LOCKS AND LATCHES

Wanganui Chronicle, Volume LXXXI, Issue 18785, 19 May 1923, Page 14

LOCKS AND LATCHES

A GLANCE AT THE HISTORY OE THE SUBJECT. If v<’ refer to a di<tioi>arv, we will ■ find Hint the definition of lock there. ■ given is “An instrument or appliance j i.-cd to fasten doors, chests. and 'ho : like.” It will he .seen, tlieiefore. that tho subject i- large .;i,d that it woi.’M ! take many pages to dost ribo even a .-mall percentage ol the c.ilferent kinds oi locks now *n use It has not been fixed with any degree ol aeeiira when locks were :i«>t brought into use, Imt it is known th- i the ancients c.f Pompeii and other ruined <itbs had locks which were opened by keys very similar to those <d : the present day. and probably working on the same principle Should anvoim visit the mediaeval museum.-; ol Europe ami chance to sec among the curiosities of iionwork some of the elaborately wrought locks of ' be I Ith. loth, and 16th centuries. he would hardly think of comparing tbc-e unwieldlv and < umhc“soine devices with the locks of die present day. And \<t. if wo examine them clofcclv. it will he at once seen di.it the differnee between the old and the new is one ofi finish and delicacy rather than of idea or mechanism, and that widi the ox- < ention of a !<w minoi inventions for obtaining grvilcr security against buiglars, the locks that we see displayed in our ironimmgmy establishments and in common use at th-*' present time aiv similar as regards Hie mam principles. to those of our forefathers. ‘The locks used i) the .Middle A-'s wore hand forged, and were often cased in oak. consequently they were able to tand for many years, and. in fact, several specimens nay bo seen on some of the old buildings of Eurojxi in peril* ■ il\ good order and presci vation. alter; Icing in use fo»’ centuries. The.->e| locks wore made on the- ward principl *. i that is to .say, die leeks were made with ' elaborate network of wards, and T.ho, keys cut with unique patterns to hi. j dic.se wards 'The locks were often! about i2iii. in size*, or even larger. :■ nd | the keys so largo and heavy that nn person would hi ve thought of carrying diem about, much less oi putting them 1 in his vest pocket as we do to-day. It is only within the last twenty ' years that wo have improved so greatly! in locks, which improvement is mostly due to the Yale and lever systems The Bramah lock was introduced in 1788. It consisted of a revolving cylinder m which were a series of Hat sides working up and down in a fixed horizontal place. Ihe key consisted of a tube on die sides of which were straight grooves coricsponding to tlm elides. These leeks ire very seldom' seen at the present day. Lever locks introduced bv Chubbs in I ISIS and now m general use, with the! levers placed upright ami the. key designed to raise them, are made with | from one lever to six levers, ami 3 I little reflection will enable one to comprehend the number of changes thc\ I render possible. With a six-lever lock.' i ,776,00*0 changes can be obtain'd', which means that practically no iwoi of these six lever locks can be operated, with the sama key. Within recent years the United states oi America quite revolctionised the lock trade, when the Yale ami lowne 51fg. Co. placed their Yale locks on the markets of the world. 3he Yale system, invented by Linus Yale about thirty years ago, is nearly die only invention oi practical utility which is a direct departure fiom the old methods of lock making. 'Hie following are. a jew of the many advantages of the Yale lock over the old system . - 1. 'The key is smaller than any other in existence and oi a more convenient shape. 2. The possible changes are increased immensely; thousands instead of doizens. 3. Ihe safety against picking is I r.im i) greater. Undoubtedly the feature of 51 r. Yale’s invention which made the deep-1 est impression on the public was the' small flat key, only one-third in length ' and about one-tenth in weight of i he 1 keys then in general use, but tho fundamental inventions which made the small key possible- were tho detached! •‘cylinder,’’ containing the tumbler I mechanism, the “plug” to support the! flat key during its rotation, and dm “piiptumbler” mechanism.