimates which, as far as costs are concerned, result in either losses to the roofing contractor, when an estimate is too low, or the possible loss of a roofing contract when an estimate is too high.

It is an object of this invention to provide a protractor device which, when used to estimate a roofing contract, eliminates, or at least substantially reduces, the inaccuracies associated with known methods of this type of estimating.

Accordingly, the invention provides a protractor device for use in estimating roof sizes, and as a consequence the amount of materials required and the associated costs involved, which device comprises reference means which, when the device is located in a line-of-sight between a user and the end of a pitch roof, is capable of being brought into register with the edges of said roof end, to provide a value representative of the angle of pitch of the roof.

Preferably, said reference means consists of at least one pair of lines which are inclined to one another and which define therebetween an angle rep resentative of a given roof pitch angle, with the or each pair of lines being provided upon an at least partially transparent base through which a user can view the end of a pitch roof to be estimated using the device, whilst being able to bring the or the respective pair of lines into register with the roof edge, preferably at the apex thereof.

As an alternative to the preferred arrangement described above, said reference means may comprise a fixed reference line, preferably provided upon an at least partially transparent base, and a movable reference line which may be pivotable about one end of the fixed line and which, when the latter is brought into register with one side edge of a pitch roof, can be brought into register with the other side edge of the end of the roof, thereby providing a value representative of the roof pitch angle. Such value may be read from a scale associated with the movable reference line.

In a preferred embodiment of the inventive protractor device, the value, which is representative of the angle of pitch of a roof, is fed, either manually or automatically, into computing means, along with other roof parameters, such as, the length and breadth thereof, to provide an appropriate calculation as to, say, the number of roof tiles required and the costs involved in roofing or re-roofing the roof. Also, said computing means may be pre-programmed with the sizes and cost of different roof tiles, as well as associated labour costs and overheads, so that various estimates for diffenrent types and sizes of tiles can be provided.

Preferably, said computing means can be incorporated in the device, for instance, if the device has a transparent plastics base upon which the reference means are provided, the computing means can be in the form of a calculator embedded in the plastic base, with the associated operating keys exposed for manual operation.

Three preferred... forms. of protractor device in accordance with the invention will now be described by way of example and with reference to the accompanying drawings in which: Fig. 1 is a front view of a protractor device for roofing estimates; Fig. 2 is another form of roofing protractor device; Fig. 3 is a further form of roofing protractor device; and Fig. 4 is a diagrammatic view of any of the three devices of respective Figs. 1 to 3, when being used to estimate a roof.

Referring firstly to Fig. 1 of the drawings, a protractor device 1 for use in estimating roofing requirements comprises a flat, generally square base 2 of a transparent material, preferably a plastics material, on one major surface of which is scored, or otherwise marked, seven pairs of inclined lines A,A' to G,G'.

The lines A,A' to G,G' of each pair extend from respective bottom corners of the base 2 and meet at their upper ends to define an angle çI to 9 therebetween. These angles eI to 97 are respective roof apex angles of pitch roofs which, in turn, are related to the corresponding angles of pitch of the roofs. A roof pitch angle 9p can be represented by the following equation: Çp 1800 - 2 where n is 1, 2, 3, 4, 5, 6 or 7 for 20 , 30 , 35 , 40 , 45 , 50 and 60 pitch roofs, respectively.The roof pitch angle ep is, in fact, the angle defined between the sloping edge of the roof and the horizontal.

In use of the device 1, it is held up by a user standing a distance from one end of a roof 40 of a building 50, as shown in Fig. 4, so that it is located between the user's eye 49 and the roof end 48, with the appropriate pair of inclined lines A,A' to G,G' in register with the end edge of the roof and with the apex of the angle %)o defined between the two lines in register with the apex of the roof.

The user, having measured the length- and breadth of the roof 40, is now able to calculate the number of roof tiles required to re-roof the building 50, using the following equation: Ra Lr x Br x F where R is the roof area to be re-tiled, L is the length a r of the roof, Br is the breadth of the roof and F is a conversion factor dependent upon the roof pitch angle.

This factor F has been calculated for 20 , 30 , 35 , 40o, 45", 50" and 60 pitch roofs as 1.07, l.ló, 1.23, 1.30, 1.41, 1.54 and 1.94, respectively. A further factor related to the cost of the roof tiles can be included in the calculation, to determine the cost of the tiles required and a factor for tile coverage for Ra Referring now to Fig. 2 of the drawings, another embodiment of prstr bar device 21 comprises a transparent plastics, flat base 22 of generally rectangular shape.

On a major surface of the base 22 is marked a semicircular scale 23 and a fixed reference line 24. At the centre 25 of the line 24 is pivoted to the base 22 a movable reference line 26 with a pointer 27 at the free end thereof, for reading an angle X from the graduated scale 23.

Use of this device 21 is similar to that described above with reference to the embodiment shown in Fig. 1 of the drawings, except that the reference line 24 is brought into register with the edge of one side of the roof end and the other, movable reference line 26 is pivoted about 25 until it lies in register with the edge of the other side of the roof end, -such that the roof apex angle X is obtained. The calculation is then carried out to determine the number of tiles required, using the equation for R above.

a Fig. 3 shows a further embodiment of protractor device 31 which is similar to that described above in relation to Fig. 1, except that it includes computing means, in the form of a calculator which is encapsulated in the transparent plastics base 32 and which has a liquid crystal, or other suitable form of, display 39 and operating keys 38. The keys 38 marked L, B, F and C are for entering the length, breadth, conversion factor and cost of materials, respectively, the factor F being determined by the apex angle identified with the device.

The calculator can be pre-programmed to include other data necessary for estimating roofing costs as accurately as possible.

It is to be appreciated that a protractor device in accordance with the invention, as defined above, can be used for other estimating purposes, for instance, felting and slating and even thatching, whilst also providing a most useful but easy-to-use tool for roofing estimating purposes.

Also, it is to be understood that the value representative of the angle of the pitch of the roof can include an angle directly associated therewith or a parameter derived therefrom, for example, the conversion factor F.

Claims

1. A protractor device for use in estimating roof sizes, and as a consequence the amount of materials required and the associated costs involved, which device comprises reference means which, when the device is located in a line-of-sight between a user and the end of a pitch roof, is capable of being brought into register with the edges of said roof end, to provide a value representative of the angle of pitch of the roof.

2. A device according to claim 1, wherein said reference means consists of at least one pair of lines which are inclined to one another and which define therebetween an angle representative of a given roof pitch angle.

3. A device according to claim 1, wherein said reference means consists of a fixed reference line and a movable reference line which is pivotable about one end of the fixed line and which, when the latter is brought into register with one side edge of a pitch roof, can be brought into register with the other side edge of the end of the roof, thereby providing a value representative of the roof pitch angle.

4. A device according to claim 1, wherein said reference means comprises two movable lines pivotable about respective axes and capable of being brought into register with resepective side edges of a pitch roof, thereby providing a value representative of the roof pitch angle.

5. A device according to claim 4, wherein the two movable reference lines are pivotable about a common axis.

6. A device according to any preceding claim, wherein said reference means is provided upon an at least partially transparent base.

7. A device according to any preceding claim including associated computing means into which said representative value can be fed.

8. A device according to claim 7, wherein said computing means is arranged to have said represeht- ative value fed manually or directly thereinto.

9. A device according to claim 7 or 8, wherein said computing means is pre-programmed with roofing parameters and associated material costs.

10. A protractor device substantially as hereinbefore described with reference to the accompanying drawings.

11. A method of estimating roof sizes and, as a consequence, the amount of materials required and the associated costs involved, which method comprises providing a protractor device according to any preceding claim, locating the device in a lineof-sight between a user and the end of a pitch roof and bringing said reference means into register with the edges of the roof end, to provide a value representative of the angle of pitch of the roof.

12. A method of estimating roof sizes and, as a consequence, the amount of materials required and the associated costs involved, substantially as hereinbefore described with reference to the drawings.