The contributor feels that, to fully appreciate the ingenuity of Mr Carter's invention, some generalities on change ringing are neccesary, and, therefore, prefaces the description with the following details. Change ringing, in brief, is the art of ringing changes by commencing from "rounds" (1, 2, 3, 4, 5, 6), and re-arranging each successive row by a pre-determined method, until the bells ultimately assume their first position, i.e., "rounds." There are numerous "methods," each governed by definite rules and known by a certain name, such as "Plain Bob," "Grandsire," etc. The total number of changes on a given number of bells is termed the "extent," and is obtained by multiplying the numbers together; thus the extent on 3 bells = 1 x 2 x 3 = 6, and so on. A "Peal" consists of not less than 5,040 changes on any number of bells. The peals rung on given numbers of bells are named as in the Table on page 264,[see below] the "extent" being given also. Thus one would speak of "Grandsire Triples" or "Bob Royal." By rearranging each row in the simplest order, the bells "come into rounds" in a number of changes equal to twice the number of bells being rung; therefore other steps have to be talken to prevent this if it is desired to ring a peal. These steps are termed "place making" and "dodging"; bells not doing this are referred to as "hunting." "Place making" is striking two blows in one position (other than "leading" or being "behind"). "Dodging," i.e., successive alternate blows, rather more difficult to explain. Even this form of dodging and place making does not suffice on larger numbers of bells, and the aid of "bobs" and "singles" have to be invoked. It is not neccesary, however, to go further into the intricacies of change ringing, as it should be obvious to all that Mr Carter set himself no mean task when he conceived the notion of making a mechanical apparatus to do what hitherto had required one alert mind for each bell in the peal.
A course of Stedman Caters
(9 bells and Tenor Governing)
A course of Kidderminster Royal
Stedman Slow Course
We may now proceed with the description of Mr Carter's invention.
This machine actuates a battery of gongs, causing them to ring or strike in any desired order, either in plain sequence or in the manner know as "change ringing." In this latter, as practised on church bells, the changes continually vary with each "round" or sequence, the paths of the bells being interlaced in a varying and often very intricate way.
The gongs, once placed on top of the machine and struck mechanically, are now controlled by electrical contact, each of the 12 being connected with a wire to its companion plate upon the machine. They may at times be rung at the side of the machine or at any distance from it.
The machine itself is designed with the utmost compactness and efficiency. It is about 24 ins. in length, 10 ins. in width and 7 ins. in height. It is made in two tiers and seated upon a box, within which is a small motor. From the latter, by the neccesary gearing, the machine is made to ring about 28 "changes" per minute. The lower tier contains, as it were, the "brains" of the directing mechanism, and the upper tier contains the twelve plates which move transversely or across the machine, and which lie in the order or sequence to which the machine has been set to work. Each plate moves notch by notch into twelve "places" according to the term as used in "ringing". In each of these it will cause its own gong to strike once, and on being set, the plates will strike twelve different places or one "change". The next movement of the controls will cause the plates to either move on or back one notch or to lie still. In This way successive "changes" will be produced according to the setting of the machine.
The principle of the lower part of the machine is as follows, viz.: The main shaft is driven from below, and consists of a sort of skeleton cylinder of 12 rods, these will be referred to later; it has also geared wheels at each end, one of which receives the drive from below, and is fitted with a friction safety device, and the other wheel drives the second shaft, and through it the third. It is fitted at the end with a revolving "snail" or cam, the purpose of which is to oscillate a pair of control-boxes at the fron end of the machine. There is another somewhat similar on each side just within the others, the purpose of which is to oscillate two long connecting levers which join up and co-ordinate the front control boxes with the control cylinders at the back. Thus it will be observed that when the main shaft or cylinder revolves, it carries with it twelve concentric rods, oscillates the front control boxes and also causes them to have a to and fro motion governed by the control cylinders.
The second shaft referred to above has for its purpose the driving of six rods attached to it by eccentrics, these by cranks cause eleven long rods to work to and fro engaging over the top of the cylinder and reaching along to the front of the machine. The third shaft is principally for causing a contact crank to revolve round a square dial, set with pins in concentric rows according to the number of gongs or bells desired to be rung, the crank being fitted with an adjustable contact piece. Thus as it travels round it makes electric contact for two "changes."
The more intricate part of the lower tier, however, now calls for description, viz., the controls. Taking these separately:-
The control boxes: These are square shallow boxes fitted with movable pins, of these there are 15 rows and there are 6 pins in each row. Thus a box contains 90 pins and each pin is capable of being put into three positions of control in respect to further pins or levers below. Consequently, as these boxes rise or fall, or travel to and fro, as previously described, they either avoid or they press down the ends of the levers below. The pins are set according to the number of bells and according to the particular "method" desired to be rung.
The control-cylinders: These are at the back of the machine, and work with the boxes. They are fitted with 48 adjustable slides, and according to the length to which they are set so does the "throw" of the two long connecting levers vary. These rods, like the pins, are set for the number of bells and for the "method." The skeleton cylinder is the means whereby the above control action is passed on to the upper tier of the machine. Its machanism is very elaborate. It consists of 12 rods each fitted with a controlpin and with a lifting cam with which it does the work it may be called upon to do. Each rod has also a lateral action, and according, as the pins are deflected either to the left or right, so the rod is moved laterally and the cam brought into play or not as is required by the particular case of setting.
The linking up of the controls above outlined is as follows: There are 12 cranked levers below the boxes, and with ends turned up to engage with the control pins. As these are depressed they elevate corresponding arms at the back, at the top of which arms are the rocking heads and short horizontal rods into which they engage with small pins. Thus as an arm comes up its pin imparts a small rotation to the horizontal rod, there being a small scoop-shaped funnel at the other end of this rod, it follows that it can control and impart lateral movement to any pin passing through it. The pins passing through are those described as being on the cylinder rods, and as these funnels are capable of being either right, middle or left, so is the cylinder controlled in its work.
The principle of the upper part of the machine is as follows, viz.: Below are 11 long rods or levers capable of moving to and from. They engage by double "clicks" with 12 plates, to which they impart movement, but at right angles to themselves. The rods or levers are immediately above the companion ones previously referred to, and it is from these that they get their impulse. As the latter move to and from they, in a normal position, clear the upper rods, but as soon as the cylinder cam lifts a rod, then it engages with the one above by means of a lug which rises into a slot on the underside of the top rod, which has then to conform to its motion and regains its position by means of a spiral spring.
Insulated from the rest of the machine and on top is a long board carrying 12 metal strips each insulated form the other. The plates make contact with these by means of a small pillar which rises from the bed of each. Thus as the plates traverse notch by notch the various places it has to make, it carries its pillar and passes it successively over the different strips, and with each contact the gong working with that particular plate strikes once.
The images of peals are produced by the machine which has a device for drawing a chart showing the course of one bell in a peal.
If you have not seen my other material on the machine, start here.
Page created by Bill Purvis. Last update: 13th October, 2010
Contact me at: bill 'at' billp.org
|You are visitor number 1897|