GB2159313A

GB2159313A - Number plate manufacture

Info

Publication number: GB2159313A
Application number: GB08408914A
Authority: GB
Inventors: George William Armstrong
Original assignee: ARMSTRONG ENG Ltd
Current assignee: ARMSTRONG ENG Ltd
Priority date: 1984-04-06
Filing date: 1984-04-06
Publication date: 1985-11-27
Also published as: GB8408914D0

Abstract

A layer of black material (25) is bonded to one face of a piece (13) of transparent plastics material. Then the piece of plastics material is located in a cutting die holder (1) with the layer of black material against the cutting edges (9) of letter and number cutting dies (5) accurately but simply located and held in the die holder (1). The die holder (1) and piece (13) of plastics material are subsequently passed through a press nip (3) formed by a pair of rollers (15, 17) so that the cutting edges (9) cut through said layer (25) of black material. The excess black material is then removed from the piece of plastics material (13) to leave the designs of the cutting edges (9), and a layer (27) of reflective material is then bonded onto the plastics material (13) over the remainder of the black layer (25) to form a number plate. <IMAGE>

Description

SPECIFICATION Improvements relating to number plate manufacture The present invention relates to a method of manufacturing number plates for use in vehicles.

Vehicles used on the road are individually identified and registered with a government department, by virtue of a unique set of digits i.e. numbers and letters. The set of digits is located visually on the front and rear of the relevant vehicle, on what is commonly called a number plate.

Number plates for commercial vehicles are commonly manufactured from a rectangular alloy plate on whch individual plastic moulded letters and numbers are mounted. The individual digits have rearwardly extending projections which pass through suitably located holes in the alloy plate then star washers are fitted to secure the digits in position. Whilst this method of construction is relatively cheap, it does not provide an acceptable aesthetic quality for the private motorist.

To provide the required aesthetic quality, number plates are also made by sticking letters and numbers on the rear face of a rectangular, transparent plastic plate. and then covering the letters and numbers by a sticky sheet of a suitable reflective material i.e. white or yellow.

If these latter number plates are made on site e.g. at a garage, then the garage will usually have a supply of letters and numbers made of a flexible, plastic sheet material. On any one occasion the appropriate letters and numbers are selected and positioned on the back of a transparent plastic plate using solely the eye and possibly a set of guidelines to regularize the location of the letters and numbers. The letters and numbers are sticky and by applying finger pressure, the digits can be smoothed out and secured to the transparent plate. A strip of sticky reflective sheet material is then located over the digits and smoothed down manually. This operation can provide a satisfactory end product if time and care are taken to accurately locate and evenly smooth the letters in the required pattern.

These latter number plates are alternatively manufactured in the factory by a method wherein a basic, rectangular, transparent plastic plate is passed through a roller press nip, a stripe black, flexible, plastic sheet material being smoothly rolled onto and stuck to the rear face of the plate as it passes through the press nip. The plate with bonded black strip is then located in a die holder which carries cutting blocks, the black strip facing downwards and engaging the cutting blocks. Each cutting block comprises a base on which a cutting blade in the shape of a particular letter or number, is mounted. The bases of the cutting blocks fit in the die holder with any appropriate spaces. to provide the required accurate regular pattern of numbers and letters; the die holder preventing the blocks from moving.The die holder also has a peripheral lip within which the plastic plate accurately fits with respect to the chosen cutting blocks.

With the plate and black strip located within the peripheral lip of the die holder, the die holder is then passed into a vertical press, usually of the hydraulic type. Activation of the vertical press presses the plate down onto the cutting blades of the cutting blocks, the peripheral edge of the die holder holding the plate in the required position. and the outline of the selected sequence of numbers and letters is quickly and accurately cut into the black strip of sheet material on the then underface of the plate. After removing the plate from the vertical press, the black strip is merely pulled off the plate leaving the parts of the black strip forming the cut out letters and numbers.The plate is then passed through a further roller press nip wherein a strip of reflective plastic material (white or yellow) is smoothed onto and bonded over the letters and numbers, to form the finished number plate.

Whilst this latter method is perfectly satisfactory in a factory situation, where number plates are made continuously each day, the cost of a vertical press which can provide the required pressure. is usually prophibitive for an on-site location e.g. a garage, where number plates are made only on the odd occasion.

The aim of the present invention is to provide a simple method of manufacturing a number plate, whereby it is easy to provide an accurate regular pattern of numbers and letters, without the required apparatus being capital intensive.

According to the present invention there is provided a method of manufacturing a number plate, comprising the steps of bonding a layer of material to one face of a piece of transparent plastics material, locating said plastics material in a cutting die holder with said layer of material against the cutting edges of dies mounted in said holder, passing said die holder and said piece of plastics material through a press nip formed by a pair of rollers. so that the said cutting edges cut through said layer of material, removing the excess material from said piece of plastics material to leave the design of the cutting edges, and bonding a further layer of material on said piece of plastics material over the remainder of the first material layer of material.

Thus, by virtue of the present invention, a number plate with accurately positioned numbers and letters can be produced on site e.g.

in a garage, without the need for capital intensive equipment. All that is required on site besides the raw materials for the numer plate, are a die holder and a suitable number of letter and number cutting blocks and spacers, for snug location on the holder, and a press nip formed by two parallel rollers located in a framework, the positions of the rollers with respect to each other being adjustable to vary the desired pressure which can be applied by the press nip. Preferably one roller is freely rotatable and the other roller is manually rotatable.

Additionally, two further press nips may be provided for use in the application of said layers of material, these layers preferably being in the form of sticky tape. Said first material layer is preferably black tape and the further layer is a reflective tape i.e. white or yellow.

In a preferred embodiment of the present invention the die holder is rectangular and has a rectangular recess for snugly receiving the letter and number cutting blocks for a selected number and letter sequence. Further the die holder has a peripheral lip within which said piece of plastics material can accurately fit.

Thus the relative positions of the letter and number cutting blocks and the said piece of plastic material, is fixed. This relative accurate positioning results in the desired accurate location of the letters and numbers in the finished number plate.

The present invention will now be further described, by way of example, with reference to the accompanyig drawings, in which: Figure 1 is a perspective view of one embodiment of apparatus for use in the present invention; Figure 2 illustrates a middle step in the method of the present invention; and Figure 3 illustrates the final step in the method of the present invention.

In Fig. 1, there is illustrated a die holder 1 and a press nip 3. The die holder 1 is rectangular and has a rectangular recess within which selected letter and number cutting blocks 5, together with a spacer or spacers 7, are snugly fitted. Each letter or number cutting block 5 has an upstanding cutting edge 9 defining the outline of a particular letter or number. In respect of the present invention, -the cutting edge 9 should project above the surface of the block 5, only sufficiently to cut through a thin layer of plastics tape. Thus the cutting edges 9 will not be damaged by shear force produced during passage through the press nip. The die holder 1 also has an upstanding peripheral lip 11 which mates exactly with the edge of a rectangular piece 1 3 of transparent plastics material, which is the base for the required number plate.

The press nip 3 comprises two rollers 15, 17 mounted on a framework 19. The rollers 15, 1 7 are mounted parallel to each other and are covered with a resiliently deformable material. Roller 1 5 is freely rotatable and it can be moved towards or away from roller 1 7 by adjustment of screws 21. Roller 1 7 can be rotated manually using handle 23.

Having selected the required letter and number cutting blocks 5, and spacer 7, and having located these blocks in the required sequence in the recess in the die holder 1, a strip 25 of black sticky tape is smoothed onto the undersurface of the rectangular piece 1 3 of transparent plastics material, and the piece 1 3 is mated within the upstanding lip 11 of the die holder with the strip 25 resting on top of the cutting edges 9. The cutting edges 9 are thus accurately positioned with respect to the periphery of the transparent plastic piece 13 i.e. the number plate.

With the plastic piece 1 3 located within the upstanding lip 11, the plastic piece is of sufficient thickness to still project above lip 11. Thus when the die holder 1 and plastic piece 1 3 are fed together into the press nip 3, rotation of handle 23 will draw the die holder and plastic piece through the press nip, and the plastic piece 1 3 will be pressed down into the die holder causing the cutting edges 9 to cut through the black tape 25.

When the die holder 1 and plastic piece 1 3 have passed completely through the press nip, the plastic piece 1 3 is lifted out of the die holder 1 and the black tape 25 is stripped off leaving the numbers and letters see Fig. 2.

Then a layer of reflective tape 27 (Fig. 3) is bonded onto the plastic piece 1 3 over the numbers and letters to form the finished number plate.

The present invention thus provides a simple method of producing an aesthetic number plate with accurately positioned letters and numbers, without the requirement for capital intensive equipment. The present invention is therefore particularly applicable to garage locations where use is infrequent.

Claims

1. A method of manufacturing a number plate, comprising the steps of bonding a layer of material to one face of a piece of transparent plastics material, locating said plastics material in a cutting die holder with said layer of material against the cutting edges of dies mounted in said holder, passing said die holder and said piece of plastics material through a press nip formed by a pair of rollers, so that the said cutting edges cut through said layer of material, removing the excess material from said piece of plastics material to leave the design of the cutting edges, and bonding a further layer of material on said piece of plastics material over the remainder of first layer of material.

2. A method as claimed in claim 1, in which the first layer of material is black and the further layer of material is a different colour to said first layer.

3. A method as claimed in claim 1 or claim 2, in which said first layer of material is applied to the plastics material by one press nip, before being passed with the die holder through the press nip formed by the rollers.

4. A method as claimed in any one of the preceding claims in which the plastics material and first layer of material are passed through a further press nip after the excess material has been removed from the first layer, the further layer of material being applied over the remainder of said first layer, by said further press nip.

5. A method of manufacturing a number plate, substantially as hereinbefore described with reference to the accompanying drawings.