A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Self Securing Ladder Locking Attachment
The disclosed Self Securing Ladder Locking Attachment is a rectangular prism shape when in it's open position (Fig 1). The attachment automatically collapses and holds and locks in closed position (Fig 3) when a ladder is loaded into the attachment, and pushed forward onto the front end striker (Fig 7). To unlock and release the ladder, press on the spring loaded catch (shown in Fig 6 c) while also pulling downwards on the lever handle (shown in Fig 6 a) until the attachment is back in the open position (Fig 1). The attachment is held in it's open position (Fig 1) by using over-centre travel in two places. The first is the line of force of gravity on the top section whereby once the pivoting flat bars move over centre and against solid stops, gravity will continue to pull the frame towards the rear, holding it in open position, against the stops. The second is the line of force on the spring, between the anchor point on the lever and the anchor point on the bottom frame. The lever when opened travels over-centre with respect to this line of force, allowing the force to continue to pull the lever and the top frame into it's open position and holding it in place. Loading the ladder and striking the front striker bar at the front end forces these two (2) over-centre actions to revert back to their original states, thus pulling the top frame into the closed and locked position. Figure1 (attachment shown in OPEN position) d d b b b d d b a a. existing roof mounted ladder rails b. flat bars or straps c. compression struts d. Shaped brackets Figure 2 (attachment shown in OPEN position) e. support bracket f. spring loaded safety catch Figure 3 (attachment shown in CLOSED position)
Self Securing Ladder Locking Attachment
The disclosed Self Securing Ladder Locking Attachment is a rectangular prism shape when in it's open position (Fig 1). The attachment automatically collapses and holds and locks in closed position (Fig 3) when a ladder is loaded into the attachment, and pushed forward onto the front end striker (Fig 7). To unlock and release the ladder, press on the spring loaded catch (shown in Fig 6 c) while also pulling downwards on the lever handle (shown in Fig 6 a) until the attachment is back in the open position (Fig 1). The attachment is held in it's open position (Fig 1) by using over-centre travel in two places. The first is the line of force of gravity on the top section whereby once the pivoting flat bars move over centre and against solid stops, gravity will continue to pull the frame towards the rear, holding it in open position, against the stops. The second is the line of force on the spring, between the anchor point on the lever and the anchor point on the bottom frame. The lever when opened travels over-centre with respect to this line of force, allowing the force to continue to pull the lever and the top frame into it's open position and holding it in place. Loading the ladder and striking the front striker bar at the front end forces these two (2) over-centre actions to revert back to their original states, thus pulling the top frame into the closed and locked position. Figure1 (attachment shown in OPEN position) d d b b b d d b a a. existing roof mounted ladder rails b. flat bars or straps c. compression struts d. Shaped brackets Figure 2 (attachment shown in OPEN position) e. support bracket f. spring loaded safety catch Figure 3 (attachment shown in CLOSED position)
Self Securing Ladder Locking Attachment
DENNIS STEVEN (author) / DENNIS SHEREE (author)
2021-11-04
Patent
Electronic Resource
English