An inverted constant force window balance system has a carrier assembly including a housing with a first and a second housing wall, a coil spring with a free end, and a shoe assembly slidably coupled to the housing. The shoe assembly includes a first and a second shoe face. The housing slides between a first and a second position relative to the shoe assembly. When in the first position, the first and second housing walls are substantially non-coplanar with the first shoe face, and when in the second position, the first housing wall is substantially coplanar with the first shoe face and substantially non-coplanar with the second shoe face. The shoe assembly receives a pivot bar from a window sash and extends a brake upon rotation thereof. The balance system also includes a mounting bracket releasably coupled to the housing and coupled to the free end of the coil spring.

An improvement in a portable building (B) comprises a ramp door (100) installed in an opening (O) formed in a sidewall (S) of the building. An upper door frame member (106) is hingedly installed to the side of building so to cover the upper end of the ramp door. When the member is in a vertical position, it prevents the ramp door from being lowered; but when the member is rotated to a horizontal position, it unblocks the upper end of the door so the door can be lowered and raised.

A counter balance device for a sash window includes a spiral balance having a hand-wound spiral rod connected to wind a torsion spring to generate an initial spring force that counter balances the window's weight for keeping the sash up when raised. The lower end of the spiral rod is connected to a rotation shaft rotatably disposed on a slide block. When a large repulsion force produced by the torsion spring is applied to the spiral rod, the rotation shaft is urged in a direction reverse to the rotation direction of the spiral rod by a buffer spring having a spring force which is larger than the initial spring force so that the rotation of the rotation shaft is tolerated.

The invention relates to a tensioning device (01) for tensioning a coil spring (02) that is supported on a main shaft (03) and at a fixed end is rotatably fixedly connected to a frame. The tensioning device (01) includes a gear drive (05), having a first gear element (06) that is axially displaceably guided on the main shaft (03) and rotatably fixedly connected to a free end of the coil spring (02), and having a second gear element (07) that is in drive engagement with the first gear element (06) in order to set the first gear element (06) in rotation about the main shaft (03). The tensioning device (01) also includes a retaining element (19) that holds the second gear element (11) in the position of drive engagement with the first gear element (06). Furthermore, the tensioning device (01) includes a drive element that is coupled to the second gear element (12) in order to set it in rotation. The gear drive is formed as a bevel gear transmission, wherein the first gear element (06) is formed as a bevel gear (06) and the second gear element (07) is formed as a bevel gear pinion (07), and wherein the rotational axes of the two gear elements (06, 07) extend perpendicularly to one another. The bevel gear (06) is integrally connected to a guide bushing (10), and has a central opening (09) through which the main shaft (03) extends, and has a cylindrical receiving section (12) in which the free end of the coil spring (02) is fastened.

A window includes a sash which is pivotally connected at a top end by a top pivot to a perimeter frame so that a bottom end of the sash is pivotal upwardly through an arc of approximately 90 degrees from a closed position to an open position of the window. A linkage arm is pivotally coupled at a first end of the arm by a first pivot at an intermediate location along a side member of the sash and at a second end of the arm by a second pivot at an intermediate location along a side member of the perimeter frame. One of the top pivot of the sash or the second pivot of the linkage arm is a sliding pivot that is longitudinally slidable along the side member of the frame. A biasing member exert a biasing force on the sliding pivot which retains the sash open.

An improvement in a portable building (B) comprising a door ramp (10) installed in an opening (O) formed in a sidewall (S) of the building. A ramp door (12) fits in the opening and is hingedly attached to the building. A handle (16) is attached to an exterior surface (12o) of the door allows a user to lower and raise the door with a mechanism (18) facilitating lowering and raising the door in a controlled manner. A panel (32) mounted to the interior top portion of the door extends outwardly as the door is fully lowered to rest on the ground and complete formation of a ramp by items can be brought into or removed from the building.

A spiral balance device for sash windows has a pipe inside of which extends a spiral rod having a screw section. A lower end of the spiral rod extends through a slot in a coupling rotatably disposed inside the lower end of the pipe and projects from the lower end of the pipe. A torsion spring has an upper end fixed near the upper end of the pipe and a lower end fixed to the coupling. A fixing member is fixed within the upper end of the pipe, and an adjustment member rotatably disposed below the fixing member engages with the upper end of the spiral rod. A ratchet mechanism disposed between the fixing member and adjustment member allows rotation of the adjustment member in a direction of winding the torsion spring and prevents rotation of the adjustment member in a direction of unwinding the torsion spring.

An adjustable length counterbalance mechanism for lift doors, frequently used for cargo trailers and garages. The adjustable length torque shaft of the counterbalance mechanism is able to accommodate many different lift door widths and is simpler to install than a fixed length torque shaft. In embodiments, the adjustable torque shaft is comprised of two outer torque shafts, each with a torsion spring and cable drum and a middle torque shaft that can be assembled together. The middle torque shaft can be inserted into each of the outer torque shafts to a selected depth to determine the length of the adjustable torque shaft.

A spiral balance device for sash windows has a pipe inside of which extends a spiral rod having a screw section. A lower end of the spiral rod extends through a slot in a coupling rotatably disposed inside the lower end of the pipe and projects from the lower end of the pipe. A torsion spring has an upper end fixed near the upper end of the pipe and a lower end fixed to the coupling. A fixing member is fixed within the upper end of the pipe, and an adjustment member rotatably disposed below the fixing member engages with the upper end of the spiral rod. A ratchet mechanism disposed between the fixing member and adjustment member allows rotation of the adjustment member in a direction of winding the torsion spring and prevents rotation of the adjustment member in a direction of unwinding the torsion spring.

A counterbalance system for a window sash in a window frame. The window frame has guide tracks. The guide tracks have wall surfaces. The wall surfaces are supported by reinforcement ribs. A mounting slot is formed in the guide track. The mounting slot is formed in a limited area of a wall that is not supported by a reinforcement rib. A coil spring is provided. The coil spring is made of a steel ribbon having a first end, an opposite second end, and a slot engagement configuration proximate said second end. The coil spring has a wide first width from its first end to the slot engagement configuration. This first width is too large to directly engage the mounting slot. The steel ribbon is reduced to a second width through the slot engagement configuration and continuing to the second end to pass into the mounting slot.