Fume hood and sash control device

A sash system, comprising:

• a sash;
• a counter-weight coupled to the sash by a coupling member;
• a locking mechanism coupled to at least one of the sash and the coupling member and transitionable between an open configuration where the locking mechanism does not inhibit movement of the at least one of the sash and the coupling member, and a locked configuration where the locking mechanism inhibits movement of the at least one of the sash and the coupling member;
• and
• a controller coupled to the locking mechanism and configured to control operation of the locking mechanism to selectively transition between the open configuration and the locked configuration based on a condition of the sash;
• wherein the sash and the counter-weight are configured such that when the locking mechanism is in the open configuration, the sash lowers due to gravity wherein the coupling member comprises an upper segment and a lower segment;
• wherein the upper segment is coupled to a top of the sash and a top of the counter-weight;
• wherein the lower segment is coupled to a bottom of the sash and a bottom of the counter-weight.

A sash system, comprising:

• a sash;
• a counter-weight coupled to the sash by a coupling member;
• a locking mechanism coupled to at least one of the sash and the coupling member and transitionable between an open configuration where the locking mechanism does not inhibit movement of the at least one of the sash and the coupling member, and a locked configuration where the locking mechanism inhibits movement of the at least one of the sash and the coupling member;
• and
• a controller coupled to the locking mechanism and configured to control operation of the locking mechanism to selectively transition between the open configuration and the locked configuration based on a condition of the sash;
• wherein the locking mechanism comprises a gripping member and an electromagnet;
• wherein the locking mechanism selectively inhibits motion of the sash by engaging the gripping member with the coupling member;
• wherein the gripping member is configured to engage the coupling member due to an electromagnetic force acting between the electromagnet and the gripping member.

A sash system, comprising:

• a sash;
• a counter-weight coupled to the sash by a coupling member;
• a locking mechanism coupled to at least one of the sash and the coupling member and transitionable between an open configuration where the locking mechanism does not inhibit movement of the at least one of the sash and the coupling member, and a locked configuration where the locking mechanism inhibits movement of the at least one of the sash and the coupling member;
• and
• a controller coupled to the locking mechanism and configured to control operation of the locking mechanism to selectively transition between the open configuration and the locked configuration based on a condition of the sash;
• wherein the sash includes a ferromagnetic portion;
• wherein the locking mechanism comprises an electromagnet;
• wherein the locking mechanism is configured to selectively inhibit motion of the sash due to an electromagnetic force between the electromagnet and the ferromagnetic portion of the sash when the electromagnet is energized.

A method of controlling movement of a sash, the method comprising:

• providing a sash coupled to a counter-weight by a coupling member;
• determining, using a controller, a condition of the sash;
• operating, by the controller, a locking mechanism based on the condition of the sash to transition the locking mechanism between an open configuration where the locking mechanism does not inhibit movement of at least one of the sash and the coupling member and a locked configuration where the locking mechanism inhibits movement of the at least one of the sash and the coupling member;
• wherein the counter-weight provides a balancing force against weight of the sash, and wherein when the locking mechanism is in the open configuration, the sash tends to move toward a closed position;
• transitioning, using the controller, the locking mechanism to the locked configuration based on the condition being a first condition;
• transitioning, using the controller, the locking mechanism to the open configuration based on the condition being a second condition different from the first condition;
• wherein the first condition comprises at least one of:
• the sash lowering solely due to an effect of gravity, and
• the locking mechanism is in the open configuration and the sash not lowering;
• wherein the second condition comprises at least one of:
• the sash being manually moved,
• a time since a last movement of the sash exceeding a first threshold value,
• no person being proximate to the sash, and
• a time elapsed since a person was proximate to the sash exceeding a second threshold value.

A hood enclosure assembly, comprising:

• a hood enclosure positioned within an environment and comprising a plurality of sidewalls forming a work chamber and a front aperture configured to permit airflow between the environment and the work chamber;
• a sash adjustably coupled to the hood enclosure, wherein the sash is adjustable to cover at least a portion of the front aperture;
• a counter-weight coupled to the sash by a coupling member;
• a locking mechanism operatively coupled to at least one of the sash and the coupling member;
• and
• a controller configured to control operation of the locking mechanism to selectively inhibit movement of the sash based on a condition of the sash;
• wherein when the locking mechanism does not inhibit movement of the sash, the sash tends to lower, wherein the coupling member comprises an upper segment and a lower segment;
• wherein the upper segment is coupled to a top of the sash and a top of the counter-weight;
• wherein the lower segment is coupled to a bottom of the sash and a bottom of the counter-weight.