MANUAL – REFLEX EZ-TRAC™ | 25
diameter and designed to stop the assembly in the bit extending the
instrument past the drill string. The landing collar has an adjustable
steel spear point end which latches to the overshot. The opposite end
is threaded into the aluminium extension rod. The most common
application is wireline drilling with negative inclinations of
–90 to –45. The pin spear landing collar assembly is available in
standard drilling sizes.
15. Pin spear coupling
A pin spear coupling assembled with a landing collar is an alternative
to the pin spear landing collar assembly.
16. Landing collar
The landing collar is used together with a pin spear coupling. The
landing collar consists of a steel body with nylon landing collars and
spring. The nylons are size specific to the bit diameter, can be
interchanged with the steel body and are available for all current drill
diameters. The nylons are designed to stop the assembly in the bit
extending the instrument past the drill string. The spring absorbs the
impact shock as the collar lands in the bit.
17. Landing collar box type
The landing collar box type consists of a steel body with nylon landing
collars and spring. The nylons are size specific to the bit diameter, as
they are designed to stop the assembly in the bit extending the
instrument past the drill string. The landing collars have a box type
configuration which is threaded onto the overshot. The size of this
box thread is dependent on the overshot size (this could be a BQ or
NQ box coupling). Nylon can be interchanged with the steel body and
are available for all current drill diameters. The most common
application is wireline drilling with negative inclinations of –90 to –45
and for those who do not feel comfortable with latch type applications.
18. Brass Wireline Swivel
The swivel is made of brass. It must be non-magnetic as sometimes
the swivel is attached directly to the top coupling without any
aluminium extension rods, most commonly in open hole surveying
applications. The swivel has ball bearings, which prevents the
wireline from becoming tangled and twisted due to the ability to rotate
freely. Wireline is threaded through the eyelet and the cable is
crimped with special adapters to form a strong loop and knot. The
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