In one aspect, there is provided a decoupler for an accessory drive for an engine. The decoupler includes a decoupler input member and a decoupler output member. One of the decoupler input member and the decoupler output member has a clutch engagement surface. The decoupler further includes a wrap spring clutch and an isolation spring that act in series in a torque path between the decoupler input member and the decoupler output member. The wrap spring clutch has a radially inner surface and a radially outer surface. One of the radially inner and outer surfaces engages the clutch engagement surface in an interference fit with the clutch engagement surface. The decoupler further includes a volume of lubricant. During sufficiently high acceleration of the decoupler input member, there is slippage at the wrap spring clutch for a selected period of time after which the slippage stops.

In one aspect, there is provided a decoupler for an accessory drive for an engine. The decoupler includes a decoupler input member and a decoupler output member. One of the decoupler input member and the decoupler output member has a clutch engagement surface. The decoupler further includes a wrap spring clutch and an isolation spring that act in series in a torque path between the decoupler input member and the decoupler output member. The wrap spring clutch has a radially inner surface and a radially outer surface. One of the radially inner and outer surfaces engages the clutch engagement surface in an interference fit with the clutch engagement surface. The decoupler further includes a volume of lubricant. During sufficiently high acceleration of the decoupler input member, there is slippage at the wrap spring clutch for a selected period of time after which the slippage stops.

An automotive air conditioning assembly including a scroll compressor and a wrap spring clutch. The wrap spring clutch enables the use of a comparatively smaller pulley (a diameter of at most 85 mm) which comparatively increases the compressor speed and hence cooling capacity at a given engine speed. The clutch requires low power (e.g. less than 5 Watts) for continuous operation.

A method for installing a wrap spring includes providing a first sleeve with a first longitudinal axis extending in an axial direction and a lateral surface, and the wrap spring designed to frictionally abut the lateral surface. The wrap spring includes a nominal diameter and a central axis. The method includes applying the wrap spring in a relaxed state to the lateral surface at an angle α between the central axis and the first longitudinal axis, elastically twisting the wrap spring to change the nominal diameter while the wrap spring contacts the lateral surface, reducing the angle α, threading the wrap spring onto the first sleeve, and relaxing the wrap spring to establish frictional contact with the lateral surface.

A knockdown, portable lift is relatively compact and lightweight for transport and use where there is no existing means for lifting a load between a lower surface and an upper surface or where the existing means cannot be used. Components of the lift are stored in a base portion of the lift and are assembled on site for forming a lift frame extending between the upper and lower surfaces. A platform and drive assembly are supported on the lift frame and are driven together up and down tracks on each side of the lift frame using a rotary drive, such as a hand crank or electric motor, to power the drive assembly. The drive assembly is operable by a person on or off the platform from either the upper or lower surface or traversing stairs over which the platform is moving. The drive assembly incorporates a unique overspeed braking system and a unique clutch arrangement.

A knockdown, portable lift is relatively compact and lightweight for transport and use where there is no existing means for lifting a load between a lower surface and an upper surface or where the existing means cannot be used. Components of the lift are stored in a base portion of the lift and are assembled on site for forming a lift frame extending between the upper and lower surfaces. A platform and drive assembly are supported on the lift frame and are driven together up and down tracks on each side of the lift frame using a rotary drive, such as a hand crank or electric motor, to power the drive assembly. The drive assembly is operable by a person on or off the platform from either the upper or lower surface or traversing stairs over which the platform is moving. The drive assembly incorporates a unique overspeed braking system and a unique clutch arrangement.

A knockdown, portable lift is relatively compact and lightweight for transport and use where there is no existing means for lifting a load between a lower surface and an upper surface or where the existing means cannot be used. Components of the lift are stored in a base portion of the lift and are assembled on site for forming a lift frame extending between the upper and lower surfaces. A platform and drive assembly are supported on the lift frame and are driven together up and down tracks on each side of the lift frame using a rotary drive, such as a hand crank or electric motor, to power the drive assembly. The drive assembly is operable by a person on or off the platform from either the upper or lower surface or traversing stairs over which the platform is moving. The drive assembly incorporates a unique overspeed braking system and a unique clutch arrangement.

A knockdown, portable lift is relatively compact and lightweight for transport and use where there is no existing means for lifting a load between a lower surface and an upper surface or where the existing means cannot be used. Components of the lift are stored in a base portion of the lift and are assembled on site for forming a lift frame extending between the upper and lower surfaces. A platform and drive assembly are supported on the lift frame and are driven together up and down tracks on each side of the lift frame using a rotary drive, such as a hand crank or electric motor, to power the drive assembly. The drive assembly is operable by a person on or off the platform from either the upper or lower surface or traversing stairs over which the platform is moving. The drive assembly incorporates a unique overspeed braking system and a unique clutch arrangement.

A method for installing a wrap spring includes providing a first sleeve with a first longitudinal axis extending in an axial direction and a lateral surface, and the wrap spring designed to frictionally abut the lateral surface. The wrap spring includes a nominal diameter and a central axis. The method includes applying the wrap spring in a relaxed state to the lateral surface at an angle α between the central axis and the first longitudinal axis, elastically twisting the wrap spring to change the nominal diameter while the wrap spring contacts the lateral surface, reducing the angle α, threading the wrap spring onto the first sleeve, and relaxing the wrap spring to establish frictional contact with the lateral surface.

A method for installing a wrap spring includes providing a first sleeve with a first longitudinal axis extending in an axial direction and a lateral surface, and the wrap spring designed to frictionally abut the lateral surface. The wrap spring includes a nominal diameter and a central axis. The method includes applying the wrap spring in a relaxed state to the lateral surface at an angle α between the central axis and the first longitudinal axis, elastically twisting the wrap spring to change the nominal diameter while the wrap spring contacts the lateral surface, reducing the angle α, threading the wrap spring onto the first sleeve, and relaxing the wrap spring to establish frictional contact with the lateral surface.