Back rest for a chair

Claim 2

A back rest for a chair, in particular an office chair, comprising a base plate (11) having a rear side and edges (16, 19, 41); and a concealing shell (14) having rims (35, 37, 42), the concealing shell (14) being disposed at the rear side of the base plate (11), and concealing with said rims (35, 37, 42) the base plate (11) in an area of said edges (16, 19, 41), wherein the base plate (11) and the concealing shell (14) each are provided with connecting elements, which are engageable with each other and a pair of which forms a hook connection, which hook connection is lockable or releasable by displacing the base plate (11) and the concealing shell (14) in relation to each other and in a direction of displacement (38) substantially parallel to each other wherein the base plate (11) is provided with a padding (12), which embraces said edges (16, 19, 41) of the base plate (11) with padding strips (36, 39).

Claim 3

A back rest according to claim 1, wherein at least two hook connections are provided, which are disposed in relation to each other in the direction of displacement (38) and which are disposed at a distance (a, a') from each other.

Claim 4

A back rest for a chair, in particular an office chair, comprising a base plate (11) having a rear side and edges (16, 19, 41): and a concealing shell (14) having rims (35, 37, 42), the concealing shell (14) being disposed at the rear side of the base plate (11), and concealing with said rims (35, 37, 42) the base plate (11) in an area of said edges (16, 19, 41), wherein the base plate (11) and the concealing shell (14) each are provided with connecting elements, which are engageable with each other and a pair of which forms a hook connection, which hook connection is lockable or releasable by displacing the base plate (11) and the concealing shell (14) in relation to each other and in a direction of displacement (38) substantially parallel to each other, wherein each hook connection comprises a hook (17, 17', 20, 20') and an abutment (22, 22', 23, 23') as connection elements, one of said connection elements being disposed at the base plate (11) another one of said connection elements being disposed at the concealing shell (14) and wherein each hook (17, 17', 20, 20') has a stand (28, 24) with a projection (29, 25) and wherein each abutment (22, 22', 23, 23') has a receiver opening (30, 26) to receive said projection (29, 25) while displacing the base plate (11) and the concealing shell (14) in relation to each other and in the direction of displacement (38) wherein the base plate (11) is provided with a padding (12), which embraces said edges (16, 19, 41) of the base plate (11) with padding strips (36, 39).

Claim 5

A back rest for a chair, in particular an office chair, comprising a base plate (11) having a rear side and edges (16, 19, 41): and a concealing shell (14) having rims (35, 37, 42), the concealing shell (14) being disposed at the rear side of the base plate (11), and concealing with said rims (35, 37, 42) the base plate (11) in an area of said edges (16, 19, 41), wherein the base plate (11) and the concealing shell (14) each are provided with connecting elements, which are engageable with each other and a pair of which forms a hook connection, which hook connection is lockable or releasable by displacing the base plate (11) and the concealing shell (14) in relation to each other and in a direction of displacement (38) substantially parallel to each other, wherein each hook connection comprises a hook (17, 17', 20, 20') and an abutment (22, 22', 23, 23') as connection elements, one of said connection elements being disposed at the base plate (11) another one of said connection elements being disposed at the concealing shell (14) and wherein each hook (17, 17', 20, 20') has a stand (28, 24) with a projection (29, 25) and wherein each abutment (22, 22', 23, 23') has a receiver opening (30, 26) to receive said projection (29, 25) while displacing the base plate (11) and the concealing shell (14) in relation to each other and in the direction of displacement (38) wherein the base plate (11) is provided with a padding (12), which embraces said edges (16, 19, 41) of the base plate (11) with padding strips (36, 39).

Claim 6

A back rest according to claim 3, wherein at least one hook is formed as a locking hook (17, 17').

Claim 7

A back rest according to claim 3, wherein at least one hook is formed as a retaining hook (20, 20').

Claim 8

A back rest according to claim 4, wherein the locking hook (17, 17') has a stand (28) with a projection (29), wherein each abutment (22, 22') has a receiver opening (30) to receive said projection (29), and wherein the locking hook (17, 17') has an undercut (32) to receive the abutment (22, 22') at a retaining surface (31), facing the base plate (11), of the projection (29).

Claim 9

A back rest according to claim 5, wherein each retaining hook (20, 20') has a stand (24) with a projection (25), wherein each abutment (23, 23') has a receiver opening (26) to receive said projection (25) and wherein said projection (25) of said retaining hook (20, 20') has a guide surface (27) extending in an inclined manner towards the base plate (11).

Claim 10

A back rest according to claim 3, wherein an extension (b) of the projection (25) of the retaining hook (20, 20') counter to the direction of displacement (38) is slightly larger than an extension (c) of the projection (29) of the locking hook (17, 17').

Claim 11

A back rest according to claim 8, wherein the abutment (22, 22') of the locking hook (17, 17') is elastically deformable counter to the direction of displacement (38).

Claim 12

A back rest according to claim 1, wherein the rims (35, 37, 42) of the concealing shell (14) abut on the padding strips (36, 39).

Claim 13

A back rest according to claim 3, wherein at least one of said rims (37), located in the direction of displacement (38), of the concealing shell (14) is elastically deformable.

Claim 14

A back rest according to claim 3, wherein the rims (35, 37, 42) of the concealing shell (14) abut on the padding strips (36, 39).

Claim 15

A back rest for a chair, in particular an office chair, comprising a base plate (11) having a rear side and edges (16, 19, 41): and a concealing shell (14) having rims (35, 37, 42), the concealing shell (14) being disposed at the rear side of the base plate (11), and concealing with said rims (35, 37, 42) the base plate (11) in an area of said edges (16, 19, 41), wherein the base plate (11) and the concealing shell (14) each are provided with connecting elements, which are engageable with each other and a pair of which forms a hook connection, which hook connection is lockable or releasable by displacing the base plate (11) and the concealing shell (14) in relation to each other and in a direction of displacement (38) substantially parallel to each other, and wherein at least one of said rims (37), located in the direction of displacement (38), of the concealing shell (14) is elastically deformable wherein the base plate (11) is provided with a padding (12), which embraces said edges (16, 19, 41) of the base plate (11) with padding strips (36, 39).

Claim 16

A back rest for a chair, in particular an office chair, comprising a base plate (11) having a rear side and edges (16, 19, 41): and a concealing shell (14) having rims (35, 37, 42), the concealing shell (14) being disposed at the rear side of the base plate (11), and concealing with said rims (35, 37, 42) the base plate (11) in an area of said edges (16, 19, 41), wherein the base plate (11) and the concealing shell (14) each are provided with connecting elements, which are engageable with each other and a pair of which forms a hook connection, which hook connection is lockable or releasable by displacing the base plate (11) and the concealing shell (14) in relation to each other and in a direction of displacement (38) substantially parallel to each other, and wherein at least one of said rims (37), located in the direction of displacement (38), of the concealing shell (14) is elastically deformable wherein the base plate (11) is provided with a padding (12), which embraces said edges (16, 19, 41) of the base plate (11) with padding strips (36, 39).

Claim 17

A back rest according to claim 13, wherein the rims (35, 37, 42) of the concealing shell (14) abut on the padding strips (36, 39).