FIELD OF THE INVENTION

The various embodiments herein relate to fans, especially fans for use in grain bins, and further to devices for locking such fans to prevent the blades from rotating as a result of wind when the fan is not in use.

BACKGROUND OF THE INVENTION

Centrifugal fans, such as the exemplary centrifugal fan2depicted inFIG. 1, are often utilized in agriculture to dry and aerate harvested crops such as corn. One disadvantage of these centrifugal fans are that they may be nearly constantly turning even while off, due to slight winds or other factors. This near constant turning can cause the fan to break or need maintenance prematurely due to overuse. The near constant turning can potentially cause worn out start switches and/or a need to replace bearings, capacitors, and motors.

Prior attempts to solve the problem of constant blade rotation include placing a block of wood in the fan to prevent the fan from turning. However, this block of wood can be forgotten and the fan turned on while the block of wood is still in place, likely destroying the fan and creating a safety hazard for anyone in the vicinity of the fan.

Another known solution to the problem of constant blade rotation is the use of a fan cover. Fan covers are placed over the opening of the fan while it is not in operation to block wind from entering the fan, thereby preventing the wind from causing the blades to turn. However, fan covers have many disadvantages, including that they can be eaten by mice and/or they may harden and crack in the sun. As a result, fan covers typically must be replaced frequently.

There is a need in the art for a device or system to safely and easily stop the blades of a centrifugal fan from rotating when the fan is not in operation.

BRIEF SUMMARY OF THE INVENTION

Discussed herein are various devices and systems for locking fan blades and disconnecting power to the fan.

In Example 1, a fan locking and disconnection device comprises a device housing coupleable to an external surface of a fan, a switch disposed within the device housing, a bolt slidably disposed within the device housing, an actuation handle operably coupled to the bolt, and an electrical cable electrically coupled at a first end to the switch, wherein the electrical cable is configured to be electrically coupleable at a second end to a fan control box. The bolt comprises a contact washer attached to the bolt, an engaged position wherein the bolt is frictionally engaged with a fan blade and the contact washer is not in contact with the switch, and a disengaged position wherein the contact washer is in contact with the switch. The actuation handle comprises a locked position wherein the bolt is in the engaged position, and an unlocked position wherein the bolt is in the disengaged position.

Example 2 relates to the device of Example 1, wherein the fan is a centrifugal fan.

Example 3 relates to the device of Example 1, wherein the device housing is coupleable to the external surface of the fan via a backing plate and mounting hardware.

Example 4 relates to the device of Example 1, wherein the electrical cable is coupled at one end to the switch and at the other end to the magnetic starter coil.

Example 5 relates to the device of Example 1, wherein, when the actuation handle is in the locked position, the power to the fan is disconnected.

Example 6 relates to the device of Example 1, wherein, when the actuation handle is in the locked position, the fan is prevented from turning.

Example 7 relates to the device of Example 1, further comprising a grain bin operably coupled with the fan.

In Example 8, a fan locking system comprises a fan, an elongate bolt, and a handle operably coupled with the bolt, wherein the handle is constructed and arranged to urge the bolt between the engaged and disengaged positions. The elongate bolt comprises an engaged position wherein the bolt is in frictional contact with the fan, and a disengaged position wherein the bolt is retracted from the fan.

Example 9 relates to the system of Example 8, further comprising a switch, an electrical cable operably coupled with the switch, wherein the electrical cable and the switch are part of an electrical start circuit for the fan, and a contact washer disposed along the bolt, wherein, when the bolt is in the disengaged position, the contact washer is in operative contact with the switch, and wherein, when the bolt is in the engaged position, the contact washer is not in contact with the switch.

Example 10 relates to the system of Example 9, wherein the electrical cable is operably coupled with a magnetic starter coil.

Example 11 relates to the system of Example 10, wherein the fan cannot be actuated when the bolt is in the engaged position.

Example 12 relates to the system of Example 11, wherein the fan is a centrifugal fan.

In Example 13, a method of controlling the blades of a fan comprises coupling a fan locking device to a side of the fan, wherein the fan locking device comprises an elongate bolt, and a handle operably coupled with the bolt. The method further comprises urging the handle into an engaged position wherein the bolt is in frictional contact with the fan, and urging the handle into a disengaged position wherein the bolt is retracted from the fan.

Example 14 relates to the method of Example 13, wherein the urging the handle into the engaged position causes power to the fan to be disconnected.

Example 15 relates to the method of Example 13, wherein the urging of the handle into the disengaged position causes power to the fan to be connected.

Example 16 relates to the method of Example 13, wherein the fan locking device further comprises a switch, an electrical cable operably coupled with the switch, wherein the electrical cable and the switch are part of an electrical start circuit for the fan, and a contact washer disposed along the bolt.

Example 17 relates to the method of Example 16, wherein the urging the handle into the engaged position causes the contact washer to not be in contact with the switch, whereby the electrical start circuit is open such that the power to the fan is disconnected.

Example 18 relates to the method of Example 16, wherein the urging the handle into the disengaged position causes the contact washer to be in contact with the switch, whereby the electrical start circuit is closed such that the power to the fan is connected.

While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. As will be realized, the invention is capable of modifications in various obvious aspects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.

