Knob with lock mechanism

Abstract

A control knob has a body and a lock mechanism. The lock mechanism acts as a safety mechanism or safeguard by biasing the knob in a locked position, thereby preventing the knob from engaging a control stem or other structure on, for example, an appliance. This prevents the knob from inadvertent rotation which may power-on an appliance, or cause a change in a current setting of an appliance which, in certain instances, may have dangerous repercussions.

What is claimed is: 
     
         1 . A knob for controlling an appliance having a control stem, the knob comprising:
 a knob body; and   a lock mechanism, the lock mechanism comprising:
 first and second stop members, each having a pad configured to frictionally engage a surface so as to prevent rotation of the knob body relative to the surface and/or movement of the knob body in a longitudinal direction relative to the surface; 
 first and second biasing members configured to force the pads of the first and second stop members, respectively, into engagement with the surface in a first, default locked state; 
 first and second grasp segments, each being moveable when a force is exerted thereon; and 
 first and second cables connecting the first and second grasp segments to the first and second stop members, respectively; 
   wherein displacement of the first and second grasp segments causes the first and second cables to move the first and second stop members against the first and second biasing members, respectively, such that the pads of the first and second stop members are disengaged from the surface resulting in a second, unlocked state, enabling the knob body to rotate and/or move in a longitudinal direction relative to the surface.   
     
     
         2 . The knob of  claim 1 , wherein the surface is a surface of the appliance, or a surface of an escutcheon plate mounted to a surface of the appliance. 
     
     
         3 . The knob of  claim 1 , wherein the lock mechanism further comprises:
 first and second stem elements disposed between the first and second cables and first and second stop members, respectively; and   first and second stem enclosures encasing the first and second stem elements, respectively;   wherein the first and second biasing members are positioned between the first and second stop members and the first and second stem enclosures, respectively, so as to force the pads of the first and second stop members, respectively, into engagement with the surface in the first, default locked state.   
     
     
         4 . The knob of  claim 3 , further comprising:
 first and second adjustable extension elements connected to the first and second stem elements, respectively, and which are configured to adjust one or more of the free length of the first and second cables, respectively or the tension of the first and second cables, respectively.   
     
     
         5 . The knob of  claim 4 , wherein ends of the first and second stem elements are connected via threaded connections to ends of the first and second adjustable extension elements, respectively, such that adjusting the threaded connections adjusts one or more of the free length of the first and second cables, respectively or the tension of the first and second cables, respectively. 
     
     
         6 . The knob of  claim 1 , wherein the lock mechanism further comprises:
 first and second angle structures for changing the direction of the first and second cables, respectively, wherein each angle structure includes:
 a pair of wall segments spaced at an angle with respect to one another, each wall segment having a hole that is sized for the respective one of the first and second cables to move therethrough; and 
 a guide pin configured for guiding the respective one of the first and second cables between the holes of the angled wall segment. 
   
     
     
         7 . The knob of  claim 1 , wherein the first and second biasing members are compression springs. 
     
     
         8 . The knob of  claim 1 , wherein the pad of the first stop member and the pad of the second stop member each have a ribbed surface. 
     
     
         9 . The knob of  claim 1 , further comprising:
 an adjustable clamp mechanism comprising a plurality of clamps, wherein each clamp is disposed in a corresponding recess of the knob body; and   wherein the plurality of clamps are configured to be disposed about the control stem.   
     
     
         10 . The knob of  claim 9 , further comprising:
 a plurality of clamp biasing members that correspond respectively to the plurality of clamps, and that are configured to force the plurality of clamps into engagement with the control stem; and   wherein each clamp biasing member is positioned in the recess corresponding to its clamp.   
     
     
         11 . The knob of  claim 9 , wherein the plurality of clamps are sized to engage the control stem when positioned in the corresponding recesses. 
     
     
         12 . The knob of  claim 1 , wherein the knob body includes a slot sized to engage the control stem. 
     
     
         13 . A knob for controlling an appliance having a control stem, the knob comprising:
 a knob body; and   a lock mechanism, the lock mechanism comprising:
 an escutcheon plate, configured to be mounted to a surface of an appliance, the escutcheon plate having a plurality of locking teeth, and further being coupled to the knob body such that the knob body rotates relative to the escutcheon plate and/or moves in a longitudinal direction relative to the escutcheon plate; 
 first and second gear elements, each having a plurality of gear teeth and a locking tooth that engages with the plurality of locking teeth of the escutcheon plate so as to prevent rotation of the knob body relative to the escutcheon plate and/or movement of the knob body in a longitudinal direction relative to the escutcheon plate; 
 first and second grasp segments, each being moveable when a force is exerted thereon, wherein the first and second grasp segments include a plurality of gear teeth in driving engagement with the gear teeth of the first and second gear elements, respectively; and 
 at least one biasing member configured to provide a force to the first and second grasp segments that is transferred to the first and second gear elements, via driving engagement of the gear teeth of the first and second grasp segments and the gear teeth of the first and second gear elements, respectively, to force the locking teeth of the first and second gear elements into engagement with the plurality of locking teeth of the escutcheon plate, in a first, default locked state; 
   wherein displacement of the first and second grasp segments causes the first and second gear elements to move, respectively, such that the locking teeth of the first and second respective gear elements are disengaged from the plurality of the locking teeth of the escutcheon plate resulting in a second, unlocked state, enabling the knob body to rotate and/or move in a longitudinal direction relative to the escutcheon plate.   
     
     
         14 . The knob of  claim 13 , wherein a biasing member is positioned between the escutcheon plate and the knob body and is configured to force the escutcheon plate and the knob body apart. 
     
     
         15 . The knob of  claim 13 , wherein the escutcheon plate comprises a plurality of tabs which engage the knob body. 
     
     
         16 . The knob of  claim 15 , wherein:
 the knob body includes a ring element;   the plurality of the tabs of the escutcheon plate are coupled to a portion of the ring element; and   wherein the plurality of the tabs of the escutcheon plate are removed from frictional contact with the ring element of the knob body when the knob body is displaced toward the escutcheon plate, thereby enabling the knob body to rotate relative to the escutcheon plate.   
     
     
         17 . The knob of  claim 13 , wherein the at least one biasing member is a spring configured to force the first and second grasp segments in a direction opposite to the force exerted thereon. 
     
     
         18 . The knob of  claim 13 , further comprising:
 a control stem coupling spacer sized to correspond to the control stem, the spacer including an inwardly tapered ramp portion.   
     
     
         19 . The knob of  claim 18 , wherein:
 the first and second grasp segments each include a clamping element; and   wherein the clamping elements of the first and second grasp segments slide into the inwardly tapered ramp portion of the control stem coupling spacer so as to engage the control stem when the knob body is displaced in the longitudinal direction toward the escutcheon plate,   20 . The knob of  claim 19 , wherein each of the clamping elements has a curved outer surface, and wherein one of the clamping elements has a flat inner surface and the other of the clamping elements has a curved inner surface.