(the following text is from the original sales brochure)


John W. Mabbs It is only a question of time when steam and hydraulic elevators will be a thing of the past, for the reason that it is desirable to have but one kind of power in a building, and that ELECTRICITY. All that is necessary for the passing of the other types of elevators, is to produce an electric elevator as safe, as speedy, as reliable, as efficient, and as economical as the best type of hydraulic elevator. This has at last been accomplished by the following described elevator: The cut on the opposite page (Fig. 1) shows the general arrangement of the machine, car, cables, buffers, etc.

The principle of this elevator is that the machine constitutes the counter balance of the car and its average load, and is the only counter-weight. The cables are arranged so that the machine is geared two to one; for every foot the machine travels, the car travels two feet, and as the machine ascends the car descends, and vice versa. By this arrangement, the machine shaft only extends about one-half the height of the building.

Figures 2 and 3 give an idea of the construction and design of the machine. The machine has a vertical armature shaft, upon which are mounted in order the brake pulley, upper bearing, commutator, armature, coupling, worm, lower bearing, and roller thrust. The armature is. keyed rigidly to the shaft and is connected to the worm, which is really a sleeve on the shaft, by means of the coupling shown. The idea of this arrangement is that the coupling may be disconnected, permitting the rotation of the armature, for the purpose of smoothing up the commutator, etc., without operating the gearing. The worm drives the two worm wheels, which are mounted on the two horizontal shafts, and on these shafts are four pinions which engage the four vertical racks, and these, in turn, are mounted on two cast iron columns, that form the structure up and down which the machine operates.

The current is conducted to the motor by means of two trolley rails, which consist of small steel channels lined with a flat copper bar and are mounted upon porcelain insulators. the current is taken from the trolleys by means of specially designed brushes of utmost simplicity and durability.

All the working parts are practically submerged in a vat of oil, and are automatically and perfectly lubricated for an indefinite period of time without attention or renewal. All the machines so far installed have tun two and a half years or more without changing or renewing the oil. The only two points on this machine that require oiling are the idler and the upper bearing. These are provided with compression grease cups and require little attention.

Due to the principle of this elevator, the large sheave wheels used, and the single bend the cables make per trip, the life of the cables is unusually long, being several times as long as on other makes of elevators. This is proven by the life of the cables on the first machine installed, which are still in good condition after seven years of service, and after making nearly 35,000 car miles.

Figure 4 shows the detail of the lower oil buffer, and the upper buffers are clearly shown in Figs. 1 and 2. These buffers are designed with sufficient capacity to take care of the momentum of the machine when traveling at full speed, plus the power of the motor, and form an absolute mechanical stop.

The motor of this machine is of special design and is what is known as the Warner wound type, which is particularly adapted for elevator work.

This elevator is controlled by a hand switch in the car, from which the operator can obtain anyone of three speeds. This gives a large range of speed to the car. The controller is of the full magnet type, built by J. L. Schureman & Co. A bank of four of these controllers, in the form of a hollow square, is shown on page 6 (Fig.5), and a more recent installation is shown on page 8 (Fig.6).

The operation and control of this elevator is pronounced BY ALL to be "IDEAL," its start and stop being very quick and at the same time very smooth, it being possible to reverse this car when going at full speed without a perceptible pause, and without the slightest shock or jar. It eliminates all of the disagreeable sensations so pronounced in other types of elevators. These features mean increased and satisfactory elevator service, and make it particularly adapted for service where ladies are patrons.

The speed of this elevator is practically unlimited and can be increased to any desired amount. At the Chicago Board of Trade Building, the local cars are making 540 feet per minute and the express car as high as 600 feet per minute. A much greater speed can be given and safely controlled, if desired, especially for extremely high buildings. What this means can be better appreciated when considering the statement made by elevator experts (see page 17), that 400 feet per minute is the limit of other types of electric elevators.

Due to the principle of this machine, the force of gravity is utilized to its greatest possible extent. Friction is reduced to a minimum, and the power of the machine is not consumed in a lot of multiplying sheaves and intermediate devices, but is applied almost directly to the work to be performed. This is more clearly shown by the actual results obtained from this elevator in regular business, and business that has been pronounced by very prominent electrical elevator men to be the severest in the country. The service of the machine shown on page 10, when doing regular express duty, stopping at five out of nine floors, on a test, made 547 round trips in 540 minutes. The average current consumption for this same car running at a speed of 575 to 600 feet per minute, was 3.44 K.W. per car mile for a period of several years, there being days when the conditions were such that the current dropped below 3 K. W. per car mile. The results obtained from the four machines shown on pages 12 and 14 is given in the report on page 19, but they have since shown an average of 3.083 K. W. per car mile for a considerable period of time. These cars are larger and run "local."

This machine consists of very few parts, all of which are made with a superabundance of strength and wearing surfaces, thereby insuring long life and durability, and preventing the danger of break downs, which are always annoying, and often extremely dangerous. The machine is made as nearly "Fool Proof" as is possible to human ingenuity. This is only possible in a simple and well constructed machine, built upon these principles, and is impossible in a complicated machine of any description. The mechanical detail of this machine is practically perfect; no chances are taken; every precaution is used to prevent anything breaking, getting loose, or out of place. How well this has been accomplished is shown by the first machine built (page 10, Fig.7), which ran over three years without missing a day, and has only missed two days for repairs in almost seven years, and this was due to armature trouble. At the same time the machine is made so that all parts are easily accessible and quickly taken apart and repaired. After durability, the first consideration is to be able to make repairs quickly and cheaply. Due to the foregoing facts, this machine requires but little attention of any description, and the maintenance and repairs are practically nothing in comparison with other elevators, as shown by the repairs of every description on the first elevator, including signals, car, cables, inclosures, and city inspection, which amounted to $542.58 for nearly seven years,-or an average of $77.51 per year. The elevators which have since been installed, come very close to this average of maintenance, as shown by the report on page 19. These figures talk for themselves and are almost incomprehensible to other elevator men.

This elevator is particularly adapted for high buildings, there being practiically no limit to the height this elevator can be run. Increasing the travel of the car to 600 feet, or even more, adds no complications to this machine, or changes any of its conditions, or in any way reduces th6 safety or efficiency of the elevator. It is the only elevator in existence, of any description, of which this can be said. This elevator will solve the most difficult problem now disturbing the promotors of extremely high buildings. For buildings that are put up with the intention of increasing their height in the future, there is no elevator so well adapted for this purpose, for the reason that the height of the elevator structure can be increased at the same time as that of the building, without in any way interfering with the elevator service, and at comparatively trifling cost.

The time is fast approaching when more than one car will operate in the same elevator shaft, in high buildings. The Mabbs elevator is particularly adapted for this purpose, for the reason that the machines that operate the cars in one elevator shaft can be placed in the same machine shaft, and work up and down the same structure, and can be arranged so they will come together before the cars in. the elevator shaft: .By placing suitable buffers between the machines to cushion their impact in case of failure of the automatics, it would make the multiple elevator scheme both feasible and safe.

This elevator is protected by a basic patent, which has been examined by some of the ablest patent attorneys in the country, and they state that "it does not infringe in any shape or form any of the sixteen hundred and forty odd patents that are now in force in the patent office on elevators and lifts."

The great feature of this machine is its safety, which should be the first consideration in any elevator. Automatic stops are placed at both ends of travel of the machine, which slow down the machine, cut off the current and set the brake, in case the operator fails to do so, and if the machine goes beyond this point, it trips the main circuit breaker, or over-load switch, and cuts the current off of both the controller and the machine. Beyond this again are the buffers, or mechanical stops, which are sufficient to safely take care of the machine in case the operator and all automatics fail. It is evident from these arrangements that the car can never be jerked into the overhead work and the cables pulled out of the car, as has often happened in other types of elevators; neither can the car be dropped into the basement and the counter-weights pulled down upon the car, the most common and serious accident in other elevators. (See what the insurance inspectors say upon this subject, page 16). A greater strain can never be put upon the cables of this elevator, than the load in the car. A push button is placed in the car whereby the main circuit-breaker can be instantly tripped by the operator, shutting off the current from both controller and machine. This is for use in case of disarrangement of the car box or the controller. Finally, when the same number of cables are used on this as on other machines, it gives it one-third greater factor of safety, for the reason that the cables that usually go to the counter-weights, in this case go to the machine, there being no counter-weights except the machine itself. Again, the cables of this elevator will last from four to ten times as long as on other elevators, due to the fewer bends, and less wear, thereby diminishing in the same proportion, the danger of broken cables.

With its average expenditure for maintenance, past service shows this elevator will last a lifetime.

Copy of a letter sent to one of the leading Casualty Insurance Companies by one of its ablest Inspectors:

Quotations from the report of Pierce Richardson & Neiler, Engineers, Chicago, on electrical elevators, to the Real Estate Committee of the Board of Trade, dated Dec. 31st, 1904. .

In deciding between hydraulic and electric elevators, they say:
..."We are forced to the conclusion that the best thing to do all things considered will be to install new electric elevators which will operate on a less energy consumption than the "Sprague".
..."The 'Mabbs' machine runs at a much higher speed than any other electric elevator, even the latest type of the 'Otis', this being what is known as their friction machine".
..."The ordinary speed of a common drum machine does not exceed 350' per minute."
"The 'Mabbs' elevator runs at a speed of from 575' to 600' per minute."
"The performance of the Mabbs Elevator is excellent and better than can be realized with any existing drum machines".
"All drum machines are incapable of being run at a speed greater than 400 feet per minute."
"It is evident that any machine which is capable of running at a greater final speed than 400 feet per minute will give better service provided of course the elevator is still smooth running and does not shock nor jar passengers upon starting or stopping. These conditions are preserved in the 'Mabbs' machine."
"As to the economy or maintenance, we believe that the 'Mabbs' elevator as at present installed in the building will not be as expensive to maintain as even the best drum elevator."
"The 'Mabbs' "in its present condition is operating satisfactorily and at minimum cost for repairs."
"The kilowatt hours consumption is relatively small."
"The car is at all times under perfect control of the operator".
"The 'Mabbs' machine shows an economy over existing machines."

Efficiency Test of Mabbs Electric Elevators at the Chicago Board of Trade (9.45 Mb, PDF)

Copyright © 2004 M.L.Mabbs