Improvements in Lifts or Elevators.
Year: 1898

page_text: Date of Application, 12th Apr., 1898-Accepted, 2nd July, 1898
COMPLETE SPECIFICATION.
Improvements in Lifts or Elevators.
We, RUDOLPH CHARLES SMITH, of 214, Woodworth Avenue, in the City of
Yonkers, County of Westchester and State of New York, United States of
America, Engineer, and JAMES CRUICKSHANK, of 109, Albany Avenue, in the City
of Kingston, County of Ulster and State of New York, United States of America,
Salesman, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:-
The invention relates to improvements in elevators, and consists in a novel
safety appliance to mitigate or avoid the consequences resulting from a fall or run
away of an elevator car.
We present the invention in this application as embodied, for illustration, in an
elevator comprising the usual car and shaft, the latter being provided with sus-
pended slide-ways having a safety stop-clamp thereon, and the car being provided
with a projection or dog normally in the vertical plane of said stop but capable
of being removed therefrom at a definite point in the line of travel of the car,
in order that the dog may when desired pass said stop without touching the same.
The shaft is provided with a bar rail adapted to retain the dog in the vertical plane
of said stop and, at a definite point in the line of the travel of the car, to permit
the attendant to withdraw the end of the dog from the vertical plane of said stop in
order that said dog may pass free of the stop.
The slide-ways upon which the stop-clamps are placed are preferably of wood
and have an increased diameter below the normal position of the stops, and these
stops are preferably in the form of closed clamps encompassing transversely the
slide-ways and do not move on the latter except when the weight of the car is
brought upon them, at which time the said stop-clamps will by the weight of the
car and its contents be driven downward on the slide-ways and will scrape and
cut into the latter so as to arrest the car by a constant retarding resistance which
will produce a uniformly decreasing motion in the car until the latter comes to
a stand-still.
The invention will be more fully understood by reference to the accompanying
drawings, in which:-
Fig. 1 is a vertical section of an elevator shaft showing the car connected to a
hoisting gear, the car and shaft being provided with means constructed in
accordance with and embodying the invention. The shaft in this figure is broken
horizontally, and the figure illustrates the lower part of the shaft possessing the
DQ17

page_text: slide-ways and the upper part of the shaft at which the usual sheaves are placed
for the hoisting rope or cable.
Fig. 2 is a horizontal section through the car, shaft and connected parts,
looking downward upon the safety appliances constituting my invention; and
Fig. 3 is an enlarged side elevation of one of the dogs shown in its relation
to the stop-clamps and slide-ways; this figure also shows an enlarged top view of
a portion of one of the clamps or stops.
In the drawings the numeral 1 indicates a car and 2 the customary guide rails
secured to the guide posts 3. The car 1 is suspended by means of a suitable
hoisting rope or cable 4 which passes over the sheaves 5 to any suitable hoisting
apparatus 6. The car will be provided with any of the usual forms of control,
hand-rope, lever or electrical connections, for stopping, starting and controlling
the same.
The car is provided with a hand lever 7 which has its fulcrum at 8 in a stand 9
secured to the bottom of the car, and the lower end of the lever 7 passes through
the bottom of the car with sufficient clearance for operation. Under-
neath the floor of the car is pivotally mounted a three-armed lever, the arm 12 of
which is by means of the rod 10 connected with the lower end of the lever 7,
while the arms 13, 13 of said three-armed lever are by means of links connected
with the dogs 14, 14, which are adapted to slide in the enclosing casings 15, 15,
under the action of said three-armed lever. The casings 15 are secured to the
bottom of the car and support the dogs 14. The movement in one direction of
the three-armed lever will set the dogs 14 in their normal running position, which
is that illustrated in Fig. 3, and the movement of said three-armed lever in the
opposite direction will withdraw the dogs 14 inward so that they will pass clear of
the safety stops or clamps hereinafter referred to. The dogs 14 and the three-
armed lever with which they are connected may be directly operated by the
attendant in the car through the medium of the lever 7, and said dogs may also
be operated automatically when desired. Extending lengthwise of the elevator
shaft is the bar or rail 20, and the upper end of the lever 7 carries a pin or shaft 18
upon which is placed a roller 19 for engagement with said bar or rail 20, during
all of the travel of the car above the point at which the safety stop appliances
are intended to operate, and suitably adjacent to this point the bar or rail 20 is
provided with the outward curve 21 for the purpose of permitting the outward
movement of said lever 7 and the consequent inward movement of the dogs 14,
whereby the said dogs may be permitted to escape contact with the stops or
to be hereinafter referred to. The dogs 14, as above described, are normally in
or clamps
their outward position, shown in Fig. 3, and always remain in this position except
when the upper end of the lever 7 is moved into the outward curve 21 of the bar or
rail 20. The straight portion of the bar or rail 20 by its contact with the upper
end of the lever 7 imperatively maintains the dogs 14 in their outward position,
and the attendant in the elevator upon arriving at the outward curve 21 of said
bar or rail, must move the upper end of the lever 7 outward into said curve 21 if
he would prevent the dogs 14 from engaging the stop-clamps and arresting the car.
The dogs 14 have their outer ends hook-shaped to securely engage the stop-clamps
when meeting the latter upon the descent of the car, and the outer surfaces of the
ends of the dogs 14 are tapered downward and outward on a slanting line so that
said ends may not pass into operative engagement with the stop clamps during
the ascent of the car.
The slide-ways are preferably of wood and are indicated by the numeral 17,
in the present instance two slide-ways being provided at one side of the elevator
shaft and two slide-ways at the other side of said shaft. The slide-ways 17 are
secured at their upper part to the side of the elevator shaft, and hence said slide-
ways are in a suspended condition and have their lower portions free to afford a
retarding slide to the stop clamps 16 which are applied upon the upper portion of
said slide-ways. The stop-clamps 16 encompass the upper portions of the slide-
ways 17, where said slide-ways are of slightly less cross-section than below said

page_text: stop-clamps whereby a shoulder 30 on the slide-ways is formed and maintains the
stop clamps in a normally stationary position. In the present instance I have
formed each of the stop-clamps 16 to engage two of the slide-ways 17, and, as
indicated in the drawings, the dogs 14 protrude outward on a vertical line
extending between the slide-ways 17 in position to engage the central portions of
the stop clamps 16. The inner suface of the stop-clamps 16 are preferably serrated,
as indicated in Fig. 3, in order that they may engage and cut into the slide-v
-ways 17
in case of accident.
The accompanying drawings illustrate the slide ways 17 as suspended near the
lower portion of the elevator shaft, and it is my purpose to employ slide-ways 17
which shall be about one-fifth of the entire height of the elevator shaft, in order
that the stop clamps may be normally located at about one-fifth of the rise of the
car, since this arrangement and construction will give a safety sliding distance
for a gradual stop in case of an emergency.
During the ordinary travel of the car the safety dogs 14 are in their outward or
extended position, shown in Fig. 3, in order that in case of an accident resulting
in the fall of the car, the outer ends of said dogs may be in position to engage
said stop clamps 16. When during the usual employment of the car the latter
is approaching the outward curve 21 of the bar or rail 20 it will be the duty of the
attendant to push the upper end of the lever 7 outward into said curve in order
that the dogs 14 may be withdrawn inward and pass free of the stop clamps 16.
The outward curve 21 is of such pre-determined length that there will not be time
enough for the upper end of the lever 7 to enter the same whenever the speed of
the car exceeds a fixed limit; and thus, in case of a fall of the car, the upper end
of the lever 7 will not enter the outward curve 21 of the rail 20 and the dogs 14
will, , as a consequence, remain in their outward position and engage the stop
clamps 16. In the event of an accident and the fall of the car the dogs 14' will
engage the stop-clamps 16 and drive the latter downward upon the slide-ways 17,
the serrations of the stop-clamps abraiding or cutting into the slide-ways, whereby
the car will be stopped with a uniform and even resistance and not suddenly.
The slide-ways 17 are preferably of wood, since this material offers a uniform.
resistance, but they may be of other material and of any desired shape. When the
weight of the car is brought upon the stop-clamps, the latter move downward upon
the slide-ways 17 and thereby a uniformly decreasing motion of the elevator car
until the latter comes to a standstill is secured.
The form of the shoulder 30 on the slide-way 17 is not of material consequence
since whatever be the form of the slide-way 17 the object is that the stop clamps
shall by their abrading downward action and motion create a constant resistance.
In all cases the slide-ways 17 should be so proportioned that their surplus
material to be abraded by the stop-clamps shall enable the production of the
constant retarding resistance which will secure the uniformly decreasing motion
of the elevator car until the latter comes to a standstill.
The present invention is intended only as an emergency brake and may only
come into play a few times during the entire life of the elevator apparatus.
The operation of the elevator illustrated is the same as usual except that the
attendant when passing the curve 21 in the rail 20 will press the upper end of the
lever 7 into said curve and thereby prevent the dogs 14 from engaging the stop-
clamps 16.
It is evident that the movable dogs 14 and curve 21 will be dispensed with
whenever the car in its ordinary course does not pass below the stop clamps 16,
but always stops, except in case of accident, before the car could strike the stop
clamps. In this latter arrangement a permanent projecting arm or other rigid
structure of the frame of the car placed to contact with the stop clamps 16 in case of
accident would take the place of the special dog 14 shown. In other words, under
the conditions just cited, the car would employ a fixed dog 14 to engage the stop-
.J

page_text: clamp instead of a movable dog 14, since the movable feature of the dog 14 is only
useful when the car in its usual course of travel is obliged to pass by the stop
clamps 16.
A great advantage derived from suspending the slide ways 17 from a point of
the elevator well or shaft and leaving them free on all sides to be acted upon by
the clamps, as well on the face as on the back, is that this arrangement keeps
the slide-ways in line for direct tension and takes up the least space between the
car and elevator shaft. The slide-ways 17 may be easily re-placed by new ones
whenever in case of an accident a sufficient length of their surface has been abraded
by the stop-clamps 16.
It is one of the purposes of the present invention, as above explained, to secure
a constant retarding resistance which will produce a uniformly decreasing motion
of the elevator car until the latter comes to a standstill; and we have found that
an abrading cut of one inch in width and from one-eighth to one-quarter of an
inch in depth in yellow pine slide-ways offers a constant resistance against abrasion
of about one thousand pounds. With this example of resistance given it is an
easy matter to calculate the total aggregate width of the abrading cut of all of the
slide-ways for a given height of fall.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:-
1. The combination with an elevator car having part of its structure projecting
in the way of normally stationary clamps, of an elevator shaft in which said car
moves, slide-ways supported in tension by said elevator shaft, and the normally
stationary clamps on said slide-ways to be engaged by said projecting part of the
car structure, the portion of the slide-ways below said clamps being proportioned
to resist the motion of the clamps and the latter being slidable by abrading the
slide-ways, as described.
2. The combination of an elevator car having movable dogs normally in the
path of safety clamps, of an elevator shaft in which said car moves, slide-ways
supported in tension by said elevator shaft, clamps normally stationary on said
slide-ways and in the path of the movable dogs but slidable by abrasion on said
slide-ways, and means to keep the dogs from striking the stop clamps when the
car travels at a safe speed, as described.
3. The combination of an elevator car having movable dogs normally in the path
of the safety clamps, with an elevator shaft in which said car moves, slide-ways
supported in tension by said elevator shaft, stop clamps normally stationary on
said slide-ways, and in the path of the movable dogs, but slidable by abrasion on
said slide-ways, means for keeping the dogs from striking said clamps when the
car travels at a safe speed, and a compulsory track for maintaining said dogs in a
normally outward position, as described.
4. The elevator car, the movable dogs carried thereby, and mechanism for
operating said dogs, combined with suspended slide-ways located in the elevator
shaft and arranged in pairs, and the stop-clamps encompassing said slide-ways
and normally stationary thereon, the inner surfaces of said clamps being serrated
and said slide-ways below the normal stationary position for said clamps being
of greater cross-section than at said clamps; substantially as set forth.
5. The elevator car, the movable dogs carried thereby, the lever mechanism for
operating said dogs, and the stationary rail for said lever mechanism, the said rail
having the outward curve at a definite point, combined with the suspended slide-
ways in the elevator shaft, and stop clamps on said slide-ways and in the path of
said dogs when the latter are in their normal outward position, said slide-ways
having a greater cross-section below than at said stop clamps; substantially as
set forth.
6. The car having a projecting arm, combined with a vertical slide-way sus-

page_text: pended in the elevator shaft, and a stop clamp on said slide-way and normally
stationary thereon and in the path of said projecting arm; substantially as set
forth.
Dated this 29th day of March 1898
RUDOLPH CHARLES SMITH.
JAMES CRUICKSHANK.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.