Keys, Joint Box are tools used for lifting street covers. Specialist
training on how to remove covers was always given due to the issues caused
by the weight of the covers.
Tools and Transport
Hand
Tools
K1005
Issue 1 - 12.12.1966
Key, Joint Box No. 2
1. General
This Instruction describes
a key for lifting footway-type covers. It can also be used on the covers of
Frames and Covers, Unit Type, Light and Frames and Covers, Carriageway, No.
4. The precautions to be observed to avoid strain injury are outlined in
GENERAL, General, Z 1020.
2. Description
The key is illustrated
below and consists of a stem similar to the normal type of lifting key
acting as a fulcrum about which a lever is pivoted. The action of lifting
the lever causes the front end pad to be pushed firmly against the cover.
This results in a firmer and more reliable grip of the tongue in the keyhole
and also strongly restrains any tendency for the key to rotate under load.
There is a slight increase in leverage when raising a cover from one end,
and, if the cover is inadvertently dropped, the feet will be further away
from the danger area, because of the length of the lever. One end of the
handle is chisel shaped to facilitate removal of dirt from the keyhole and
from the channel prior to replacement of the cover.
3. Method of use
The lower picture shows
the key in use. The cover keyhole should be cleared of dirt and the key
inserted and rotated 90 degrees.
When the cover is difficult to lift
(sealed) the key should be detached from the lever, reversed and refitted.
Then, by using the key with the front end pad positioned outside the frame the leverage so obtained can be used to 'break the seal'. The
key should then be returned to its normal position.
