SINGLE-THROW BAR LOCK OPERATING WITH A CONVENTIONAL CYLINDER

Abstract: A single-throw bar lock operating with a conventional cylinder, comprising two parallel toothed plates (3, 8), two bars (20) fixed to them, a main gear wheel (4) and an auxiliary gear wheel (5) which are interposed between said toothed plates and engage with them, said main gear wheel being in the form of a ring gear which is incomplete due to the presence of a slot, said auxiliary gear wheel being a complete circular gear wheel and each of said toothed plates having a discontinuity in the toothing by virtue of a recessed portion (7, 7′).

Description: This invention relates to a single-throw bar lock operating with a conventional cylinder. More particularly, the invention relates to a bar lock operating with a cylinder of Yale profile provided with a DIN cam or similar, in which the bars undergo their maximum travel by a single throw corresponding to a 360° rotation of the key. Said cylinders are normally available commercially as they are used in normal locks, and thus the bar locks according to the present invention have considerable advantages over currently known bar locks, which require a specially constructed cylinder. In this respect, bar locks are currently known consisting of two toothed plates operated by a cylinder provided with a specially constructed gear wheel. One end of said plates engages with said gear wheel while the other end is generally connected to another plate which acts as the bar. Said gear wheel, on rotation, extends or retracts the two plates along a straight line in opposite directions to each other, with the result that the system lengthens on locking the door, by which the bars engage in the appropriate seats provided in the door posts, and the system shortens on unlocking the door as the bars disengage from said seats. This type of bar lock has the serious drawback of operating only with a specially constructed type of cylinder, which is difficult to obtain and replace if faulty. In accordance with the present invention, we have now discovered a new type of bar lock operating with a conventional cylinder of Yale profile with a DIN cam or similar, which also has the advantage that maximum travel is obtained by a single throw corresponding to a 360° rotation of the key. The single-throw bar lock operating with a conventional cylinder according to the present invention is characterised by comprising two parallel toothed plates, two bars fixed to them, a main gear wheel and an auxiliary gear wheel which are interposed between said toothed plates and engage with them, said main gear wheel being in the form of a ring gear which is incomplete due to the presence of a slot, said auxiliary gear wheel being a complete circular gear wheel and each of said toothed plates having a discontinuity in the toothing by virtue of a recessed portion. These and further characteristics and advantages of the bar lock according to the present invention will be more apparent from the detailed description given hereinafter with reference to the relative figures, which show preferred embodiments of the invention by way of non-limiting example. Figures 1 to 4 show overall views and details of the bar lock, Figures 5 to 8 illustrate charactertistics of the bar lock cover, and Figures 9 to 11 show the main gear wheel. With reference to the numerals which indicate the various elements of the figures, the reference numeral 1 indicates the seat into which the cylinder of Yale type is inserted, and 2 indicates the cylinder protuberance which on turning the key causes the main gear wheel 4 to rotate. By means of the system comprising the gear wheel 4 and toothed plates 3 and 8 which engage the gear wheel 4 by means of the toothings 6 and 6′, the rotary movement transmitted to the gear wheel 4 by turning the key is transformed into a rectilinear to-­ and-fro movement of the toothed plates 3 and 8 and thus of the bars 20 fixed to them, so as to effect locking and unlocking. The reference numeral 5 indicates the auxiliary gear wheel which, on rotation, transmits movement from one toothed plate to the other and ensures that the plates move without discontinuity when the main gear wheel 4 is in such a position that the protuberance 2 lies in the untoothed recesses 7 and 7′ of the plates 3 and 8, as shown in Figure 2. Special characteristics of the bar lock according to the present invention are the shape of the main gear wheel 4 which is shown in detail in Figures 9 to 11 and the shape of the toothed plates 3 and 8. As can be clearly seen from Figures 9 to 11, the main gear wheel 4 is in the form of a ring gear which is incomplete due to the presence of the slot 9 designed to house the protuberance 2. The reference numeral 10 indicates the surface by which the gear wheel 4 rests against the toothed plate. In their toothing, the toothed plates 3 and 8 comprise discontinuity recesses 7 and 7′ which receive the protuberance 2 during its rotation, as shown in Figure 2. When the protuberance 2 is in the position shown in Figure 2, the main gear wheel operates only the plate 8, and the movement of the plate 8 is transmitted to the plate 3 by the auxiliary gear wheel 5. Two bars 20 are fixed to the outer ends of the toothed plates either directly or by intermediate plates 16, and on locking the door they engage in the appropriate seats provided in the door posts. As is apparent from the description and figures, a single throw effected by only one 360° turn of the key causes the bars 20 to extend by their maximum amount, so making the bar lock according to the present invention extremely advantageous and practical. A further characteristic of the bar lock according to the present invention shown in Figures 3 to 8 is that two mushroom-shaped elements 19 fixed to the bars 20 engage, during locking, with slots 23 in two plates 22 fitted to the inside of the cover 21, so preventing its removal when the lock is in its locked state.

Claims: 1. A single-throw bar lock operating with a conventional cylinder, characterised by comprising two parallel toothed plates, two bars fixed to them, a main gear wheel and an auxiliary gear wheel which are interposed between said toothed plates and engage with them, said main gear wheel being in the form of a ring gear which is incomplete due to the presence of a slot, said auxiliary gear wheel being a complete circular gear wheel and each of said toothed plates having a discontinuity in the toothing by virtue of a recessed portion. 2. A bar lock as claimed in claim 1, characterised in that the lock cylinder can pass through the inner circle of said ring gear. 3. A bar lock as claimed in claim 1, characterised in that said slot of said main gear wheel houses the protuberance which is operated by the key and causes said main gear wheel to rotate. 4. A bar lock as claimed in claim 1, characterised in that said main gear wheel engages said toothed plates to impress upon them, by means of its rotation, the to-and-fro movement for locking and unlocking purposes. 5. A bar lock as claimed in claim 1, characterised in that said auxiliary gear wheel engages said toothed plates to ensure regularity of movement of both of them, which would otherwise be compromised on passage of the protuberance through said recessed portions. 6. A bar lock as claimed in claim 1, characterised in that two mushroom-shaped elements fixed to said bars engage, on locking, with slots in two plates fitted to the inside of the cover to prevent its removal when the lock is in its locked state.

Inventors: MAZZOLI, RENATO
Applicants: ISEO SERRATURE SPA
Application year: 1987
Main classification: E05B17
IPC codes: E05C9