Lens arrangement and a monitoring camera comprising the lens arrangement

Abstract

A lens arrangement for a monitoring camera and a monitoring camera including a lens arrangement is provided. The lens arrangement includes a lens member having a connection portion with an outer thread, an adjustment member having a through hole for receiving the connection portion and an inner thread corresponding to the outer thread, a holder member having a receiving portion for receiving the connection portion and an inner thread corresponding to the outer thread. The lens arrangement is assembled by the connection portion being screwed into the through hole and further into the receiving portion. The receiving portion has a top engagement surface and the adjustment member has a bottom engagement surface. The adjustment member is movable relative to the holder member by screwing between non-engaging and engaging states. In the engaging state, the bottom engagement surface wedgingly engages with the top engagement surface for locking the lens member.

What is claimed is: 
     
         1 . An elastic gasket to be positioned between a top surface and a bottom surface, the elastic gasket comprising:
 a body having a z-shaped cross section and arranged to provide a force in response to compression, wherein the force is anti-parallel to a direction of the compression.   
     
     
         2 . The elastic gasket according to  claim 1 , wherein the elastic gasket comprises a silicone rubber. 
     
     
         3 . The elastic gasket according to  claim 1 , wherein the elastic gasket has an annular shape. 
     
     
         4 . The elastic gasket according to  claim 3 , in which the elastic gasket in a loaded state thereof is arranged to be subjected to a compression, the direction of compression being parallel to a central axis of the elastic gasket. 
     
     
         5 . The elastic gasket according to  claim 1 , wherein the z-shaped cross section comprises:
 a top portion, a bottom portion, and a mid portion connecting the top portion and the bottom portion;   wherein the top portion and the bottom portion have an extension along an axis parallel to the direction of compression.   
     
     
         6 . The elastic gasket according to  claim 1 , wherein the z-shaped cross section comprises:
 a top portion, a bottom portion, and a mid portion connecting the top portion and the bottom portion; and   wherein a first angle is formed between the top portion and the mid portion, and a second angle is formed between the bottom portion and the mid portion,   wherein the respective angle in a loaded state of the gasket is a function of the magnitude of a load applied to the gasket such that the respective angle decreases in a response to a larger load.   
     
     
         7 . The elastic gasket according to  claim 1 , wherein the z-shaped cross section comprises:
 a top portion, a bottom portion, and a mid portion connecting the top portion and the bottom portion;   wherein, in an unloaded state of the elastic gasket, a first right angle is formed between the top portion and the mid portion, and a second right angle is formed between the bottom portion and the mid portion.   
     
     
         8 . A system comprising:
 a top surface, a bottom surface, and an elastic gasket;   wherein the elastic gasket is arranged between the top surface and the bottom surface and the elastic gasket comprises a body having a z-shaped cross section;   wherein the elastic gasket in a loaded state, in which a distance between the top surface and the bottom surface has been reduced by a relative movement of the top surface and bottom surface towards each other along an axis, provides a force in response to engagement of the gasket with the top and bottom surfaces; and   wherein the force is anti-parallel to the axis.   
     
     
         9 . A method for using an elastic gasket to provide a force in response to compression, the method comprising:
 arranging the elastic gasket between a top surface and a bottom surface, wherein the elastic gasket comprises a body having a z-shaped cross section;   applying a load to the elastic gasket by reducing the distance between the top surface and the bottom surface by a relative movement of the surfaces towards each other along an axis, whereby the elastic gasket provides a force being anti-parallel to the axis in the loaded state.