Rev. A.3, 5/00 Page- 12
In the case of very tall an d l arg e g ates , a l evering p rob l em can exist. By t h is we mean th at an
intruder may be able to flex the gate enough to take up the slack in the strike mounting screw
and then lever of f th e strike p late. If th e instal ler or user d etermin es th at th is may h appen , a
single Magnalock will not provide adequate security and two must be used, typically at the top
and bottom of the gate.
Figure 11 (above) shows preferred special techniques for Magnalock mounting on 3 types of
gates. The f irst d rawing shows a single swinging gate. The general technique follows the
principl es discussed above but the use of Sec uritron's Z bracket wh ich creates a neat
installation is also shown. Note that in some cases, the post which moun ts the magnet is
hollow. It is possible to use the "F" version (without conduit fitting) and pull the wires through
the post wh ich may yield a neater and m or e s ec u re install ation.
The second drawing shows a double swinging gate which presents a unique problem. The
Magnalock is mounted in the same general way as on a single swinging gate but since both
arms move, an intruder p ushing on th e gate exerts a shearing f orce on the Magnalock.
Electromag nets are not at all strong in this orient ation of attac k. Therefore, as the drawing
shows, Securit ron's Z bracket sh ould be u sed with an in terference piece wh ich blocks t he
shearing effect while the strength of the magnet blocks one arm moving while the other is
stationary. For this technique to work, the motorized operator must be coordinated which
means that one ar m mu st move first to c l ear th e in ter feren ce p iece b ef ore th e oth er arm s tart s
moving. Gate op erators can n ormally accomp lish th is.
The final drawing on Figure 11 shows a special mounting technique for sliding gates. We
recommend t he use of the "GF " type magnet and two 3" angle brack ets (available f rom
Securitron ) for a neat instal l ation . A special s trik e mou nt in g t ech n iqu e is s hown in th e d rawin g
which improves reliab ility. The probl em is that if the st rike is moun ted norm ally to t he ang le
bracket and the gate is a powerful one which slams shut, the magnet may be impacted to the
point where its mounting screws loosen or the bracket bends. The strike mounting technique
that is sh own c reates a "sh oc k ab sorb er" eff ect b y th e u se of l ock nu t s at t h e rear of th e st rike
and the rear of the bracket together with a spring. A through hole (rather than tapped) is
drilled in the angle bracket mounting the strike and extra long roll pins are used. When the
gate closes, the strike moves in ag ainst th e s p ring whic h is the shock ab sorbing ac t ion.
2.7 USE OF DRESS COVERS
Once the physical install ation is complete, you may want t o consider the use of a dress cover.
Dress covers are metal s tampings which slip over the magn et body and are affixed wit h
permanent double stick tape (supplied). The dress cover accomplishes three functions: First,
it makes for a more attractive install ati on by concealing the strike plate and mounting holes.
All that is seen is an attractive rectangular form on the door. Second, the cover provides an
extra degree of tamper proofing and finally it allows easy alteration of the fin ish for
architectu ral compatib ility. Dress c overs ar e avail ab le in clear al uminum , satin bl ack alu m in um,
polished stainless and pol ish ed b rass finishes.
Double d r es s c overs ar e al so available for in stallati on s on doub le doors. In this case, the c over
fits over two locks so long as they are not separated by more than 2" (50mm). Double dress
covers have all th e ad vantag es m ent ion ed ab ove and in ad dit ion pr od uc e th e app earan ce of a
single device which inside is really two. Consult the catalog for dress cover part numbers.
2.8 TAMPER PROOFING THE MAGNALOCK
In situations wher e vandal ism is expect ed, th e Magn al ock s hou l d be p r otect ed from tamp erin g .
The magnet itself is inherently tamper-proof being totally sealed. The magnet mounting screws
are vulnerabl e in that the m agnet can be dism ounted if the sc rews are loosen ed. The al len
holes on the screws can be filled with a potting compound, such as Devcon, or silicone.
Alternately, the entire hole in the magnet where the screw heads fit could be filled. Butyrate
caps are supplied to close the mounting holes. These provide some tamper proofing as they
can't be removed by hand, but can be pried out with a tool. Regarding the strike plate
mounting screw, it is covered by the strike when the magnet is energized. If tampering is
anticipated when the d oor is open, t he screw socket h ead may be fil led.
Another possib ility is that Secu ritron inventories special tamper proof screws for both
magnet an d strike mountin g. These screws are iden tical allen h ead types except that it
requires a special key to install and remove the screws. It is unlikely that a vandal would have
access to this type of key. Securitron optionally supplies the tamper proof screw sets with keys
both in the form of a manual allen wrench and in a bit key usable with a drill.