Sequential key locking and releasing arrangement

Claim 2

Sequential key locking and releasing arrangement for an apparatus having different operational conditions, comprising: a set of selector keys correlated with the different conditions of the apparatus, respectively, and being movable between normal inoperative positions, and actuated positions for placing the apparatus in said conditions, respectively; releasable locking means for locking said selector keys in said normal inoperative positions; and a starting key movable between an inoperative normal position, and an actuated position for obtaining a required starting condition of the apparatus, said starting key in said actuated position operating said locking means to release said selector keys of said set so that any condition of the apparatus can be selected by operation of the respective selector key only after the apparatus has been set to the required starting condition by said starting key.

Claim 3

Arrangement as claimed in claim 1 wherein said apparatus is a taximeter; wherein said starting key is correlated with the vacant condition of the taximeter, and is a ''''vacant'''' key.

Claim 4

Arrangement as claimed in claim 1 wherein each selector key and said starting key includes a key stem; wherein said locking means includes a locking slide extending across said key stems, and spring means urging said locking slide to a normal position locking said key stems of said selector keys, said locking slide being operable by said key stem of said starting key in said actuated position to move to said releasing position for unlocking said key stems of said selector keys.

Claim 5

Arrangement as claimed in claim 3 wherein said locking slide has a slot and an abutment for each key stem of said selector keys so that said abutments block said selector keys in said normal position of said locking slide, and said slots permit movement of said selector keys to said actuated positions in said releasing position of said locking slide, said locking slide having a slanted face cooperating with said key stem of said starting key so that movement of said starting key to said actuated position moves said locking slide to said releasing position.

Claim 6

Arrangement as claimed in claim 1 comprising arresting means for arresting said selector keys and said starting key in said actuated positions, respectively; and wherein movement of any selector key to said actuated position operates said arresting means to release said starting key arrested in said actuated position; and wherein subsequent movement of any other selector key operates said arresting means to release the preceding last arrested selector key.

Claim 7

Arrangement as claimed in claim 5 wherein each selector key and said starting key includes a key stem having a projection; wherein said arresting means includes a spring biassed arresting comb mounted for angular movement and having prongs respectively abutting said key stems so that during movement of any key to said actuated position said projection lifts said arresting comb whereupon said projection is engaged by the respective prong for arresting the respective key in said actuated position, and so that movement of any other key to said actuated position lifts said arresting comb to release said projection of the last operated key whereupon said other key is arrested.

Claim 8

Arrangement as claimed in claim 6 further comprising a special key having a special key stem with a smooth surface cooperating with a prong of said arresting comb for lifting said arresting comb to release said projection of the last operated and arrested key during movement of said special key to said actuated position, said smooth surface slidingly engaging the respective prong so that said special key is not arrested in said actuated position thereof.

Claim 9

Arrangement as claimed in claim 7 wherein said apparatus is a taximeter; wherein said starting key is correlated with the vacant condition of said taximeter; wherein said starting key is a ''''vacant'''' key; and wherein said special key is a ''''cash'''' key correlated with a condition of said taximeter in which only the distance of travel is measured.

Claim 10

Arrangement as claimed in claim 1 wherein each of said selector keys and said starting key include a key stem, and a transparent hollow push button mounted on said key stem for angular movement between a normal position for enveloping a lamp, and a servicing position in which the lamp is accessible.

Claim 11

Arrangement as claimed in claim 1 wherein said selector keys and said starting key are spring-biassed toward said normal position; wherein each selector key and said starting key includes a key stem having a projection; wherein said locking means includes a locking slide extending across said key stems and having a slot and an abutment for each projection of said selector keys, and spring means urging said locking slide to a normal position in which said abutments are located in the paths of movement of said projections of said selector keys, said locking slide having a slanted face cooperating with said projection on said key stem of said starting key so that movement of said starting key to said actuated position moves said locking slide to a releasing position in which said slots are located in the paths of movement of said projections of said selector keys; comprising a supporting plate parallel with said locking slide and forming a confined space with the same, and a row of round locking elements located in said space so that said projection of any single key stem enters between two locking elements during movement of the respective key to said actuated position whereby said locking elements block movement of said projection of any other key stem during movement of the respective other key to said actuated position.