Cam lock with torsion spring for a drawer slide

In a drawer slide having a chassis member which includes a chassis member web portion and chassis member edge portions, an intermediate member which includes an intermediate member web portion and intermediate member edge portions, and a rack member which includes a rack member web portion and rack member edge portions, wherein said intermediate member is telescopically extensible from within said rack member and said chassis member is telescopically extensible from within said intermediate member, with chassis member web portion, said intermediate member web portion and said rack member web portion extending substantially parallel to a longitudinal axis of said drawer slide, and said chassis member edge portions, said intermediate member edge portions and said rack member edge portions disposed in parallel alignment, the improvement comprising:

• a protuberance extending from said rack member web portion toward said intermediate member;
• a lock member slidably mounted to said intermediate member, said lock member having a tab formed to extend transverse to the longitudinal axis of said drawer slide,
• a window formed into said intermediate member web portion for receiving said tab of said lock member, such that said tab protrudes through said intermediate member web portion for engaging said protuberance extending from said rack member;
• a torsion spring secured to said intermediate member and engaging said lock member to move said lock member into a first position, disposed for engaging said protuberance when said intermediate member is disposed in a forward position relative to said rack member;
• and
• wherein said chassis member has a profile, such that as the chassis member is moved rearward relative to said intermediate member, said profile engages said lock member and lineally moves said lock member to a second position, with said tab disposed aside of said protuberance extending from said rack member.

A drawer slide comprising:

• a chassis member having a chassis member web portion and chassis member edge portions;
• an intermediate member having an intermediate member web portion and intermediate member edge portions,
• a rack member having a rack member web portion and rack member edge portions;
• wherein said intermediate member is telescopically extensible from within said rack member and said chassis member is telescopically extensible from within said intermediate member, with chassis member web portion, said intermediate member web portion and said rack member web portion extending substantially parallel to a longitudinal axis of said drawer slide, and said chassis member edge portions, said intermediate member edge portions and said rack member edge portions disposed in parallel alignment;
• an emboss formed into said rack member web portion to define a protuberance which extends from said rack member web portion toward said intermediate member, said emboss defining a cam surface which extends at an angle to said longitudinal axis of said drawer slide and defining a forward facing shoulder which extends adjacent to said cam surface of said emboss at an angle to said longitudinal axis of said drawer slide;
• a lock member having a main body portion and a tab formed in a lower end thereof;
• said tab extending transverse to a plane of said main body portion of said lock member and transverse to said longitudinal axis of said drawer slide, said tab having a forward shoulder and a rearward facing shoulder, and said lock member having an edge disposed on an opposite side of said lock member from said tab to define a cam follower surface;
• said lock member further having a slot and an aperture which are spaced apart and extend through said main body portion of said lock member, said slot extending transverse to said tab for receiving a fastener which slidably secures said lock member to said intermediate member, wherein said slot has a length which is longer than a width of a shank portion of said fastener such that said lock member may move lineally relative to said intermediate member, in upwards and downwards directions;
• a window formed into said intermediate web portion for receiving said tab of said lock member, such that said tab protrudes through said intermediate member web portion for engaging said emboss of said rack member web portion, said window having edges for slidably receiving opposite edges of said tab and extending in parallel with said slot, such that said tab will lineally slide within said window and said fastener will lineally slide within said slot with said lock member moving lineally upward and downward relative to said drawer slide;
• a torsion spring secured to said intermediate member and engaging within said aperture in said lock member to push said lock member into an upward position, relative to said intermediate member, with said fastener disposed in a lower portion of said slot and said tab extending through an upper portion of said window, such that said tab is disposed for engaging said forward facing shoulder of said emboss when said intermediate member is disposed in a forward position relative to said rack member;
• and
• wherein at least one of said chassis member web portion and said chassis member edges defines a chassis member profile, such that as said chassis member is moved rearward relative to said rearward end of said intermediate member, said profile engages said cam follower surface of said lock member, pushing said lock member linearly downward with said tab sliding within said window and said slot sliding downward over said fastener, such that said lock member will linearly move in a downward direction until said tab is aside of said emboss of said rack member.