GB2277801A - A device to establish a true perpendicular - Google Patents

Abstract

A ruler encapsulating a plumb bob suspended from a pivot located on a datum, within a transparent casing. The datum is parallel to both edges of the device, enabling alignment of the plumb with the datum to a true perpendicular and the edges of the device are vertical and may be used as a register or to mark a true perpendicular. <IMAGE>

Description

A DEVICE TO ESTABLISH A TRUE PERPENDICULAR This invention relates to a device or instrument which enables a true perpendicular to be easily and accurately established.

The device utilises the theory expounded by Isaac Newton that the force of gravity is constant. Further it derives from mathematics the principle that parallel lines remain the same distance apart, even if taken to infinity.

The invention comprises a form of ruler encapsulating a plumb with an elliptical cross section, suspended from a pivot, located on a datum, within a casing, marked parallel to the edges of the ruler enabling alignment of the plumb with the datum to a true perpendicular and by the theory of parallels the edges of the ruler are also perpendicular.

It can be produced in different formats, from various materials, to specific quality standards, progressing from general household use to application in scientific research.

Each element of its construction may be enhanced progressively, raising the specification of the end product to the level where its accuracy may be described as absolute.

The specific example of the invention described below and illustrated in the accompanying drawings is a simple unit for household / DIY use, intended to be constructed predominantly from clear plastic components.

The device comprises 4 elements as shown in Figure 1.

Details of Element 3 are given in Figures 2, 3 and 4.

Assembled the device is illustrated in Figure 5.

Application of the device is demonstrated in Figures 6 and 7.

Referring to the drawings the device comprises a backplate 1 embossed with a datum 5 parallel to its edges, and various markings 6 forming imperial and metric measurements, a protractor 7 and an angle scale 8. Blind drilled 9 as shown and drilled / counterbored as indicated 10.

A centre section 2 in part cut away, with the outer edges bevelled at 45 11 drilled through as indicated 12. This section, if produced seperately, can be permanently fixed to the backplate.

A metal plumb assembly 3 consisting of a pivot 13 with spacer washers 14, passing through a connector 15 with an elongated access 16, in part threaded at its lower end to enable its effective length to be varied, and a plumb 17 with an elliptical cross section and of specific design with an area removed 18, a slot cut through 19, and drilled through to accommodate a dished cylinder 20, itself drilled through its lateral mid point and tapped with a fine thread. Assembly of the plumb is effected by union of the threaded connector with the cylinder located within the plumb, via the slot provided.

A restraint pin 21 passing freely through the plumb completes the element.

A clear top cover 4, blind drilled as shown 22 and drilled through as required 23. The are edges bevelled at 45 24.

Assembly is effected by inserting appropriate bolts with countersunk heads through the holes in the backplate. The centre section is aligned to the backplate and pushed over the bolts. The pivot with its spacer washers is inserted intro its blind drilled hole and the length of the connector adjusted by means of its threaded section within the movement cylinder so that the cut out section of the plumb spans equally the restraint pin when placed in its seating.

The top cover is pushed over the securing bolts and the pivot and restraining pin located in their seatings. Nuts are added to the securing bolts and tightened. The device is then ready for use.

Held against a wall, the device is moved until the plumb is accurately aligned with the datum line. Free movement of the plumb about the movement cylinder and pivot ensure that the plumb assembly is perpendicular. A line drawn along either edge of the device is vertical.

If either edge of the device is placed against any other straight component and this is adjusted until the device is perpendicular, as previously described, then the component abutting the device is vertical.

The device is a measuring straight edge and has universal application.

For use in situations where hard wear is anticipated more durable materials can be used in manufacture.

The device can be produced to a high specification for all kinds of precision work or scientific application by enhancing various components.

The markings can be finer and embossed to a more stringent specification.

The pivot can be enhanced by using a bearing or a series of bearings.

The properties of the connector can be improved to enable the plumb to be aligned with greater accuracy.

The movement adjustment within the body of the plumb can be enhanced by the addition of bearings.

The accuracy of alignment of the plumb and datum can be mechanically, optically or electronically assisted.

The tolerances allowed on manufactured parts can be reduced progressively.

The quality of materials used can be improved.

Constructed from suitable materials the device may be used in total darkness or underwater. It is equally effective anywhere within the normal gravitational pull of the planet.

Claims (6)

1. A form of ruler encapsulating a plumb with an elliptical cross section, suspended from a pivot, located on a datum, within a casing, marked parallel to the edges of the ruler enabling alignment of the plumb with the datum to a true perpendicular and by the theory of parallels the edges of the ruler are also perpendicular.

2. A form of ruler as claimed in Claim 1 provided with measuring scales and angle guides.

3. A form of ruler as claimed in Claim 1 or Claim 2, including a restraint pin positioned to pass through an opening pierced in the plumb and making no contact with it when the plumb is freely suspended from its pivot, provided to prevent movement of the plumb within its casing beyond design limits.

4. A form of ruler as claimed in Claim 3 in which the plumb is of a specific elliptical section, joined to the connector by means of a dished cylinder, able to turn freely within a seating bored through the body of the plumb, drilled through its lateral mid point and tapped with a fine thread, access to its union with the threaded connector being provided by means of a slot cut in the top of the plumb.

5. A form of ruler as claimed in Claim 4 in which the specific elliptical cross section of the plumb and its assembly are designed to enable friction within the casing to be reduced a minimum, commensurate with the quality of each specific unit, by reducing the surface areas potentially in contact and the use of bearings.

6. A form of ruler as claimed in Claims 1 to 5 in which the specifications of its component parts and the quality of the materials used may be progressively enhanced to the point where the accuracy of the completed instrument may be described as absolute.