A Dissertation on the Construction of Locks: Containing, First - Reasons and Observations, Demonstrating All Locks, which Depend on Fixed Wards, to be Erroneous in Principle, and Defective in Point of Security. Secondly - a Specification of a Lock, Constructed on a New and Infallible Principle, Which, Possessing All the Properties Essential to Security, Will Prevent the Most Ruinous Consequences of House Robberies, and be a Certain Protection Against Thieves of All Descriptions

author. Sold, 1785 - 46 pages
0 Avis
Les avis ne sont pas validés, mais Google recherche et supprime les faux contenus lorsqu'ils sont identifiés

Avis des internautes - Rédiger un commentaire

Aucun commentaire n'a été trouvé aux emplacements habituels.

Pages sélectionnées

Table des matières

Autres éditions - Tout afficher

Expressions et termes fréquents

Fréquemment cités

Page 43 - ... by thofe keys, which as is well known, may be procured at the old iron (hops to fit almoft any lock in ufe. Such robberies are generally committed where the fervants are allowed to take the key with them, when fent on errands, it being impracticable while the key is fixed in the lock. The variations...
Page 31 - The inviolable reftraint upon this lock, by which means it is fubjected only to the action of the key, is lodged in the part E, which is a thin plate, bearing at each extremity on a block, and having of courfe a vacant fpace beneath, equal in height to the thicknefs of the blocks on which it refis.
Page 14 - ... which acts upon the tumbler as the tumbler acts upon the bolt: the application therefore of any force to the tumbler, which is fuperior to the force of the fpring, will caufe it to quit its hold, and fet the bolt at liberty.
Page 32 - ... unequal pressure upon the levers, be formed into a groove in a direct line with the edge of the plate E, which the notches are exactly fitted to receive. The least motion of the machine, while the levers are in this...
Page 18 - By giving (fays he) an uniform motion to the tumblers, and prefenting them with a face which exaitly tallies with the key, they ftill partake, in a very great degree, of the nature of fixed wards; and the fecurity of his lock is thereby rendered in a proportionable degree defective. Thus, fuppofe the falfe key to have pafled the wards, and to be in contact with the moft prominent of the tumblers, the impreffion, which the flighteft touch will leave on the key, will direct the application of the nie...
Page 42 - ... fufpended till the notches on the projections of the fliders are forced, by the preflure of the key, into a line with each other : a groove being thus formed on the fpherical furface of the barrel...
Page 27 - As nothing (says he) can be more opposite in principle to fixed wards than a lock which derives its properties from the motion of all its parts, I determined that the construction of such a lock should he the 'subject of my experiment.
Page 36 - The key must therefore be made first, and the inequalities upon the surface of the bit worked as chance or fancy may direct, without any reference to the lock. The key being thus completed and applied to the surface of the levers, will, by a gentle...
Page 43 - ... of the levers ; the other from the number of points contained on the projected furface of each lever ; by which the pofition of its notch may in the fmalleft degree be varied.
Page 7 - The principle on which all locks depend, is the application of a lever to an interior bolt, by means of a communication from without ; so that, by means of the latter, the lever acts upon the bolt, and moves it in such a manner as to secure the...

Informations bibliographiques