=34. Locks in General.=—In no other line of hardware is there such a
variety of grades and types as there is in door locks. In general,
locks may be designated as _surface_ and _mortise locks_, the former
being secured to the surface of the door and entirely exposed to
view, while the latter are let into a mortise cut in the edge of the
stile. Besides these two general kinds of locks, there are several
special locks, which will be fully explained. As to quality, locks may
be classified in three grades; namely, _common_, _medium_, and _high
grade_.
[Illustration: FIG. 36]
[Illustration: FIG. 37]
=35. Common-Grade Rim and Mortise Locks.= The =rim lock=, as
illustrated in Fig. 36, is generally used for buildings of the
cheapest class, such as tenements and small houses. As cheapness is
the controlling factor in such goods, especially the goods made for
speculative building purposes, the quality diminishes with the price.
For cheap work, rim locks are used on account of their low cost and
because they are easily applied. They also require no trim, such as
escutcheon plates, etc., and are complete when the spindle and the knob
are furnished with them. Rim locks are made in various sizes and either
square or rectangular in shape, the long dimension being placed either
horizontal or upright. They may also be obtained with either iron or
brass bolts, and are furnished with iron, tinned, or nickel-plated
keys. The cheapest grades of rim locks are made with two bolts and one
tumbler, while the better grades have an additional stop and a slide
bolt with three tumblers.
Rim locks are generally constructed of cast-iron, and in selecting
them, a careful inspection should be made of the internal mechanism,
choosing only those rim locks in which the bolts and the tumblers are
constructed of steel or brass. Rim locks, however, are also made of all
steel, and these are coming into general use. They present a somewhat
better appearance than cast-iron locks, as may be seen from Fig. 37.
The cast-iron rim lock may also be obtained with an ornamental case.
These cast-iron cases, as a rule, are finished in imitation of bronze.
Such rim locks, however, are not in general use on account of their
somewhat higher cost, and from the fact that their appearance is not
greatly improved by the ornamentation.
[Illustration: FIG. 38]
=Cheap mortise locks=, or =sets=, are also largely used for the more
common grades of work. They are sold in sets, that is, with escutcheon
plates, etc. of steel or cast-iron, both in plain and ornamental
designs, as illustrated in Fig. 38. The cheapest lock sets are fitted
with pottery knobs, and the better grade, with metal knobs. All of
these locks described are of poor construction, as quality is a
secondary consideration.
[Illustration: FIG. 39]
=36. Medium-Grade Mortise Locks.=—The locks grouped under the term
“medium-grade” hardware have been greatly improved in recent years and
are adapted to a large range of uses, but they are especially made for
residence work. In dwellings of the better class, the best types of rim
locks are used for doors in attics and basements, and for closet doors,
but for all other doors, the =medium-grade mortise locks= are used.
These locks are provided with cast- or wrought-bronze lock fronts, are
made with from one to three lever tumblers, and have drop-forge steel
cases. The locks are constructed with easy springs, which allow the
latch bolt to retreat within the case on one light spring when the
door is closed, and when the knob is turned, to operate the latch,
both springs act jointly in order to overcome the friction of the knob
and to throw the bolt back to central position. The mechanism of an
easy-spring, mortise knob lock is illustrated in Fig. 39.
[Illustration: FIG. 40]
In the group of locks embodying those of medium quality are included
the three-bolt locks used for chamber and exterior doors, locks for
communicating doors between chambers, and twin, or two-bolt, locks
for twin bathroom or toilet-room doors, these being respectively
illustrated in Fig. 40 (_a_), (_b_), and (_c_). All of these locks
should be used with wrought- or cast-bronze trim, either plain or
in design, and in finishes to suit. Locks for exterior doors, where
security is important, should be selected with this object in view, and
three-tumbler, or three-bolt, locks should be used.
=37. High-Grade Locks.=—There are a number of high-grade door locks and
latches in the market for the equipment of first-class buildings, and
frequently these locks are especially constructed to meet particular
requirements. Among such locks are included, besides high-grade,
three-tumbler locks, those that embody the cylinder principle and those
that are equipped as master-key locks.
[Illustration: FIG. 41]
The =unit-cylinder lock=, illustrated in Fig. 41, is made by P. & F.
Corbin. This hardware specialty is a new departure in lock making. The
mechanism of the lock is contracted into the smallest possible space,
occupying only about 1½ in. × 3¼ in. Instead of being mortised into the
stile of the door, as is usual with the mortise lock, a piece is cut
entirely from the stile, as illustrated in Fig. 42. In order to prevent
this operation from weakening the stile of the door, the unit-cylinder
lock is provided with heavy escutcheon plates that are strongly ribbed
on the back, so that when these plates are secured to the stile at the
top and bottom, they supply the rigidity necessary to make up for the
notching. As the name implies, these locks are made in a unit, and the
keyhole to the cylinder lock is located in the knob. The unit-cylinder
lock is made in two styles—with dead-locking latch bolt and with
additional dead bolt.
[Illustration: FIG. 42]
=38. High-Grade Interior Door Locks.=—In Fig. 43 is shown a type of
high-grade, =mortise-locking latch= for interior doors. These locks
are of the heaviest construction, and are fitted with either brass
or bronze fronts. The bolts are operated with two or more tumblers
constructed on an improved pattern, and are of fine workmanship. The
trim for a lock of this character should be of the very best grade,
with knobs of the screwless-spindle type, which will be explained later.
The escutcheons should be of the high-collar or the bracket-bearing
type, and should conform to the character of the locks in quality
and finish. On the most important work, it is always expedient and
usually feasible to obtain expert advice from manufacturers or from
dealers representing the manufacturer, whose intimate knowledge of
the product will be of great assistance to the architect or owner in
making suitable selections. The use of high-grade hardware requires
a considerable expenditure, and the necessity for expert advice
consequently becomes more imperative if the best results are to be
obtained.
[Illustration: FIG. 43]
=39. Master-Key Locks.=—The type of lock known as the =master-key
lock= is generally used for public or office buildings, hotels, and
occasionally in the better class of residence work. These locks can
be grouped into two classes; namely, the _Yale_, or _cylinder_, and
the _lever-tumbler types_, the class first mentioned being the most
desirable.
In the lever-tumbler type, illustrated in Fig. 39, the tumblers,
or wards, are so arranged that each lock can be operated only by
its particular key, the keys for all rooms being different and
non-changeable; all of the locks, however, can be operated by a key
made for the purpose, termed a =master key=. Each lock of this type has
two sets of tumblers; one set is operated by its individual key, and
the other, being uniform in all locks of the series, is acted on by
the master key. Such locks may be obtained either in the cheaper kind,
with one tumbler and twelve changes, or in the most intricate styles
of hotel locks, with five tumblers and 48,000 changes in one set, and
all operated by one _master key_. The cylinder lock of this type is
illustrated in Fig. 44, which shows a Yale & Towne, mortise, front-door
lock.
[Illustration: FIG. 44]
=40. Details of the Yale Type of Master-Key Locks.= The =Yale= type
of cylinder lock, which is illustrated in Fig. 45 (_a_) and (_b_), is
much preferred, on account of the great security it gives and the small
key required by it. This lock is made in three systems; namely, the
_regular_, the _concentric_, and the _paracentric_, or _duplex_.
In the =regular system=, one regular cylinder is controlled by the
change and master keys, the pin tumblers being cut in two places,
so that the change key brings one set of the abutting planes of the
tumbler in alinement with the surface of the cylindrical plug. This
plug is arranged so that a separate key is required to operate each
lock, the other line of cleavage through the blocks being the same with
all locks throughout the series, so that they may be opened with the
same key.
[Illustration: FIG. 45]
[Illustration: FIG. 46]
The =concentric cylindrical arrangement= of this type of lock is shown
in Fig. 46 (_a_) and (_b_). Here, there is a larger cylinder encircling
the key plug. This is known as the master-ring, or larger, plug, and is
indicated at _a_. When the change key is inserted in the key plug _b_,
the lower series of breaks in the pins comes into alinement with the
outer edge of the plug, as shown at (_a_), and allows it to revolve in
the master ring, the cam on the inner side at _c_ actuating the lock.
When the master key is inserted, the upper series of breaks comes into
alinement with the outer edge of the master ring, as shown at (_b_),
allowing the plug and the ring to rotate together with the turning of
the key, and thus to produce the same result as that caused by the
operation of the change key.
[Illustration: FIG. 47]
The =paracentric system=, sometimes called the _duplex system_,
consists in having two separate cylinders to each lock, as illustrated
in Fig. 47. One of these cylinders, generally the upper one, is
operated by the change key, and the lower one, by the master key.
The interior construction of the lock is so devised that each key
performs the necessary function of operating the same bolt, so that
the individual lock may always be opened by the change key, and all
locks of the series by the master key. This latter system of lock
construction is more expensive than the one-cylinder type, but it
possesses an advantage in that it provides greater security when a
limited number of locks are grouped in one series.
=41.= Owners or officials of large office buildings and industrial
works now avail themselves of the master-key system just explained.
They are able to obtain mortise locks, rim locks, and padlocks,
all arranged to operate with a master key, in one series. In fine
residence work, this system is also adopted. Such a system of locking
is easily recognized as convenient, especially where subordinates
are held responsible for certain rooms or departments to which they,
individually, have access, as all of the rooms or departments may be
entered by the manager or superintendent by the aid of the master key.
A series of master-key locks may also be “submaster-keyed” by dividing
it into subordinate groups. In such a case, each group is operated by a
master key of its own, and all the subordinate groups are controlled by
a grand master key. For example, a six-story office building could be
furnished throughout with locks having non-changeable keys; the doors
of each floor could be operated separately by a master key; and the
doors of the entire building could be operated by a grand master key.
The convenience of such a system is readily apparent in large buildings
where each janitor is responsible for a certain floor, and where the
head janitor, manager, or owner, has control of all the locks through
the grand master key.
In some instances, for additional security and for special work,
the corrugations in the keyway are changed in shape so that the
manufacturers’ regular type of key will not enter the keyway, or plug,
thus allowing no chance for the regular type of key to operate the
lock.
=42. Locks for Residence Use.=—The =front-door lock= is distinctly a
lock having two bolts; namely, a _dead bolt_ and a _latch bolt_. The
latter is operated by the knob, and is so arranged that, by means of
stop-work in the lock front, the outer knob may, at will, be set so as
not to operate the latch, the latch bolt being operated only from the
outside by a key.
[Illustration: FIG. 48]
The cylinder type of front-door lock illustrated in Fig. 44 is the best
lock for this purpose, as it provides the greatest security. This lock
is operated by a convenient key of the Yale type, which throws both
latch and dead bolt with one insertion into the cylinder.
Three-tumbler, front-door locks and latches are to be had at a low
cost, and are used in the cheaper class of dwellings. When the
residence has an inner, or vestibule, door, a similar lock is used
without the dead bolt; this lock is termed a _vestibule latch_. In all
cases the vestibule lock should “key-lock” with the front-door lock, so
that one key will operate both. The other exterior doors of a residence
should have either Yale locks master-keyed to the front door, for the
better class of work, or locks of the 5-inch, three-bolt variety, that
are furnished with an extra bolt in addition to the dead bolt, the
third bolt being operated by a thumb knob on the inside. When a cheaper
trim is wanted, a 4-inch, two-bolt lock, supplemented by a separate
mortise or rim bolt, may be used.
For the first- or parlor-floor folding doors, 4- or 4½-inch, two-bolt,
mortise locks are ordinarily employed. Where the doors are sliding,
a 5½-inch, sliding-door lock with dead bolt and pull, or handle,
is provided. The pull, or handle, is operated, or thrown out, when
needed by pushing a button, or stop, in the lock. This special type of
sliding-door lock is illustrated in Fig. 48.
For bedroom doors, a lock similar to that used on the minor exterior
doors is usually employed. The lock for these doors may be either a
5-inch, three-bolt lock, or a 4-inch, two-bolt lock supplemented with a
mortise bolt. For communicating doors, it is best to use a three-bolt,
knob lock, the latch bolt of which is operated by the knob from either
side. Arranged above or below this latch bolt are two dead bolts, each
being operated by its respective thumb piece on opposite sides of the
door. Locks of this character are made for both swinging and
sliding-doors.
=43. Locks for Twin-Closet and Other Interior Doors.=—Twin, or double,
doors are sometimes used between rooms in residences to deaden sound
or to increase privacy. Such doors should be fitted with the same type
of lock as other communicating doors, except that the lock should
be provided with two bolts, the same as the lock used for bathroom
doors. These locks are arranged with special trim on the abutting
face of each door, this trim having only a slight projection, and
knobs or lever handles projecting as little as possible, in order to
avoid interference on account of the limited space between the doors.
Bathroom doors are best fitted with a thumb bolt, either combined with
a lock or separate.
In fitting closet doors, it is best to use a two-bolt lock about 4
inches in size, with trim on both sides, so that the door may be
operated from inside in case it is accidentally closed on a person in
the closet. The possibility of this happening is slight, and usually a
saving is effected by using a knob latch without a dead bolt and a pair
of knobs with roses.
For basement or attic doors, a cheap type of mortise lock is
appropriate, or a rim lock may be used, if cost is a consideration.
Where care is exercised in the selection of locks in any one building,
great convenience will result from having all the different class
of locks about the building of the same grade, so that they may be
master-keyed in one set and thus give the owner control, with one key,
of all the locks. Each lock, however, will have its own individual, or
change, key, and should be selected and ordered with this object in
view. Another convenience may be had by ordering each room and closet
door keyed alike throughout the house, or alike throughout each floor,
so that the loss of a key will cause little or no inconvenience.
=44. Hotel and Office Locks.=—The purpose and use of master-keyed
locks has already been explained, but the employment of such locks
in large groups, as in the equipment of hotels and office buildings,
requires further discussion. The term _corridor door_ designates the
entrance from a corridor or a hallway to a bedroom or an office, while
_communicating doors_ are those between adjoining rooms. Frequently,
these doors are double, and are then known as twin doors, while the
term _closet doors_ is self-explanatory. Each of these doors requires a
_knob lock_; that is, a lock having the latch bolt operated by the knob
and the dead bolt operated by a key. Sometimes, in the case of locks on
closet doors, the dead bolt on communicating-door locks is omitted, and
a thumb bolt substituted. While all of the locks thus far enumerated
are used in hotels, and most of them in office buildings, technically
speaking, a _hotel lock_ is a master-keyed knob lock for doors from
the corridor to bedrooms, while an _office lock_ is an inverted lock;
that is, a lock with the keyhole above the knob. These latter locks are
usually master-keyed, especially for the doors from the corridor to the
office. Such locks as these may be master-keyed on any of the systems,
as previously explained. For office work, a small key is desirable,
so that cylinder locks are ordinarily employed, as the key for the
operation of such locks may be conveniently carried. For hotels,
however, a high-grade lever-tumbler lock with round, substantial keys
is desirable, because the keys are liable to hard usage, and should not
be convenient to carry in the pocket.
Hotel keys vary widely in arrangement, as well as in size, quality, and
price. The kind of action, or mechanism, to be adopted in a hotel lock
is frequently determined by the preference and experience of the hotel
manager, and it is desirable that he should be consulted in advance;
but the location and use of each door should be considered in the
selection of the locks for this character of building. It will thus be
seen that the subject of hardware for a hotel is one that requires the
most careful consideration of the architect.
The grouping of locks in a hotel should be studied, and, usually,
the best plan in large hotels is to group all of the locks on each
floor under one master key and to provide a different master key for
each floor, care being taken to limit the issue of master keys to the
smallest possible number of responsible persons. In some cases, a grand
master key is also provided that will open all the locks on every
floor. This arrangement of the locks entails an additional expense,
and also has the disadvantage that, in case the grand master key is
lost, all of the locks controlled by it should at once be set to a new
combination, in order to prevent access by the person into whose hands
the key has fallen. This procedure is both troublesome and expensive.
[Illustration: FIG. 49]
The foregoing remarks relating to hotel locks apply equally to office
locks, especially as to the arrangement for the operation with the
master key. In other respects, however, the locks for an office
building differ considerably from those used in hotels, for a hotel
lock must secure the door both when the room is occupied and when it
is not, whereas an office lock is used chiefly to secure it when not
occupied. In consequence of this, certain differences in action are
employed. All office locks have a latch bolt that is operated by the
knob from both sides and yet permits free ingress and egress. Various
methods, however, are employed to lock the door against ingress
except by means of a key. Sometimes this is accomplished by means of
a separate dead bolt operated by a master key from either side; in
other cases it is accomplished by a latch bolt only, by providing the
latter with a stop-work like a front-door lock. By this arrangement,
the outer knob may be stopped so that the latch bolt cannot be operated
from the exterior except by the key; and, again, the latch bolt
may be dead-locked from the outside by the key. The choice of these
arrangements is a matter of personal preference.
=45. Store-Door Trim.=—The technical term =store-door lock= originally
designated a heavy rim or mortise dead lock, but is now applied to a
combined lock and latch, the former being operated by a key from either
side, and the latter by a thumb piece located above the pull handle.
Such locks are made in a large variety of sizes and styles, the best
being of the cylinder type, as shown in Fig. 49. In this lock, the
latch is operated by the thumb piece during the day, while the dead
latch secures the door at night.
Plates and handles for the combined store-door lock and latch are also
made in many sizes and styles, from the plain rectangular type to the
most ornamental forms. Such trim offers good opportunity for effective
decoration, and no embellishment is so effective for a store’s entrance
door as a pair of handsome plates and handles of appropriate design.
For such trim, it is not uncommon to provide an outlay of from $25
to $30 per door. Some of the more elaborate store-door handles are
illustrated in Figs. 50 and 51. The trim illustrated in these plates
is very carefully selected by the architect to match the style of
architecture in which the building is designed, and the finish is
selected with as much care.
=46. Padlocks.=—While =padlocks= are not ordinarily included in
builders’ hardware, they are extensively used for factories, stables,
and other buildings of this character; thus some care should be taken
in their selection. Padlocks are made in a great variety of sizes,
styles, and qualities, and retail at prices ranging from 10 cents,
or less, to $5. Where these locks are exposed to moisture or to the
weather, they should be of bronze or of brass, with all of the interior
construction of the same material. If required for great security, that
is, for places where they are likely to be subjected to violence, they
should be very heavy, and preferably provided with steel shackles.
Padlocks constructed on the cylinder-lock principle may be obtained,
and should always be used where a series of locks that are operated by
separate keys and controlled by a master key is employed. Ordinarily,
a selection of padlocks should be made only after an inspection of the
actual samples, and not according to catalog representations.
[Illustration: FIG. 50]
[Illustration: FIG. 51]
=47. Cabinet Locks.=—The locks used in cabinetwork are distinct from
builders’ locks, though they are occasionally used in the construction
of the finer classes of interior finish, and, consequently, are of
interest to the architect. =Cabinet locks= are made chiefly of wrought
metal, and in a vast variety of kinds, sizes, and grades, so that care
should be exercised in their selection. The leading kind of cabinet
locks are drawer, or till, locks; wardrobe, or cupboard, locks; and
chest, box, and desk locks. Special locks are also manufactured for
many other purposes. For the best work, the Yale, or pin-tumbler, type
is desirable where great security is required, but for ordinary uses,
other types, with either flat or round keys are available. Many of the
cabinet locks admit of being master-keyed, and such locks are employed
on lockers in club rooms, armories, etc.
[Illustration: FIG. 52]
=48. Asylum and Prison Locks.=—For the doors of cells in insane
asylums, hospitals, and prisons, locks of special construction
are required. For this reason, a distinct class of hardware is
manufactured to meet the peculiar conditions that prevail. These
locks, which are designed primarily to prevent escape from the rooms,
or cells, are exceptionally exposed to attempts at tampering, and are
especially constructed to meet these conditions. There is an extensive
line of locks for these uses on the market. This line includes both
the Yale type and the lever-tumbler type of lock, and these locks are
constructed with both solid and barrel keys, thus affording a wide
range of selection. All such locks must be made so as to be controlled
by master keys.
In Fig. 52 are illustrated types of prison or asylum locks. The lock
shown at (_a_) is embedded, or built, in the jamb, while that at (_b_)
is secured to the door and the keeper is fastened in the jamb.
[Illustration: FIG. 53]
There are numerous other patterns of asylum and prison locks, such as
those illustrated in Fig. 53. The lock shown at (_a_) is arranged to
operate with a double-bitted key, while the one at (_b_) is operated by
means of a Yale key.
Nearly all modern locks for this purpose are operated with either
double-bitted or Yale keys, and those in common use are cylinder locks.
Information regarding these types of locks should be obtained in
advance, so that in preparing the plans and specifications, the type
selected may be clearly indicated and the arrangements made for any
special construction necessary to receive them. As the approved forms
of asylum or prison locks are built in the masonry during construction,
they must be delivered during the early stages of the erection of the
building.
=49. Bank and Safe Locks.=—Locks for the doors of burglar-proof and
fireproof safes and vaults constitute a group distinct from all others.
These locks embody the most complicated mechanism, and represent the
highest art of modern lock making. The architect in preparing plans
of buildings for banks and trust companies is frequently called on to
approve or to specify the fastenings for vault and safe doors. While
the owners of such buildings will probably predetermine the kind of
lock to be employed, nevertheless they will be guided by the advice
of the architect in the selection of some particular make. The locks
used on such vaults and safes comprise _time_, or _chronometer, locks_;
_dial_, or _combination, locks_; and _safe-deposit_ and _subtreasury
locks_. There is also a device known as a _bolt-motor_, or _automatic
lock_, which is an allied product. In the manufacture of these special
locks, the skill of numerous experts and specialists is required, and
as their knowledge is at the disposal of the architect or the engineer,
they should be consulted in the selection of such important pieces of
mechanism.
[Illustration: FIG. 54]
The =time lock= is illustrated in Fig. 54, and is a locking device
actuated by clockwork. This type of lock is used in connection with
the heavy boltwork of a safe door, to prevent it from unlocking
except during certain hours determined beforehand. This lock is now
recognized as an essential part of the equipment of all first-class,
burglar-proof vaults and safes. In its standard form, the time lock has
three chronometer movements of the finest construction, each of which
is competent to actuate the lock, so that, in this way, almost absolute
reliability is insured.
[Illustration: FIG. 55]
A =dial=, or =combination, lock= is shown in Fig. 55. The combination
commonly called the _dial lock_ has completely superseded the key lock
for use on safe and vault doors. Essentially, the dial lock consists of
a bolting mechanism guarded by a set of changeable tumblers, or wheels.
These tumblers are actuated by a spindle passing through the door,
this spindle being provided on the outer end with a graduated dial.
By rotating the dial in a certain manner, the dial can be set and the
lock operated. Dial, or combination, locks are made in two grades, or
varieties, designed respectively for burglar-proof and for fireproof
safes. The lock intended for burglar-proof purposes is heavy and made
to resist violence, while the other locks are smaller, simpler, and
cheaper, intended only to secure the door against ordinary intrusion.
Both of these locks should be absolutely “non-pickable.”
In connection with the time lock, an automatic bolt-operating device
is now used on burglar-proof safes. The =bolt-motor= is a mechanism
containing heavy springs and is attached to the inside of a safe door.
These springs are set, or braced, while the door is closed, and when
released by the action of the time lock are capable of automatically
retracting the heavy boltwork of the door. This construction obviates
the necessity of any spindle through the door, and leaves the surface
absolutely unbroken, without any communication between the interior and
exterior.
[Illustration: FIG. 56]
A form of =safe-deposit lock= is illustrated in Fig. 56. This lock
is of a new type, and is intended expressly for individual safes, or
boxes, rented by the safe-deposit companies. Such locks are nearly
always provided with a guard key, which is in charge of a custodian
and common to all the locks in the series. Each lock has its own
individual, or change, key, however, which differs from every other
key in the series. Before a change key can be inserted into its lock,
the guard mechanism must be unlocked by the guard key in charge of
the custodian. This makes the presence of the latter a necessary
preliminary to the unlocking of the box by the renter or his authorized
agent. Many styles and sizes of safe-deposit locks are made to meet
varying conditions, the lock probably most used being the Yale, or
pin-tumbler, variety, in which additional security is obtained by using
keys of special proprietary forms. For safe-deposit boxes of large
size, the dial lock is often used.
=Subtreasury locks= are intended for use on the small safety chests,
or “subtreasuries,” often placed within a fireproof safe. These locks,
which are illustrated in Fig. 57, are of various types and sizes, and
are suitable for use on metal doors of all kinds.
[Illustration: FIG. 57]
=50. Care and Maintenance of Locks.=—Locks, like other pieces of
mechanism, need reasonable care and attention to keep them in the
best condition. As they contain moving parts, they are subjected to
frictional wear and need occasional lubrication. Most of the friction,
and consequently the wear, occurs in the beveled latch bolt, which
may be readily lubricated. If the latch bolt is troublesome, its face
and back should be cleaned with a cloth moistened with naphtha or
kerosene, to remove any dirt. These surfaces should then be wiped with
another cloth saturated with machine oil or, better, with vaseline. Any
person can perform this simple work, and if it is done once or twice
a year, it will keep the bolts in such condition that each door will
close easily and quietly at all times. Another cause of trouble is the
tendency of the old-fashioned knob screw to become loose, thus allowing
the knob to pull from the spindle. Where such spindles are used, it
is a good plan to inspect them occasionally and to tighten any loose
screws. The best results from lock hardware, however, can be obtained
by having all locks and hardware inspected by a lock expert about once
a year.
=51. Pottery Knobs.=—=Door knobs=, which are important appurtenances
to locks and latches, are made of many kinds of materials, and are
fastened to the spindle in several ways. It is necessary, in order
to make the proper selection of knobs for doors, to be thoroughly
conversant with the various types on the market. The cheapest type of
door knob is molded from several kinds of clay. These =pottery knobs=
are secured to iron or bronze shanks by _leading_; that is, by setting
them in molten lead, which, in hardening, secures the knob to the shank.
[Illustration: FIG. 58]
Pottery knobs are made in three styles, namely, _mineral_, _jet_,
and _porcelain_. Mineral knobs are dark brown in color, while jet
and porcelain knobs are, respectively, jet black and pure white.
All of these knobs are highly glazed, and are used only with the
cheapest grades of locks. Ordinarily, they are furnished with japanned
mountings, or shank and rose; occasionally, however, they may be had
with bronze-plated, real bronze, or brass mountings. The several styles
of porcelain knobs are illustrated in Fig. 58. At (_a_) is shown the
mineral knob, while at (_b_) and (_c_) are shown the porcelain and jet
kinds.
=52. Wooden Knobs.=—Knobs made of wood are quite generally used.
They are always turned from some hardwood, and are either stained or
finished naturally. The wooden knob is usually forced on the shank
by hydraulic pressure, and when securely fastened in this way makes
a desirable and cheap knob. Many of the cheaper wooden knobs on the
market are only glued or cemented to the shank, and, consequently, are
not durable, as they pull off; they are therefore entirely undesirable.
The mountings for the better knobs are made of iron, brass, or bronze,
though they may be had with wooden roses. Mountings of wood, however,
should not be used, as any severe side strain on the knob will split
the rose with the grain of the wood. In Fig. 59 are shown two wooden
knobs, the one at (_a_) having a metal rose, and the one at (_b_) a
wooden rose.
=53. Cast-Iron Knobs.= Cheap locks are usually provided with knobs
made of cast-iron, and, although they are strong and serviceable, they
are seldom attractive. For finishing knobs of this kind, a bronze
metal plating is usually employed. Cast-iron knobs are frequently made
ornamental instead of plain. A typical cast-iron knob and rose are
shown in Fig. 60.
[Illustration: FIG. 59]
[Illustration: FIG. 60]
=54. Stamped and Spun-Metal Knobs.=—Knobs made of sheet metal have
lately come into extensive use, and they may be obtained in a large
variety of designs and forms. Plain and ornamental steel knobs are
illustrated in Fig. 61. Knobs ornamented in any style of design are in
the market, and are artistic and usually well modeled.
[Illustration: FIG. 61]
=55. Bronze or Brass Knobs.=—Knobs of bronze or brass are always used
in buildings of the better class, and all ornamental knobs of the
higher grade are made of these materials. The best knobs are usually
solid; that is, cast in one piece, with the exception that the shank
is inserted. Others are made in composite form, consisting of a steel
interior shell, or frame, over which is tightly drawn an external
section, or covering, of wrought-bronze or brass of substantial
thickness. The completed knob, if properly made in this manner, is
practically as strong as the hollow-cast knob and resists bruising or
other injury.
=56. Glass Knobs.=—The most expensive knobs made are those of cut glass
with metal mountings. Several knobs of this kind are illustrated in
Fig. 62. Cut-glass or crystal-glass knobs are very costly, the price
depending on the style and the amount of cutting required and on the
grade of glass used. The new method of mounting glass knobs allows for
adjusting the knobs to doors of varying thicknesses, and also gives the
knobs a handsome appearance, making them both durable and reliable.
=57. Styles and Sizes of Knobs.=—The pottery knobs, such as the
mineral, jet, and porcelain knobs, are made only in spheroidal and oval
shapes. The spheroidal knobs are 2¼ inches in diameter, and the oval
knobs 2½ in. × 1¾ in.
Cast-iron and stamped-steel knobs are made spheroidal and of the box
pattern, with plain and molded edges, both styles of knobs being about
2¼ inches in diameter.
Bronze and brass knobs are usually spheroidal or ball-shaped, and are
2¼ and 2½ inches in diameter. They are also made oval and egg-shaped,
these latter styles being provided in two sizes, namely, 3 in. × 2 in.
and 2½ in. × 1¾ in. The same general dimensions obtain for wooden and
glass knobs.
[Illustration: FIG. 62]
=58. Lock Spindles.=—In supplying a pair of knobs, there is always
included with them the _spindle_, which connects them and passes
through the hub of the lock. The type of spindle generally used is the
=common=, or =side-screw=, =spindle=, which is shown in Fig. 63. In
this spindle, the knobs are secured by means of a knob screw passing
through a hole in the knob and engaging with one of the threaded holes
in the spindle. There are several holes in the spindle, so that the
distance the knobs are apart may be adjusted properly. Should further
adjustment be required, it is accomplished by placing thin washers at
the end of the knob shank. This type of spindle is generally used with
the cheap grades of trim, and should not be used in high-grade work.
[Illustration: FIG. 63]
There is a modern type of lock spindle, known as the =“screwless”
spindle=, that permits the proper adjustment of the knobs without
the use of washers and with less screws. These spindles overcome the
general looseness and rattle found in the common type. A “screwless”
spindle, known as the _Triplex_, is illustrated in Fig. 64. This
spindle is a first-class device, and is constructed, as shown, of three
parallel parts, triangular in section, which, together, form a square
bar. To fasten the knob on this spindle, a setscrew in the knob bears
on the center bar, and owing to their wedge form, the two side bars are
forced apart and into frictional engagement with the spindle of the
knob. The spindle itself is screwless, and there is nothing tending to
loosen the setscrew, so that when once properly tightened, the knob
will remain firm and in position on the spindle under all conditions
of use. In some instances, this style of spindle has been condemned by
owners and architects. This has been due largely to the fact that the
mechanic did not set the screw tight against the spindle, thus allowing
the knob to be easily pulled off. This is often caused by not using a
screwdriver that exactly fits the head of the screw. When the knobs
are put in place as they should be, this device always gives entire
satisfaction.
[Illustration: FIG. 64]
[Illustration: FIG. 65]
There is another, though somewhat costly, type in the market, known as
the =wrench spindle=. This spindle is illustrated in Fig. 65. As shown,
the mechanism consists of a chuck, or vise-like arrangement, formed
on the knob shank. When the nut _a_ is screwed on the jaws _b_, the
tendency is to grip the spindle securely, the latter being solid and
without screw holes. This type of spindle allows perfect adjustment.
Another type of knob spindle is the =swivel spindle=. This is used with
front, vestibule, and other door locks that have stop-work, whereby the
outside knob may be made operative or not, as desired. In order to
accomplish this, the spindle is divided longitudinally, so that one end
may rotate independently of the other.
The standard sizes of spindles for door locks, etc. are ₅/₁₆ and ⅜ inch
square. Occasionally, spindles as large as ½ inch square are used for
large knobs or handles, such as would be used with massive lock trim.
For thumb knobs and locks and latches of this character, spindles ¼
inch square are employed.
=59. Key Tags for Hotel Use.=—Considerable confusion is frequently
created by hotel guests taking with them on departure the key to their
rooms. Formerly, hotel managers sought to prevent this practice by
attaching to each key a large tag of iron or brass, generally serrated
on the edges and made so cumbersome as to practically preclude its
being carried in the pocket. Subsequently, tags made of red fiber of
large size became popular. The usual forms of these large tags, whether
of brass or fiber, are illustrated in Fig. 66. The use of key tags,
however, is gradually being superseded by having the name of the hotel
and number of the room stamped plainly on the key bow, the stamped name
of the house serving for its quick identification and return by mail.
The latest and best development in this detail consists in attaching
to the key bow, by means of a short chain, either an ornamental disk
bearing the name of the hotel and the number of the room, or a small
ball, the name and key number still being retained on the key bow. In
either case, the short pendant serves for convenience in the use of the
key, diminishes the danger of misplacing it, and, if well designed,
contributes to its appearance.
[Illustration: FIG. 66]