GB2037045A - Actuation of counters - Google Patents

Abstract

A counter 7 is operated by moving a component 2 back and forth rectilinearly. The movement is converted into a rotary movement by a pin and helical groove connection 3, 15 and a shaft 13 turns by virtue of the back and forth movement to rotate the figure wheels of the counter through a ratchet mechanism. <IMAGE>

Description

SPECIFICATION Counting device This invention relates to a counting device which includes a barrel counter unit.

Barrel counter units are known and comprise at least one wheel but more usually a number of wheels each having indicia representing numerals arranged in order around its circumferential surface with one of the numerals being visable at a display location, the arrangement being that on turning the wheel through a predetermined angle in the same direction, being the indexing or counting direction, the numeral presented at the display location is replaced each time by the next in order.

Conventionally, in barrel counter units working on the decimal system, indicia representing ten numerals from zero to nine are arranged in order around the circumference of the wheel; indexing the wheel corresponds to a turning through one tenth of a revolution; and the adjacent coaxial wheel is geared there-to so that the eventual rotation of the first mentioned wheel through a complete revolution results in the turning of the adja- cent wheel by a tenth of a revolution. The wheels are held in indexed position and are prevented by indexing backwards by means of a suitable ratchet device embodied in the unit.

It is also to be mentioned that it is not necessary that the wheel be marked in a decimal system that the wheels turn one tenth of a revolution upon indexing or that adjacent wheels be indexed only when the relevant neighbouring wheel has completed one revolution.

To the best of our knowledge barrel counter units have hitherto been used only for the counting the revolutions of or distance travelled by objects which rotate such as wheels.

The present invention resides in a novel and inventive adaptation of barrel counter units.

According to the invention there is provided a counter comprising a barrel counter unit and a component mounted for linear back and forth movements, the body being so mounted that during each back and forth movement, by a camming action, the component or an auxiliary component in engagement therewith is caused to turn, and said turning effects indexing the figure wheel or one of the figure wheels of the counter unit whereby the wheel is indexed to count each back and forth movement of said component.

The said component preferably is piston mounted on a casing so as to be able to be moved back and forth linearly relative to the casing and also to turn about its axis during such movement. The casing may have projections which engage slots in the piston and which, at least over part of their lengths, follow a helical path to cause the piston to turn as aforesaid.

Preferably spring means is provided to urge the piston in one direction.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, wherein Figure 1 is an end elevation of the counter according to the embodiment; Figure 2 is a sectional elevation of the counter of Fig. 1, the portion of the Figure to the left of line Z-Z being a section along the line X-X of Fig. 1, and the portion to the right of line Z-Z being a section on the line A-A of Fig. 1; and Figure 3 is a sectional elevation of the counter shown in Fig. 1, the section being taken on line B-B of Fig. 1, the counter being shown in a different position from that shown in Fig. 2.

In the drawings, a barrel counter unit 7 has four counter wheels for units, tens, hundreds and thousands, and appropriate ratchet means to control the index movements of the wheels and to prevent back indexing thereof. The unit 7 is attached by screws 10 to a plate 9 through which a drive spindle 1 3 of the unit 7 passes. The plate 9 is securely mounted in a tube 1 of translucent material by pins 6.

The counter includes a piston 2 which is movable back and forth with respect to a plastics material casing 4. Piston 2 has a bore of which a portion is of square section and this portion is engaged drivingly by a length of spindle 1 3 which is also a square section.

A conical compression spring 5 is located between the end plate 9 and the head 1 4 of the piston 2 to urge the piston 2 into the position shown in Fig. 2.

Diametrically opposite grooves 1 5 are formed in the piston 2, and integral projections 3 of casing 4 project into the grooves 1 5. The grooves are helical for a part of their length so that as piston 2 is moved into the casing 4 against the pressure of the spring 5 such as to a position shown in Fig. 3, the projections engaged in the grooves 1 5 cause the piston 2 to turn. In so turning. the piston turns the square drive spindle 1 3 which drives the unit wheel 1 6 of the counter unit 7. The grooves 1 5 are so shaped that during the first half of the inward movements of the piston a rotation of 44 is produced whilst during the remaining half of the inward movement there is no rotation.The spindle 1 3 is caused to turn 8" more than one tenth of a revolution to allow for effective operation of the ratchet means. Fig. 2 shows at the right hand side the indicia of the figure wheels which are displayed on the circumferential surfaces of the wheels; the indexing of unit wheel 1 6 results in the figure FOUR being replaced, on one indexing from the position shown, by figure FIVE.

On th return of the piston 2 from the position shown in Fig. 3 to that shown in Fig.

2 under the influence of the spring 5, the piston 2 and the spindle 1 3 rotate in the opposite direction, but the ratchet mechanism in the counter unit 7 prevents the return of the unit wheel 1 6 to its former position. Thus, successive inward and outward movements of the piston 2 result in successive indexing movements of the unit wheel 16 and each complete resolution of a figure wheel results, in conventional manner, in the indexing by one unit of the adjacent figure wheel.

The mounting of the counter unit and other components within tube 1 is primarily for convenience and is not an essential feature of the invention. The tube 1 is moulded in piastics material and is closed at one end by an integrally moulded end cap 8 and is open at the other end 11 so that the reciprocating member, the movements of which are to be counted, can enter the tube 1 and engage the end of the piston 2.

In use, the device is mounted in relation to the reciprocating member so that as the member reciprocates it pushes the piston 2 into the cylinder 4 at least far enough to ensure that the spindle 13 is rotated by a full 44".

The further movement of the piston with no rotation allows for a certain amount of tolerance in the application of the counter to reciprocating bodies of different linear throws.

Modifications are possible without departing from the scope of the invention. Thus, for example instead of the pin 3 and grooves 1 5 being as shown grooves could be formed in the internal wall of the cylinder 4 and the corresponding pins arranged to project from the piston 2 to engage the grooves to effect a similar rotation of the piston when it is pushed into the cylinder.

Instead of the piston being movable back and forth, a component around the piston could be arranged to be displaced back and forth the piston forming an auxiliary component, connected to said other component so as to be turned by the other component as it is moved back and forth.

Moreover, the invention is applicable to counters operating on other systems than decimal, and the angular rotation of the figure wheels effected by the axial movement of the transmission means may be modified accordingly.

In the embodiment shown in the drawings the counter is particularly applicable for use with a reciprocating member which moves approximately linearly and can be arranged to move along the axis of the figure wheels. By removing part of the tube 1, however, the piston 2 could be pushed inwardly by other moving bodies, for example a rotating eccentric wheel.

Claims (6)

1. A counter comprising a barrel counter unit and a component mounted for linear back and forth movements, the body being so mounted that during each back and forth movement, by a camming action, the component or an auxiliary component in engagement therewith is caused to turn, and said turning effects indexing the figure wheel or one of the figure wheels of the counter unit whereby the wheel is indexed to count each back and forth movement of said component.

2. A counter according to Claim 1, wherein the said component is piston mounted on a casing so as to be able to be moved back and forth linearly relative to the casing and also to turn about its axis during such movement.

3. A counter according to Claim 2, wherein the casing has projections which engage slots in the piston and which, at least over part of their lengths, follow a helical path to cause the piston to turn.

4. A counter according to Claim 2 or 3, including spring means acting against which the piston moves in moving in one direction and which serves to return the piston to an initial position.

5. A counter according to any preceding Claim including a tube having a closed end and in which the counter unit and other components of the counter are contained.

6. A counter substantially as hereinbefore described with reference to the accompanying drawings.