AU592676B2 - Roofing protractor - Google Patents

Description

5926 0/76 Form PATENTS ACT 1932-1 973 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Class:- Int. CI: Application Number: Lodged: *Complete Specification-Lodged: Accepted: Published:, Priority I i nis document contains tie' aimendments alade uinder Section 49 and is c'oti~xt for printing, Related Art: Name of Applicant: Address of Applicant: TO BE COMPLETED BY V, RA4AT I CAK No, 6S, HT.)wir ALt)PU~fY $L-ST

APPLICANT

5.A. frs 1-l"L A IZE W \,?ALE Actual Inventor: T<1I C1AP-L Q WA-11 L-''AtC Address. for Service: A SbVE Complete Speatflcation for the Invention entitled:, RF1Fr4, C4 P#OTOZ^CITO iF The following statement Is a full description of this invention, Including the best method of performll% It known to me:.- 'Note; The description is to be typed In double spacing, pica type loce, In an atop not exceeding 250 mm In depth and 160 mm in width, on tough white paper of good qualityi and It Is to be Inserted Inside this form., I 1? 110/18.1. 1 flIO/704, (C 3. TgwHI'I, orninweatih aoiwenmnj I'inier, tCinberr,

PREAMBLE

The invention is a roofing protractor used to find, measure and mark angles between 00 and Although it may be used by a wide range of persons employed in a variety of industries, it is particuarly suitable for the measuring and marking of angles for cutting and fitting together the various components in roof construction.

Roofing Carpenters would find the instrument time saving and effective where they, by preference or training, use math- .0 ematics to solve the angles for roof members.

The instrument provides the link between the pocket calculator and the marking of the work piece.

*t t i th t Rofn apneswudfn teisrmn iesvn n DESCRIPTION OF THE INVENTION: The roofing protractor is a hand held instrument comprising A two basic parts and attachments.

Part A indicated on the accompanying drawing and shown in Figs 1 2 consists of a stock 370mm long x 50mm wide and folded to give an ove.rall thickness of 22mm.

The stock is made from opaque white thermoset plastic 4mm thick and moulded at 2 intervals along its length to provide stiffness and support for Part B. The quadrant. The shape position of moulded bends and curves are seen in Fig 2.

The top end of the stock, (as the instrument is held and read) is folded upon itself and contains as a pivot, a 12mm x 6mm diameter bolt and wing nut. The concentric centre of the quadrant will pivot about this fastening.

The lower end of the stock is again folded upon itself and terminates on a line with the calibrated degrees on the quadrant. The stock at this position its also calibrated in S, 05 division to act as a vernier scale.

The stock is also fitted with a 6mm diameter bolt and wing SQ 0 nut together with a clamping assembly in order to secure the t instrument at the selected angle.

The quadrant, Part B, consists of a flat polyvynilchloride quarter circular plate with sides 250mm long and is 3mm thick.

S Calibrated along its arc are 5° intervals from 0° to 90°. The quadrant is attached to the stock by bolt and wing nut previously mentioned, in such a way as to allow the quadrant to pivot and pass through the sto k The materials chosen for the manufacture of the instrument are those recommended by the manufacturer.

d0 The calibrations and all othex figures and letters are to be installed using a hot press method for durability and will be black for easy reading.

2

I

THE FIELD OF THE INVENTION There are currently a number of different methods, tools, instruments and the like, in use by the roofing carpenter (and other persons doing like or similar work) which can successfully be used to carry out structurally that which is intended in the design.

I Some tradespersons may have preference for setting out the job full size, on site, using actual roofing members.

Obviously the main disadvantage in this method slowness, a step by step process and difficult to apply to prefabrication.

Others may prefer developmental geometry to arrive at scaled versions of angles and bevels required to mark and cut roofing members. This method is effective but requires returning to the drawing board which may not be practical and requires a reasonable amount of skill training in technical drawing.

THE OBJECTS OF THE INVENTION The present training in ths use of pocket calculators for all manner of work situations has provided people entering S the industry with a method or medium that has familiarity.

The lengths and bevels for the members contained in a roof can be found mathematically using relatively simple trigonometric function, given only the span and the pitch angle of roof.

A

THE METHOD OF CARRYING OUT THE INVENTION: The average framed timber roof with hipped ends contains eleven separate bevels at which -the timber is required to be cut. Roofs of unequal pitch or off-square corners will multiply the number of bevels required.

Roofs may be pitched at any angle provided they meet the minimum standard pitch requirement for the covering material being used.

The pitch angle can be read on the roofing protractor for example 22.5' by locating the 22.50 using both the calibrations on the quadrant part B. Fig 1. and -the stock Part A. Fig 1.

and locking in position -the result provides for the "Plumbcut" on one side of the instrument and the "Seat-cut" on the opposing side.

By holding the stock against the timebr appropriately these cuts can be marked, in -this case, for the common rafter.

All other angles, for each off the roof members can be arrived at mathematically and trigonometrically.

The ofing protractor conveys the varimus angles to the It 4 s workpiece direct.

A users manual will be incorporated in packaging to instruct and guide the user in the appropriate manner. It will contain formulae and tables, and other suggested uses of the invention.

4.'4-

Claims (1)

1. 4. 4 44* *4 4 S C 9# CLAIM 1: A roofing protractor, which is a hand held instrumrent of two major components, a) a stock passing beneath a quadrant and folded back upon itself and the quadrant so that the end of the stock overlaps the curved edge of the quadrant, and b) a quadrant pivoted at its apex to the other end of the stock byr means of an adjustable bolt and wing nut, the curved edge of the quadrant being calibrated in degrees and being aligned with a vernier scale on the adjacent portion of the stock, and being able to be locked at the selected angle. 20/nik( 108) LI I 1. 1 .1 D ted 111 a1- ~~~NAM OF.. f. .p c ab. .yp .t.....fcamd o u e ti he t u u e s p ra s e bein.n with th ords... The. claim. def..ning in.n.o fo.o- and... .ndngwit.te.dtaandth na. the. .pc n n bl...ck. j:1