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___________________ 1
___________________ 4
THE GRAVITY ESCAPEMENT ___________________ 6
TO SET GLASS DIALS ___________________ 6
___________________ 7
GENERAL INSTRUCTIONS ___________________ 7
ELECTRIC RELEASE MOVEMENTS ___________________ 9
SYNCHRONOUS MOVEMENTS ___________________ 9
TOWER CLOCK ATTACHMENTS ___________________ 10
AUTOMATIC SILENCING DEVICES ___________________ 10
HAND SILENCING DEVICES ___________________ 10
ENDNOTES ___________________ 10





* * *
Power wound weight driven tower clocks are constructed with all weights, pulleys, motors, gearing and control switches built into them as a unit, the only parts not in the movement being the shafting to the dials, the dials and hands and the hammer for striking the bell with actuating chain.

The weight (or weights, depending upon whether the movement is for time only, time and strike or time, strike and chime) consists of several cast iron leaves bolted together, with pulleys at top and bottom.  There are also several loose leaves1 or adjusting weights.  Each weight is suspended by an endless chain which passes under the top pulley and hangs from two sprockets, one on the weight arbor of the train and the other on the winding-device speed reducer box.

The winding device lifts the weight when it reaches its lowest point of travel by drawing up the chain on the side which runs over its sprocket; at the same time the chain over the weight sprocket is held taut and is not raised. Thus the weight is raised without affecting the driving force on the clock train. The control switches, mounted in approved metal boxes on the floor plate at the back of the clock are tripped by the weight when it reaches the end of its downward or upward travel. This will be explained in detail further along.

Where the construction of the tower permits locate the movement near the center of the tower, also have the connections from hammer lever on the clock to the hammer on bell as straight and direct as possible. Often owing to the interferences in the tower it is necessary to locate the movement in an out of way place. In such cases our engineers should be informed so that they can furnish blueprints showing a recommended installation.

It is not necessary to locate the movement exactly at first as it can be put together and moved after complete assembly. With striking clocks, it is best to put in the rack, snail, rack detent and the small parts that go inside of the bed before the main wheels are placed. These parts must be handled carefully as they govern the striking of the clock and must not be bent. On the No. 15 striking clock the rack and rack detent are in one piece.

All parts, and especially the bushings and bearings should be cleaned thoroughly before being put together, and all bearings and parts that rub should be oiled with the tower clock oil2 sent with shipment.


To assemble the clock first place the floor plate in the desired position in the tower. Screw the supporting pillars into the floor plate. Mount the bed on the pillars and put on the pillar nuts. Next, bolt the back top frame in place. The back top frame is the one without the second dial.

The arbors are so arranged that they can be put on after the bed is in place and the top frames bolted on. The time arbors are shipped with parts assembled complete. The fly arbor has the fly detent on the front end, and the fly ratchet and fans on the back end. Note: The fly ratchet and fan can not be put on until the fly arbor is in position. Insert the back pivots of arbors into their respective bushings in back of frame and then put front top frame in place.

Next put on the top girt (or plate). The pallet and escape arbors should not be put in the clock until the top girt is in place. The escape arbor may be put in by removing the second dial from the front top frame and slipping the escape arbor through the hole from the back of the frame and then replacing the seconds dial. The pallet arbor, with pallets in place, should be put through the hole in the front top frame, the crutch wire slipped onto the arbor and the arbor placed in the hole in the pallet plate. The back pivot of the pallet arbor is carried in the sliding socket. Do not let the pallets come in contact with the escape wheel until the pendulum rod is in place.

The pendulum spring and fork should be put into the top girt and the washers and adjusting knob put on; the safety hangars and chops should next be put in place, and the pendulum hung.

To hang the pendulum, first put the cup (or ornament)3 on the rod from the bottom, and then slide the rod down through the ball and put on the nut. The nut at the bottom of the pendulum rod should be screwed up until the bottom edge of the nut is even with a scratch mark on the surface near the bottom of the pendulum rod. This will bring the top of the pendulum ball even with a pencil mark on the wood rod. (The cup or ornament on top of the ball must be raised to see this mark.) This will locate the ball in a position where the final adjustment can be made by the knob at the top of the pendulum fork, and when final regulation is made the pendulum pin will swing clear of the safety hangars. Wind the time weight by hand for a try-out, then add sufficient leaves to the time weight to give the pendulum the right motion.

If the clock is fitted with a Gravity Escapement the amount of weight does not affect the motion of the pendulum, but the weight should be sufficient to give the clock a prompt motion on the escape wheel and be able to drive the external hands.4 The bed of the clock must


be made to stand perfectly level to have the pendulum in beat; the clock is adjusted at the factory and will be correct if not changed before being put into place.

Should the floor of the clock room settle at any time, causing the clock to be out of beat, see that all screws about the escapement are tight, then put the clock in beat by turning the two knurled screws located near the top of the crutch piece, turning to right or left as necessary until the pallets are equally in beat on each side of the escape wheel and tighten both thumb screws against the crutch piece.

The lockwork levers are used to control the striking of the clock and are fastened to the bed by means of the lockwork stand. This stand is bolted to the left end of the bed. The end of the long lever rests on the lift cam on the minute arbor and when lifted by the cam raises the short lockwork lever, which controls the rack.

To set the strike train of the clock, turn the main strike wheel until the hammertail lever has just dropped off one of the cams on the wheel. Hold the strike train in this position and set the detent lever on the fly arbor so the projection on same rests against the projection on the lockwork lever, and fasten detent tightly on the fly arbor. With the train still held in this position, set the pickup, or gathering pins, on the second strike wheel arbor, so that one of the pins will have picked up a tooth in the rack and have passed far enough ahead to allow the rack to pass under it when the lockwork lever is raised to strike the next hour.

To set the clock to strike the correct hour in relation to the hands: Set the minute arbor on the time train so the lockwork lever just drops off the point of the lift cam, and with the minute arbor held in this position set both hands on the setting dial at 12 o'clock and the the hand on the seconds dial at 60; with the minute arbor still held in this position, loosen the snail bind knob so the snail will come out of mesh with the small pinion on the minute arbor, and set the snail so the rack detent pin will rest in the center of the lowest step of the snail; set the snail wheel back in mesh with the pinion and fasten with hand knob. Be sure snail bind knob is set up tight.

When the strike has once been set correctly in relation to the time train it is impossible for it to change its relationship.

Weight rests are furnished with all power wind movements. These should be placed on the floor inside the floor frame and the weight assembled on top of them. When assembling the weights see that all oil holes are up. These oil holes extend through the projection on the weights through the pulley stud and deliver the oil at the center of the pulley stud at the bottom side of the stud.

The chain should be passed over the smaller sprocket on the winding device gear box, under the upper pulley on the weight, over the larger or driving sprocket on the weight arbor, under one pulley on the adjusting lever, over the pulley on the bottom of the weight, under the other pulley on the adjusting lever and brought around so that the ends of the chain meet. These ends are connected with a special connecting link furnished with the chain.

After the chain is connected and any kinks removed, the adjusting lever should be lowered to take up the slack, and clamped tight at each end. Chain should be fairly slack, as too much tension will add to the load and may stop the clock.


The control switches operate by means of a brass rod extending upward from the switch handles through a hole in a square stud in each weight. Two brass collars with set screws slip over each brass rod. The positions of these collars on the rod should be adjusted to throw the switch in or out to the best advantage at the bottom and at the top of the weight travel. Small springs are furnished to be placed over the rod between the brass collars and the square stud. The upper spring takes up the additional travel of the weight after the current is shut off; the lower spring gives a slight additional fall to the weight in case the power should be off the instant the switch is thrown in. It also protects the switch handle from too great a strain.

Care should be exercised in setting the collars on the switch rod so that the switch throws in just an instant before the weight settles on the weight rests. Erect the clock and thoroughly test out the switch to be sure that it operates correctly before connecting power to the motors. Also make sure that motors are wired up to run the proper direction.

Standard motors of fractional horsepower are used. Be sure that the current supply agrees with the data as given on the motor plate, particularly as to voltage and type of current. Automatic overload cut-outs are provided for each motor, and should be wired into the circuit. It is preferred that the clock motors be connected to a circuit not used for any other purpose, as there is less chance of someone throwing out the switch.

Should the strike weight be allowed to run down, or the clock stops striking for any reason, it is not necessary to "strike the clock around," as with the ordinary house clock. Simply raise the rack up to the highest point, wind the weight and the clock will strike correctly at the next hour, provided of course that the time train has not been interrupted.


The clock must be so positioned that the center gear is set in the center of the tower5 in line with the centers of the dials and if the distance from the clock is short, gaspipe may be used for the leading-off rod connection, but if the distance is very much, tin tube must be used.6   If the distance is more than 15 feet, an intermediate bearing should be used with a set of universal joint couplings between each connection, the sliding part of the coupling to be set at the bottom. The connections considered correct for use will be sent.


To set the dial gearing in glass dials, loosen the set screws in the yoke and remove the shafts from the sleeve, remove the large nut from the sleeve and put on one of the metal plates sent and a rubber washer; place in dial from the outside and put on a rubber washer and a metal plate and tighten in place with large nut; the oil holes must be at the top. Care should be taken not to break the glass. Assemble the dial-works, making sure to leave a little end-shake in the shafts to allow them to run freely.

To set the dial gearing (motion works) in wood dials:  The motion works are designed for dials 1 3/4" thick and must be used with dials of that thickness.  If the dials are less than 1 3/4" thick, wood cleats should be put on the back of the dial where the motion works are placed to bring them up to thickness. If the dials are more than 1 3/4" thick they must be chiseled out to the correct thickness. The surface where the motion works go should be parallel with the outer face of the dial. Set the motion works with the oil holes up.

In setting the coupling on the dial connections the set screw on the two inner ends of the coupling should be placed in line, and the slide set hafway in the slot in which it works.

The conduit (tin tube) can be easily measured by placing one brass hub in the coupling on the dial gearing and one in the coupling on the center gearig and marking where the tubes come together; enough tube should lap over to make a strong joint when soldered.7

Setting the hammer: If the bell is in ringing mountings (i.e., is swung by a wheel and rope) the hammer should be set on the opposite side of the bell from the wheel and should strike through the bell frame. The hammer should be set to strike the bell on the sound bow (or thickest part of the bell) and be securely lag screwed to the floor or platform to withstand the vibration of the hammer on the buffer spring.

The buffer spring can be adjusted by nuts on the studs at the front and the back of the shoe, and the spring should be set to keep the hammer from striking a blow on the rebound after each blow by the clock.

As the leather pad on the buffer spring will harden and compress after a little use it will be necessary to adjust the spring, but after the leather has once settled into place it will not change enough to do any harm. If possible the hammer should be connected to the hammer lever on the clock on a straight line, but if this is not possible the chain guide pulleys can be used. Place one pulley directly over and in line with the clevis on the hammer tail lever on the clock and one pulley directly under and in line with the loop on the hammer lever. The pulleys must also be in line with each other.

The galvanized chain should be used to operate on these pulleys and the linked wire is to finish the connections.  The guards8 on the pulleys should be set to keep the chain from jumping out of the groove of the pulley when the clock strikes, and should not rub when the chain is under tension.


Care must be taken to have the chain and the pulleys perfectly in line to avoid any unnecessary friction.


The general arrangement can be seen from cuts in the catalogue, the escape wheel, fan and arbor are packed together and are assembled ready to put in the clock. The gravity arms should be hung on the short arbors from the bearings in the top girt and front top frame, the studs at the bottom of the arms should point out.

The pendulum furnished with this escapement is made to have zero coefficient of expansion, hence is not affected by temperature changes.


Plumb through the center of the dial opening and mark at the bottom of the opening and set the section with the VI directly over this mark. Fasten this section so it will be safe and put the next section on, and then install the section on the opposite side, etc. The XII section is to be set last, then bolt all sections securely, being careful not to "bulge" the dial frame. Plumb from the 12 o'clock through the center to the VI and fasten the dial to the building with the fasteners sent when it is plumb.

If there is more than one dial, all the frames should be set before setting the glass.

Each piece of glass is marked and should be placed according to these marks, as the glass is very irregular in shape and will fit only the section for which it is marked.

Set all outside sections of the glass first, using good putty or mastic9 cement. It is more convenient to set the bottom glass of each section first and fasten it in place with the brass angles. If it is impossible to get outside to place the hands, one section of glass may be left out until the hands are set.

In placing the center glass care must be taken not to force or cramp it as it will break from the effects of the cold if set too tight. If there are four dials to be set, it is best to set the glass on opposite dials, viz: first set the north dial and next the south dial, this reduces the wind pressure on the glass.

If the dials are in whole plate the hands may be set before putting the dial in place. Set the dial gearing as instructed, and put on the hands, set both hands to point to the (XII) and then set the dial in good putty and plumb through the XII and VI.



Strike a circle a distance from the outer visible edge of the dial to twice the diameter of the minute dots, to be divided into 60 spaces for the minute dots and another circle (4) times the diameter of the minute dots away from the outer edge of the dial to locate the inner edge of the numerals. Before spacing these circles, plumb through the center of the dial to locate the XII and VI and dividing from these points locate the minute marks.

The diamonds are to be used at the five minute marks and the ends of the diamonds nailed with brass nails to keep them from turning.

Round-headed brass screws should be used for both numerals and dots and holes should be bored for them before screwing in place; this is especially needed on dials covered with galvanized iron.

When attaching the dialworks to the back of wood dials see that the surface they are fastened to is flat and parallel with the face of the dial. Test this by putting on one of the hands and swinging it around the dial noting that the distance from the point of the hand to the surface of the dial is the same all around the dial, also see that the dialwork's minute arbor and hour hand pipe project through so that the hour hand, when placed in position, clears the dial and the numerals.

When standard wood or galvanized dials are furnished by the factory the numerals and the minute marks are all assembled to the dial plates.


Should the clock strike too slowly, first see that all bearings of the strike train, hammer connections and weight pulleys are free and thoroughly oiled; if the strike is still slow, either set the fans to give less resistance, or add more weight.

Should the leather pad on the hammer spring become compressed so as to allow the hammer to strike the bell a second blow when rebounding, raise the hammer spring by adjusting the nuts on the upright studs in the hammer stand until the hammer clears the bell on the rebound.

Should the clock stop at any time, and it is a striking clock, see if the detent arm on the fly arbor is caught on the releasing lever so the lift cam on the minute arbor cannot raise it; if so, and the strike weight is not run down, it indicates that the strike train failed to start positively when the releasing lever fell; and all parts pertaining to the strike mechanism should be inspected to see that the bearings are not gummed or dry.

If the strike train is clear when the clock is stopped, look for the obstruction in the time parts; if the gears between the minute arbor and the escapement are under tension and the connections to the dials are free, the trouble is in the movement. See that all bearings of the time parts are oiled and free--that no dirt or other obstructions have lodged in the teeth of the wheels or the leaves of the pinions, and that the escapement is in beat.

If the gears connecting to the escapement are free, and the connections to the dials are under tension, look for the trouble at the motion works or hands, and if these are found free, follow backwards toward the movement--testing each part in order until the trouble is located.


If, through any cause, the hands on the outer dials should not correspond with the hands on the small (setting) dial, or with the striking of the clock, stop the clock with the lift cam on the minute arbor in position to just allow the strike releasing lever to fall; then loosen the set screw which secures the couplings to the upright shaft on the movement, and turn the coupling forward or backward to bring the minute hand to the figure 12 (or XII), and the hour hand at the proper hour, and tighten the set screw again. With the hands all running alike, further change can be made if necessary by a setting device on the minute arbor which is turned with a key sent--each full turn of the key moving all hands--inside and outside, and also the the lift cam and snail wheel, one full minute.

The smaller size clocks, Nos. 4 and 14, not having this setting device, must be set by holding the escape wheel, loosening the set screw at the top of the pallets, sliding the pallets back and clear of the escape wheel, then letting the movement run until the desired time is indicated„always keeping control of the movement by pressure on the escape wheel arbor10, and being sure the escape wheel is stopped before sliding the pallets back in position. Let the movement run past the correct time sufficiently to allow ample time to get the pallets back in place, and the set screw firmly seated before starting the clock.

With the gravity escapement special care should be taken that the gravity arms are not bent while unpacking or handling them. The lifting pins at the center of the gravity escape wheel and the steel stops on the gravity arms should be oiled; but the rollers that bear against the pendulum rod should be kept clean and dry, as anything here that tends to make the rollers adhere to the pendulum rod when the arms are lifted by the escape wheel, will disturb the time-keeping qualities of the clock.

The clock may be set forward by swinging the gravity arms to each side to allow the escape wheel to run free.11

Oil all bearings on the movement with a synthetic oil about once in two months, or often enough to keep the oil limpid.12 Put a little oil on the pallets of the escapement weekly.  The journals, or bearings, should be oiled at the


outer end and at the inner shoulder, to be sure it will reach the full length of the bearings.  The motion works should also be oiled.13 The pulleys, hammer work and the cams14 on the strike wheel with a good machine oil about once a month.

To regulate the time, adjust the length of the pendulum by the knob at the top of the pendulum suspension, turning it to lengthen the rod to make the clock run slower, or turning it to shorten the rod to make the clock run faster. Before making this adjustment, loosen the knurled screws at the sides of the pendulum spring to slide between the bronze clamps, and afterward tighten the screws to hold the clamps firmly against the suspension spring. The ornamental nut at the bottom of the pendulum rod should first be adjusted so that the bottom of the nut is just even with a scratch mark on the brass piece at the bottom of the rod; then when the clock is regulated for time, the pendulum will swing clear of the safety hangars.

Final adjustment may be made by putting small weight (such as lead shot) in the cup at the top of the pendulum ball, to make the clock run faster, or removing them to make it run slower.


The electric release weight driven tower clock movement is constructed in the same general manner as the pendulum tower clock, but the time train is escaped once a minute or twice a minute by magnets which receive their impulse from a master clock. Cuts in the catalog show the escapement levers. Electric release tower clocks are usually installed in connection with secondary clock systems. They should be given the same care and attention as pendulum clocks. On these movements, however, there is no setting device; the usual method of setting the hands being to trip the magnet armature by hand or by rapid impulses from the master clock.


The synchronous motor tower clock consists of a motor having an absolutely constant speed, with a gear reduction to bring the motor velocity down to that of a clock.15 Some motors run at 3600 RPM, others at 1800 RPM, and others at much lower speeds. In every case, however, the motor speed depends upon absolute constancy in the current frequency, and can only be depended upon when the velocity of the power house prime mover is controlled by a master time piece. In the usual parlance this is spoken of as a


"regulated power supply."

As the motor of a synchronous clock must run continuously, any interruption of the current supply will stop the clock. When the current returns the motor will start again, but the clock will be slow16 Synchronous clocks are used for sign work and small advertising clocks, but have limited life and are not generally installed in public buildings or where access is difficult.


The automatic electric light switch is one of the attachments used most often. This consists of an arrangement for tripping on and off the electric lights which illuminate the dials. It is usually mounted on the top girt, geared into a bevel wheel on the upright shaft. Other locations for it are connected into the line of shafting, geared into the yoke shaft on the back of the movement; or mounted on a stand on the floor and drive by a downward shaft from the clock.

Independent electric light switches may be operated by a spring-wound clock movement or a synchronous motor. A slight difference in the time between the switch movement and the tower clock movement is of no importance in operating the lights.


On striking clocks and chiming clocks may be furnished devices for silencing the strike and chime to conform to a certain schedule, which may be changed at the will of the caretaker. A disk with 24 segments representing the hours of the day and night permit the silencing over a variable period simply by setting the segment outward. Care must be taken in installing the silencing device to see that the time of the segments corresponds with that of the pilot (setting) dial, and that the levers which hold up the rack and lockwork levers are free to function properly. Be sure that all segments are either all the way in or all the way out, otherwise the clock may get out of correct striking.


Hand silencing devices are for silencing the strike or chime manually when only required for short periods, such as during church services, etc. Blue prints of these are usually furnished to show method of installing.




1A "leaf" is a separate cast-iron square or round part of the weight. Back to text.

2 Mobil 1, SAE 5W30 or 10W30, is the current oil of choice. Back to text.

3 The cup is used to regulate the clock. Various small weights, such as lead shot may be added (to make the clock run faster) or removed (to slow the clock.) Back to text.

4 In a gravity escapement clock, the weight is used primarily to drive the external hands, and the wheels, up through the escape wheel. The impulse to the pendulum comes primarily from the arms which are lifted by the train, where in a conventional clock, the weight has a definite effect on the impulse to the pendulum. Back to text.

5 The reason for this is to prevent an attempt to drive the outside dial hands with too-great angles on the universal joints. A universal joint will jam and stop the clock if the angle is excessive. Back to text.

6  Modern usage accepts electrical conduit tubing, 3/4 to 1 inch external diameter. Back to text.

7 When using conduit for leading-off rods, it is recommended that new hubs be made up, or the old ones turned down to fit. Pinning the hub to the conduit is recommended over soldering. Back to text.

8 The "guard" is nothing more than a pin fitted across the groove of the pulley, placed there to keep the wire rope or chain from jumping out of the groove. Back to text.

9 Mastic cement is similar to the cement used to place ceramic tiles on a bathroom wall. The primary requirement is that it be waterproof, and capable of sealing the glass/metal joint against the weather. Back to text.

10 Needless to say, this can be a dangerous procedure. Do NOT let the clock run away from you--it may literally explode. Always keep one hand on the escape wheel arbor, and let the clock advance slowly. Keep the pallets away from the escape wheel--otherwise it will be damaged. Back to text.

11 Once more, this can be a dangerous procedure. Do NOT let the clock run away from you--it may literally explode. Always keep one hand on the escape wheel arbor, and let the clock advance slowly. Stop the escape wheel before releasing the arms. Do NOT just drop the arms to stop the clock--something will be damaged. Back to text.

12 Mobil 1 synthetic oil (SAE 5W30 or 10W30, according to climate) is the current oil of choice. A word of caution about oiling bushings: If any of the oil runs out of the bushing, ALL the oil will follow it.  Wipe up the overflow, and re-oil the bushing. Back to text.

13 It may be necessary to remove a section of glass or to open the inspection port in a wood or metal dial to oil the outer bearing in the hour pipe that carries the minute arbor. The south and west dials are particularly prone to needing frequent oiling. Back to text.

14 A light grease on the cams is preferred over oil. Back to text.

15 Keep your fingers out of and away from the gearing on these clocks. They cannot be stopped as can a weight driven clock. An emergency electrical shut-off should be placed within easy reach of the movement. Back to text.

16 It has been found that a voltage-sensing relay should be wired into the motor supply circuit. If power is lost, the relay drops out, and must be manually reset within the clock room. It has been noted that some of the synchronous motors will start up backwards as they age. Back to text.


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