US2031043A

US2031043A - Elevator safety device

Info

Publication number: US2031043A
Application number: US26720A
Authority: US
Inventors: Hymans Frederick
Original assignee: Otis Elevator Co
Current assignee: Otis Elevator Co
Priority date: 1935-06-15
Filing date: 1935-06-15
Publication date: 1936-02-18
Anticipated expiration: 1953-02-18

Description

Fgh. 18, 1936. F. HYMANS 2,031,043

ELEVATOR SAFETY DEVICE Filed June 15, 1935 3 Sheets-Sheet l ATTORNEY V INVENTOR Feb. 18, 1936. HYMANS ZQGBEJM'E ELEVATOR SAFETY DEVICE Filed June 15, 1935 3 Sheets-Sheet 2 Patented Feb. 18, 1936 TATES PATENT OFFIE ELEVATOR SAFETY DEVICE Application June 15, 1935, Serial No. 26,720

20 Claims.

The invention relates to safety devices for elevators and especially to that type of safety device or brake in which the elevator car or counterweight, during its downward movement, is brought to an emergency stop by applying means to the guide rails to exert a braking action. a

In the normal operation of elevator installations, the rail engaging means are kept out of engagement with the rails. Means are provided for causing the rail engaging means to be applied to the rails for bringing the movable body (say the elevator car) to a stop in the event of 'overspeed, and for this purpose a centrifugal governor may be employed. It is important that the rail engaging means be applied to the rails with a force sufficient to insure bringing the downwardly moving body (car or counterweight) to a stop and yet without damage to apparatus or 20 injury or discomfort to occupants of the car. It

is also important that the rail engaging means be released from the rails only when it is safe to do so and it is desirable that such release may be readily effected.

The principal object of the invention is to provide a safety device having such characteristics.

One feature of the invention is the provision of a safety device in which the maximum force with which the rail engaging means engage the guide rails is predetermined and may be readily adjusted.

Another feature of the invention is the utilization'of the weight of the downwardly moving body in applying the rail engaging means to the guide rails.

Still another feature of the invention is the provision of a safety device which can be released only by upward movement of the movable body for which it is provided.

Another feature is a safety device in which the engaging of both guide rails by rail engaging means is assured.

A'further feature resides in a safety device in which the nail engaging means are maintained in engagement with the guide rails when the device is operated.

Another feature is the provision of a safety device which is of simple construction, reliable in operation and which may be safely operated a considerable number of times Without any replacements.

Other features and advantages will become apparent from the following description and appended claims.

In the drawings:

Figure 1 is a schematic representation of an elevator system illustrating the adaptation of a safety device embodying the invention to an elevator car;

Figure 2 is a diagrammatic representation for illustrating the principles of operation of the invention; 7

Figure'3 is an enlarged fragmental detail taken along the line 33 of Figure 4 of one of the rail clamps employed as a part of the safety device shown in Figure 1;

Figure 4 is a view inside elevation, with parts broken away, illustrating details of the safety device shown in Figure 1;

Figure 5 is a top view of the mechanism shown in Figure 4;

Figure 6 is an end view of the mechanism shown in Figure 4;

Figure '7 is a fragmental view of 1a modified arrangemenit of the details of the safety device shown in Figure 1; and.

Figure 8 is a side elevation similar to Figure 4, but with certain parts of the mechanism modified.

Reference will first be had to Figure 2, in which mechanism is diagrammatically shown for illustrating the principles of operation of the invention. A cross member 55, hereinafter termed the safety plank, is suspended beneath the elevator car l0. Shoes 9 are illustrated as the means for engaging guide rails l6. Means for moving the shoes into'engagement with the guide rail are provided at each end of the safety plank. This means is shown in the form of a pair of levers pivotedat the ends of the plank. Springs extend between the levers I and the elevator car. The safety plank is suspended in such way as to be free to move upwardly with respect'to the elevator car. Stops 6 on the car and the safety plank limit the amount of such upward movement. The arrangement is such that so long. as the safety plank is not moved upwardly with respect to the elevator car, shoes 9 are disengaged from the guide rails. A rope 5| is illustrated as a means for lifting'the safety plank. This rope is shown as passing around

sheaves

89 and 99 secured to the elevator car.

Assume that the elevator car is moving downwardly. Upon a pull being exerted on rope 5| the safety plank is lifted, decreasing the distance between the safety plank and the car. This swings levers I about their pivots in a direction to move shoes 9 into engagement with the guide rails. Th s re ards the safety nk in its w ward movement, further decreasing the distance between the safety plank and the elevator car. As the safety plank is retarded, the elevator car, due to its downward movement, acts through springs 85 to exert a force tending to keep the safety plank in motion. As this force is transmitted to the safety plank through levers 1, the force applying shoes 9 to the guide rails is increased as the compression of and therefore the pressure exerted by springs 85 increases. The compression of the springs and thus the force applying the shoes to the rails increases as the distance between the safety plank and the elevator car decreases until upward movement of the plank with respect to the car is terminated by the engagement of stops 6. Thereafter, the car and safety plank are retarded as a unit with a force which is determined by the amount of compression of springs 85 until the car and plank are brought to a stop.

The safety device is released by upward movement of the elevator car. As this upward movement takes place, springs '85 expand, decreasing the force with which shoes 9 engage the guide rails until this force is no longer suificient to maintain the shoes in engagement with the guide rails, whereupon they are released.

Before describing details of a specific-embodiment of the invention, reference will be had to Figure 1 for a general understanding of an elevator system to which the safety device may be applied. Hoisting ropes l2, for the elevator car I0 and counterweight ll, pass over a hoisting drum 13. This drum is rotated by hoisting motor l4. An electromagnetic brake I5 is illustrated for bringing the motor and consequently the car and counterweight to a stop. Only the guide rails l6 for the elevator car are shown, but it is to be understood that guide rails are also provided for the counterweight. The car is provided with upper guide shoes l8 and lower guide shoes 20 for cooperating with guide rails 16 to guide the car in' its movement in the hatchway;

A governor rope 2| extends around governor sheave 22 at the top and tensioning sheave 23 at the bottom of the hatchway, the tensioning sheave 23 being provided with weights 24.. Governor sheave 22 is mounted upon a'governor shaft 25. Shaft 25 geared to governor .spindle26. The governor is illustrated asof the fiy-zball type, being provided with centrifugal weights 21, weight arms 28, sleeve 30, connecting links 3|, and resisting spring 32. Two'eccentric'clutches 33 and 34 are rotatably mounted-upon shafts 35 and 36 and caused to move togetherby spur gear segments 31 and 38. Shaft 35 ismounted upon a movable rod 40, the rod being mounted in a frame 4|. A spring 42, abutting against a portion of the frame and a collar 44 on the rod, forces clutches 33 and 34 together and consequently acts upon rope 21 as it passes through the clutches when the clutches are thrown to engage the rope. Thus governor rope'2fis allowed to slide through clutches '33 and 34 but at the same time exerts a pull suflicient' to apply the safety. A spring pressed latch 45 engages a projecting portion of 'clutch 34 to prevent application of the clutches until the governor acting through

links

46 and 41 effects a. release of the latch.

The governor rope is connected to the elevator car by means of a hitch 48 which is normally held in a releasing carrier .50 attached to the elevator car. Rope 5| secured to the hitch connects the governor rope to thesafety brake; When the governor acts to grip the governor rope, hitch 48 is withdrawn from releasing carrier 56 and as the elevator car descends tension is exerted on rope 5| to apply the safety brake to guide rails 16 as will be hereinafter set forth.

Referring now to Figures 3 to 6 inclusive, according to the preferred construction, the safety brake comprises two rail clamps 54, one for each guide rail. These rail clamps are pivotally supported by safety plank 55 at opposite ends thereof, the safety plank in turn being supported by the elevator car for relative movement with respect thereto in a manner to be described later. The safety plank comprises a housing 56 for each rail clamp, joined by channel members 51. The rail clamps are identical in structure and only one of them will be described in detail.

Each rail clamp comprises two jaw members 58 pivotally mounted on pins 60, see particularly Figure 3. These pins are mounted in housing 56, being supported thereby at the top as by shoulders 6| (see Figure 4) formed on the pins and held in place at the bottom as by cotter pins 62. Each jaw member is formed on its outer end with a vertical semi-cylindrical recess 63. Within this recess is fitted a rail gripping memher or shoe 64. This shoe has a semi-cylindrical bearing surface to fit within recess 63. The shoe is held against the jaw by a screw 65 and spring 66, the aperture 61 in the jaw through which the screw extends being enlarged so as to permit the shoe to swivel with respect to the jaw. The face of each shoe 64 is made of a size, as by slotting the shoe vertically as illustrated, to provide an optimum of pressure per unit area when the safety brake is applied. In other words, the bearing surfaces of the shoes are made as small as is permissible by the amount of wear which would result on the shoes and guide rail. This arrangement acts, when the shoes are applied, to squeeze out any oil which may be present on the guide rail from beneath the clamping surfaces of the shoes.

The jaws are biased about their pivot pins into positions in which the shoes normally disengage the guide rail. For this purpose, a tension spring 10 extending between the jaws at the inner ends thereof may be utilized. The jaws are moved into position to engage the rail against the force of the biasing spring by wedge 1|. Rollers 12 are rotatably mounted on pins 13 at the inner end of each jaw between which the wedge moves in a direction toward the center line of the car to apply the jaws. The biasing spring 10 is hooked in slots 14 provided at the upper ends of these pins.

The wedge 11 is pivotally connected to a bell crank lever 15 as by pin 16, the outer end of the wedge being bifurcated to receive arm 11 of the bell crank. The wedge is provided with a top plate 18 and a bottom plate 86 which act to retain the wedge in position for cooperating with the rollers and to guide the wedge between the rollers when it acts to spread the jaws to apply the shoes to the rail. The bell crank is pivotally supported by the rail clamp housing, the pivot pin 81 for the bell crank extending between spaced lugs 62 depending from the housing,

The other arm 83 of the bell crank lever is pivotally secured to the bottom spring seat 84 for compression spring 85,-the pivot pin 86 for arm 83 extending between lugs 81 formed on the spring seat. Spring 85 extends between lower spring seat 84 and an upper spring seat 90. The spring is held in compression by means of rods 9| extending between the spring seats. Nuts 88 on the lower ends of the rods serve to adjust the compression of the spring and to lockit in adjusted position. The upper spring seat is secured to the lower cross beam 92 of the elevator car framework as by bolts 93, spacers 94 being provided between the crossbeam and the seat.

Crossbeam 92 comprises a pair of channels secured at their ends to opposite sides of vertically extending channels 96, which form the side members of the car framework. Reinforcing plates I9 are provided at the ends of the crossbeam between channels 95 and each of side channels 96. A bracket 91 is provided at each end of crossbeam 92. Each bracket extends across the beam between the channels 95 and is secured to the lower flanges of the channels as by bolts 98. Each of these brackets carries one of the lower guide shoes 20 for the elevator car.

The safety plank is suspended beneath crossbeam 92 by means of rods I00, one at each end of the crossbeam. The upper end of each rod is of reduced diameter. This reduced portion extends upwardly through an aperture formed in the portion of bracket 91 extending between channels 95.

The upper end of the rod is threaded to receive a nut IOI which acts to clamp the shoulder formed on the rod by the reduced portion against the bracket, thereby securing the rod to the crossbeam. Each rod extends downwardly through recesses I99 formed in the top and bottom of the rail clamp housing at the corresponding end of the safety plank. V Beneath this housing the rod is formed with a shoulder I02 and the lower end of each rod is threaded to receive a nut I03. This lower threaded end extends through an aperture in a supporting plate I 04 which is secured against shoulder I02 by nut I03. This plate extends crosswise of the safety plank and. has at its ends adjustable abutment screws I05 upon Which rest the rail clamp housing at'that end of the safety plank. In this way, the safety plank is suspended from the framework of the elevator car and is free to move upwardly with respect thereto.

The application of the safety brake shoes to the guide rails is effected by upward movement of the safety plank with respect to the lower crossbeam of the elevator car framework. This is due to the fact that as the safety plank lifts off its supporting screws I05, the pivot point 8| of each bell crank lever I5 is moved upwardly with the plank. Pivot pin 86 forms the fulcrum for the bell crank during this movement, owing to the fact that this pin remains stationary until a force is exerted sufiicient to overcome the force of spring 85. Thus, each bell crank is swung in the direction about its pivot point 8! to force its wedge H between rollers I2. Referring to the right hand bell crank of Figure 4, for example, this bell crank is swung counter-clockwise about itspivot pin 8| as the safety plank moves upwardly relatively to the crossbeam 92, thereby forcing the wedge between the rollers of the .rail clamp jaws. This forces the inner ends of the jaws apart, swinging them about their pivot pins to apply the shoes to the guide rail.

Upward movement of the safety plank with respect to the crossbeam 92 to apply the safety brake is effected by means of rope 5I connected to the hitch 48 on the governor rope. passes around a sheave 99 carried by the elevator car and is connected to the safety plank through a system of levers. The end of rope 5| is secured to a thimble I06, the outer end, of which is bifurcated to receive a lever IN. The

hand rail clamp work is permitted. Anabutment block Rope 5I thimble is pivotally connected to lever I 0'! by means of a pin which extends between the bifurcations of the thimble. Lever I0! is secured to the outer end of a shaft I 08 as by a key II 0 and set screw II I. A similar'lever I I 2 is secured to the outer end of ashaft I I3 in a similar manner by a key and set screw. The shafts I08 and H3 extend crosswise of crossbeam 92 of the elevator car framework, being supported in apere tures formed in channels 95. The ends of these levers are connected as by a turn buckle II4 so as to adjust them into exact parallelism. Nuts II5 are provided to lock the levers in adjusted position. A lever arm H6 is secured as by a key and set screw to shaft II3 midway between the channels 95. This lever arm is connected by links III to the right hand half (as viewed in Figure 4) of the safety plank. The lower ends of the links are pivotally secured to a lug I20 formed on the rail clamp housing for the right as by a pin I2I. In a similar manner, a lever arm I22 is secured to shaft I08 midway between channels 95. Lever arm I22 is connected by links'I23 to the left hand half (as viewed in Figure 4) of the safety plank. The lower ends of links I23 are pivotally secured to a lug I24 formed on the rail clamp housing of the left hand rail clamp as by a pin I25. Upon a pull being exertedon rope 5|, levers I 01 and I I2 are swung counterclockwise as viewed in Figure 4. This causes counterclockwise movement of lever arms I I6 and I22, which act through the links to lift the safety plank.

Only a limited amount of upward movement of the safety plank with respect to the car frame- I28 is provided on the top of the safety plank at each end thereof. Each of these blocks may be of wood, as indicated, secured in an elongated recess I30 formed on top of the rail clamp housing at the corresponding end of the safety plank. An abutment plate I3I is provided for each block. These abutment plates are secured as by screws I32 to the bottom of brackets 91 in the paths of movement of the abutment blocks. Shims I33 are provided between the abutment plates and the brackets for purposes of adjustment. An abutment I34 depends from the car framework for engaging the buffer I35 at the lower limit of travel.

In operation, elevator car I0 is caused to move up and down in the hatchway by motor I4, the car transmitting motion to the governor by means of rope 2|. So long as the elevator 'car runs at a speed less than the predetermined speed for which the governor is set'to cause operation of

clutches

33 and 34, no relative motion takes place between car I0 and rope 2| since the releasing carrier 50 exerts suificient force'to hold hitch 48 in place against the inertia of the governor in starting and stopping. In the event that the speed of car I0 in its downward motion exceeds this predetermined speed, the governor operates to release latch 45, allowing clutches 39 and 34 to fall by gravity and grip rope 2| with a force depending upon the strength of spring 42. This gripping action retards movement of rope 2I to release the hitch 48. The retardation of the governor rope pulls rope 5| to swing levers I0? and H2 in a direction to lift the safety plank off its abutment screws I05. As this movement takes place, bell crank levers I5 are swung about their pivots BI as previously described, to force wedges II between the rollers of their respective jaws. The inner ends of the jaws are thus forced apart,

applying shoes 54 to the guide rails. This retards the downward movement of the safety plank. As a result, the clearance between the safety plank and the car framework is further decreased. This increases the force with which the jaws clamp the rails. The force initially applying the shoes to the rails is due to the retardation of the governor rope. Thereafter this force is augmented by the weight of the car, for as soon as the plank is retarded the car, acting through springs 85 and bell cranks I5, exerts a .force tending to keep the plank in motion. The

car, continuing its downward movement, acts through springs 85 and the springs in turn through bell cranks I5 to increase theforce applying the shoes to the rails as the clearance between the safety plank and car framework is taken up. The spring seats 84 remain in contact with nuts 88 until the force acting against the springs due to the brake application becomes equal to the initial compression of the springs. Thereafter the springs are further compressed as the retarding force increases, spring seats 84 sliding upwardly on rods 9I as this further compression of the springs takes place. This action continues, increasing the force of application of the rail clamps to the guide rails until abutment plates I3! are engaged by abutment blocks I28. When this occurs, no further relative movement between the safety plank and the car framework takes place and these two parts move as a unit until theyare brought to a stop by the action of the rail clamps. The amountof. retarding force exerted by the rail clamps after the gap between abutment plates I3I and abutment blocks I28 is closed is determined by the force exerted by springs 85 in their compressed condition, the compression being preadjusted, as by shimming abutment plates I3I, to meet the requirements of the particular installation.

The. above action from the time the shoes 64 engage the guide rails until the gap between the abutment plates and abutment block is completely taken up occurs very rapidly, effecting a quick braking of the car. Furthermore, owing to the fact that the simultaneous lifting of both ends of the safety plank is assured by the parallel arrangements of levers I81 and I I2, the application of both rail clamps to the guide rails is also assured.

In order to reset the safety brake, the car is moved upwardly. It is preferred first to reset the

governor clutches

33 and 34, releasing the governor rope. As the upward movement of the car takes place, the safety plank remains stationary so that springs 85 expand. As soon as lower spring seats 84 engage nuts '88, the force holding the wedges between the jaws ceases. The safety plank therefore immediately drops onto its abutment screws I85. Bell crank levers are swung back about their pivots 86 as the safety plank drops, moving the wedges 'II from between the rollers l2. As the wedges are withdrawn, springs I8 move the jaws back about their pivots into positions where the shoes disengage the guide rails.

The safety brake can be released without resetting the governor clutches if desired. .If done in this manner, the governor rope will be pulled between the clutches as the safety brake is released, due to the fact that the levers I01 and I I2 take up on rope 5I as the car moves upwardly faster than the upward movement of the car takes place. Release of the safety brake without resetting the governor jaws may be desirable in order thatpassengers may be taken immediately to the next floor and discharged from the car. The governor and releasing carrier, however, must be reset before normal operation of the car is resumed.

In Figure 7 an arrangement is shown for adjusting for equal clearances between the brake shoes andthe guide rail. This arrangement is shown for. only one end of the safety plank, the construction for the other end being the same. It comprises a plate I48 having a slot I4I which forms a guide for rod I00. The guide plate is securedto the rail clamp housing by screws I42 which extend through slots I43 in the plate. The position of the plate with respect to the housing is adjustable by means of screws I44 which extend through ribs I45 on the housing. Thus by this arrangement, the clearance between each shoe 64 and the guide rail can be made the same and the guide plate then looked in adjusted position. By proper manufacture and with recesses I89 in the housings of a width only slightly greater than the diameter of the rods, equal clearances between the shoes and rails may be obtained without the adjusting arrangement of Figure '7.

In Figure 8 an arrangement is shown in which mechanism is provided which equalizes the force exerted by springs 85 and thereby equalizes the force with which'the shoes of the rail clamps are forced, against the rail by the springs when the safety is applied. This arrangement comprises a pair of oppositely mounted bell crank levers I50 and I5I, pivotally mounted at I52 and I53 on crossbeam 92. The upwardly extending arms I54 of the bell cranks are joined by a link I55 and the other arms I 56 arerespectively connected to upper spring seats I58 for springs 85, lugs I5'I being formed on these seats through which pivot pins I58 extend to join the bell cranks to the springs. With this arrangement, should either spring tend to exert a force greater than the other, this difference in force is transmitted through the bell cranks and link to the other spring. This arrangement insures the simultaneous application of the rail clamps to the guide rails, for should the shoes of either clamp touch their rail ahead of those for the other clamp, any force tending to cause them to grip the rail is transmitted through the equalizer arrangement to cause the shoes of the other clamp to move into engagement with their rail. Thus, whereas in the arrangement of Figure 3 to 6, the engagement of both rail clamps with the rails is insured, the equalizer arrangement of Figure 8 causes their simultaneous application.

The safety plank being supported by the elevator car and the safety brake being connected to the governor rope, unwarranted operation of the safety brake is prevented. Also, the connection of the bell cranks to the car through springs 85 permits the kinetic energy of the car to be utilized to provide force for applying the shoes to the guide rails, once they have been moved into engagement therewith by retardation of the governor rope. Thus a large force is available for applying the brake.

The ultimate brake applying force is dependent upon the force exerted by springs 85 when the clearance between the plank and the car framework is taken up. This is adjusted so as to provide brake applying force sufficient to bring the car to a gradual stop without shock tothe occupants of the car. With this arrangement, the springs also yield when the rail clamps ride over thick spots inthe rail, thereby preventing the transmission of shocks to the elevator car due to unevenness of the guide rails.

The construction of the rail clamps permits the shoes to extend well over the sides of the rails, with sufiicient allowance for any spreading of the rails. Thus, the shoes are maintainedin engagement with the rails when the safety device is operated.

Inasmuch as the safety brake can be released only by upward movement of the car, the danger attending release of a safety when the hoisting ropes are parted is eliminated. Also, with hoisting ropes intact, the release of the safety with fully loaded car or with the car in a blind portion of the hatchway is insured.

Although described as applied to an elevator car, it is to be understood that the safety brake may also be used on the counterweight.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in'the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In an elevator system having a body mov able in the elevator hatchway, a rail extending longitudinally of the hatchway and a safety device for said movable body, said safety device comprising; a member suspended beneath said body adapted to move upwardly with respect thereto; means carried by said member for engaging said rail; operating means for said rail engaging means carried by said member; resilient means interposed between said operating means and said body; and means operable during downward movement of said body for operating said operating means to effect the engagement of said rail engaging means with said rail to retard said member in its downward movement, decreasing the distance between said member'and said body, said resilient means acting upon said decrease in distance between said member and said body to transmit force due to the weight of said body to said operating means.

2. In an elevator system having a body movable in the elevator hatchway and a guide rail said rail engaging means also carried by said member; a spring interposed between said operating means and said body; and means operable during downward movement of said body for operating said operating means to effect the engagement of said rail engaging means with said guide rail to retard said member in its downward movement, said spring acting upon retardation of said member to transmit force due to"the weight of said body to said operating means.

3. In an elevator system having a body movable in the elevator hatchway and a guide rail for said movable body, a safety device for said movable body, said safety device comprising; a

member suspended from said body with a certain amount of clearance between them so as to permit upward movement of said member toward said body until said clearance is completely taken up; means for engaging said guide rail;

operatingmeansfor said rail engaging'means carried by said member; a spring interposed be,- tween .said operating means and said body; and means operable. during downward movement .of said bodyfor operating said operating means to effect'theengagement of said rail engaging means with said guide rail to retard said member in its downward. movement, decreasing the distance between said member and said body, a force due to the .weight of said body'being transmitted through said spring to said operating means, as soon as retardation of said member takes place, to increase the force with which said rail engaging means engages the; rail, which transmitted force increases as the distance between said member and said body further-decreases until the-clearance between said member and said body is,completely taken up, whereupon said body and member are retarded as a unit, by the engagement of saidrail engaging means with said rail, with a; retarding force which is in accordance with the compression of said spring. 7 V I 3 4. In an elevatorsystem having a body movable in the elevator hatchway and a guide rail for said movable body, a safety device for said movable body, said safety device comprising; a member suspended from said body for upward movementwith respect thereto; means for lime itingthe amount of such upward movement; a lever fulcrumed on said member; means carried by said member and operable by one arm of said lever, upon movement of said lever about its fulcrum in a certain direction, to engage said guide rail; a spring between the other arm of said leverand said body; and means operable during,

thereafter acting through said spring. and lever to increase the force with which said rail engaging means engages the rail as the distance between said member and said body decreases untilmovement of said member toward said body is terminated by saidlimiting means, at which point ,the force with which said rail engaging means engages said rail is in accordance with the force exerted by said spring. j 5. Inanelevator systemhaving a body movable inthe elevator hatchway and a guide rail for said movable body, a safety device for said movable body, said safety device comprising; a member suspended from said body for upward movement with respect thereto; means for limiting the amount of such upward movement;

jaws carried by said member for gripping said guide rail; operating means for said jaws adapted to be moved between the inner ends thereof to cause said jaws to grip the guide rail; a lever carried by said member, one arm of said lever carrying said operating means; a spring between the other arm of said lever and said body; and

,means operable-during downward movement of jsaid-body to liftsaid member toward said body,

the lifting of said member moving said lever in a directionto force said operating means betweenthe inner ends of said jaws, thereby causing the jaws to grip the guide rail to retard said member in its downward movement and further decrease the distance between said member and -=said body, said body thereafter acting through said springandlever to increase the force with which-the jaws are applied to the rail as the distance between said member and; said body decreases until movement of said member toward said body is terminated by said limiting means, whereupon'said body and said member are retarded as a unit with a retarding force which is in accordance with the compression of said spring. 1

6; In an elevator system having abody movable in the elevator hatchway and guide rails for said movable body, asafety devicefor said-movablebody, said safety device comprising; a cross memberextending between said guide rails; means for suspending said cross member from said body with a certain amount of clearance so as to permit upward movement of said member toward said body; means for engaging each of said guide rails; operating means for each of said rail engaging means carried by said cross member; means connecting each operating means to said body so as to prevent operation thereof when said cross member is not lifted oil its suspending means; and means operable during downward movement of said body to lift said cross member off its suspending means, the lifting of the cross member operating said operating means to effect the engagement of said rail engaging means withsaid guide rails to retard said cross member in its downward movement, said body thereafter acting through said connecting means and said'opera'ting means to cause force due to the weight of said body to be transmitted to said rail engaging means;

'7. In an elevator system having a body movable in the elevator hatchway and guide rails for said movable body, a safety device for said movable body, said safety device comprising; a cross member extending between said guide raiis; means for suspendingsaid cross member from said body with a certain amount of clearance between them so as to permit upward movement of said cross member toward said body until said clearance is taken up; means for engaging each guide rail; operating means for each rail engaging means carried by said cross member; a spring for each operating means, said springs being interposed between their respective operating means and said body; and means operable during downward movement of said body for operating said operating means to eifect the engagement of said rail engaging means with said guide rails, thereby retarding said cross member in its downward movement and decreasing the distance between said cross member and said body, a force due to the weight of said body being transmitted through said springs to said operating means, as soon as retardation of said cross member takes place, to increase the force with which said rail engaging means engage the rails, which transmitted force increases as the distance between said cross member and said body is further decreased untilthe clearance between said cross member and said body is completely taken up, whereupon said body and said cross member are retarded as a unit with a retarding force which is in accordance with the compression of said springs.

8. In an elevator system having a body movable in the elevator hatchway and guide railsfor said movable body, a safety device for said movable body, said safety device comprising; a cross member extending between said guide rails; means for suspending said cross member from said body so as to permit upward movement of the cross member toward said body; means for engaging each guide rail; operating means for each guide rail engaging means carriedby said cross'member; means for connecting said operating means to said body; means for lifting said cross member; means acting during downward movement of said body to operate said lifting means to lift said cross member toward said body, said operating means being operated by the lifting of said cross member to move said rail engaging means into engagement withsaid guide rails; and means for insuring both ends of said cross member being lifted equal amounts to insure the engagement of both guide rails by said rail engaging means.

9. In an elevator system having a body movable in the elevator hatchway and guide rails for said movable body, a safety device for said movable body, said safety device comprising; a cross member extending between said guide rails; means for suspending said cross member from said body so as to permit upward movement of the cross member toward said body; means for limiting the amount of upward movement of said cross member with respect to said body; means for engaging each guide rail; operating means for each guide rail engaging means carried by said cross member; means for connecting said operating means to said body; a pair of levers, pivotally supported on said body and connected to said cross member; means acting during downward movement of said body to move said levers in a direction' to lift said cross member toward said body, said operating means being operated by the lifting of said cross member to force said rail engaging means into engagement with said guide rails; and

lation to insure the engagement of both guide rails by said rail engaging means.

10. In an elevator system having a body movable in the elevator hatchway and guide rails for said movable body, a safety device for said movable body, said safety device comprising; a cross member extending between said guide rails; means for suspending said cross member from said body with a certain amount of clearance between them so as to permit upward movement of said cross member toward said body until said clearance is taken up; means for engaging each guide rail; operating means for each rail engaging means carried by said cross member; a spring for each operating means, said springs being interposed between their respective operating means and said body; means operable during downward movement of said body for operating saidoperating means to effect the engagement of said rail engaging means with said guide rails, thereby retarding said cross member in its downward movement and decreasing the distance between said cross member and said body, a force due to the weight of said body being transmitted through said springs to said operating means, as soon as retardation of said cross member takes place, to increase the force with which said rail engaging means engage the rails, which transmitted force increases as the distance between said cross member and said body is further decreased until the clearance between said cross member and said body is completely taken up, whereupon said body and said cross member are retarded as a unit with a retarding force which is in accordance with the force exerted by said springs; .and means for equalizing the force transmitted through each of said springs to said operating means for which the spring is provided.

11. In an elevator system having a body movable in the elevator hatchway and guide rails for said movable body, a safety device for said movable body, said safety device comprising; a

cross member extending between said guide rails; means for suspending said cross member from said body so as to permit upward movement thereof toward said body; means for limiting the amount of such upward movement; means for engaging each guide rail; operating means for each rail engaging means carried by said cross member; a spring for each operating means; and means operable during downward movement of said body for operating said operating means to effect the engagement of said rail engaging means with said guide rails, thereby retarding said cross member in its downward movement and decreasing the distance between said cross member and said body, said springs being arranged between their respective operating means and said body in such manner that a decrease in the distance between said cross member and said body causes a force due to the weight of said body to be trans mitted through said springs to increase the force with which said rail engaging means engage the rails, which transmitted force increases as the distance between said cross member and said body is taken up until movement of said cross member toward said body is terminated by said limiting means, whereupon said body and said cross member are thereafter retarded as a unit with a retarding force which is in accordance with the compression of said springs.

12. In an elevator system having a body movable in the elevator hatchway and guide rails for said movable body, a safety device for said movable body, said safety device comprising; a cross member extending between said guide rails; means for suspending said cross member from said body so as to permit a limited amount of upward movement thereof with respect to said body; means for each guide rail, carried by said cross member, for engaging that guide rail; an operating lever for each rail engaging means, carried by said cross member; a spring for each lever, each spring being interposed between one arm of the lever for which it is provided and said body; and means for moving each of said levers in a direction to effect the engagement of said rail engaging means for which the lever is provided with the guide rail, thereby retarding said cross member in its downward movement, decreasing the distance between said cross member and said body, said body thereafter acting on said levers through said springs to increase the force with which said rail engaging means engage the rails as the distance between said cross member and said body is taken up until movement of said cross member toward said body is terminated, whereupon said body and said cross member are thereafter retarded as a unit.

13. In an elevator system having a body movable in the elevator hatchway and guide rails for said movable body, a safety device for said movable body, said safety device comprising; a cross member extending between said guide rails; means for suspending said cross member from said body so as to permit upward movement thereof toward said body; means for limiting the amount of such upward movement; rail engaging means for each guide rail carried by said cross member; a pair of levers, one for each railenguide rail f-or'whichsuch means is provided; a

spring for each lever, each spring being'between .the other arm of:its1lever and said body; and

means operable during downward movement of said body forv moving each of said levers in said direction to effect the engagement'of the corresponding rail engaging means with the guide rail for which such means is provided, thereby retarding said cross member in its downward movement, decreasing the distance between said cross member and said body, said body thereafter acting on said levers through said springs to increase the force with which said rail engaging means engage the rails as the distance between said cross member and said body is taken up until movement of said cross member toward said body is terminated by said limiting means, at which point the amount of retarding force is in accordance with the compression of said springs.

' 14. In an elevator system having a body movable in the elevator hatchway and guide rails for said movable body, a safety device for said movable body, said safety device comprising; a cross member extending between said guide rails; means for suspending said cross member from said body so as to permit upward movement thereof toward said body; means for limiting the amount of such upward movement; means carried bysaid cross member for grip-ping each guide rail; means for operating each gripping means; a pair of levers, one for each gripping means, carried by said cross member, one arm of each lever carrying the operating means for the gripping means for which the lever is provided;

'a spring for each lever, each spring being between the other arm of its lever and said body;

and means operable during downward movement of said body to move each of saidlevers in a direction to cause operation of said gripping means by said operating means to grip the guide rails and thus retard said cross member in its downward movement, decreasing the distance between said cross member and said body, said body thereafter acting on said levers through said springs to increase the force with which said gripping means grip the rails as the distance between said cross member and said body is taken up until movement of said cross member 'toward said body is terminated by said limiting means, at which point the amount of retarding force is in accordance with the compression of said springs.

15. In an elevator system having a body movable in the elevator hatchway and guide rails for said movable body, a safety device for said movable body, said safety device comprising; a cross member extending between said guide rails; means for suspending said cross member from said body so as to permit upward movement thereof toward said body; means for limiting the amount of such upward movement; means carried by said cross member for gripping each guide rail; means for operating each gripping means; a pair of levers, one for each gripping means, carried by said cross member, one arm of each lever carrying the operating meansfor the gripping means for which thelever'is provided; a spring for each lever, each spring being arranged under compression between the other arm of its leverand said body; meansrfor equalizing the forces exerted by said springs on their respective operating levers; and means operable during downward movement of said body to move each of said levers in a direction to cause operation of said gripping means by said operating means to grip the guide rails and thus retard said cross member in its downward movement, decreasing the distance rbetween said .cross member and said body, said body thereafter acting on said levers through said springs to increase the force with which said gripping means grip the rails as the distance between said cross member and said body is taken up until movement of said cross member toward said body is terminated by said limiting means, at which point the amount of retarding force is in accordance with the compression of said springs.

16. In an elevator system having a body mov- 10 able in the elevator hatchway and guide rails for said movable body, a safety device for said movable body, said safety device comprising; a cross member extending between said guide rails; means for suspending said cross member from said body so as to permit upward movement thereof toward said body; means for limiting the amount of such upward movement; two pairs of jaws, one pair for each guide rail, pivotally supported on said cross member; a pair of wedges, one for each pair of jaws, each adapted to be moved between the inner ends of the jaws for which provided to cause said jaws to grip the guide rail; a pair of levers, one for each pair of jaws, fulcrumed on said cross member, one arm of each lever carrying the wedge for the jaws for which the lever is pro-- vided in position to move the wedge between the inner ends of such jaws; means connecting the other arm of each lever to said body thereby to hold said levers in position where the jaws are not applied to said rails by said wedges; and means operable during downward movement of said body to lift said cross member oif its susapending means, the lifting of the cross member moving said levers about their fulcrums in a direction to force the wedges between the inner ends of their respective pairs of jaws, thereby causing the jaws to grip the guide rails to retard said cross member in its downward movement and further decrease the distance between said cross member and said body, said body thereafter acting through said connecting means to increase the force applying the jaws to the rails until movement of said cross member toward said body is terminated by said limiting means.

1'7. In an elevator system having a body movable in the elevator hatchway and guide rails for said movable body, a safety device for said movable body, said safety device comprising; a cross member extending between said guide rails; means for suspending said cross member from said body so as to permit upward movement thereof toward said body; means for limiting the amount of such upward movement; two pairs of jaws, one pair for each guide rail, pivotally supported on said cross member; operating means for each pair of jaws adapted to be moved between the inner ends thereof to cause the jaws to grip the guide rail; a pair of levers, one for each pair of jaws, carried by said cross member, one arm of each lever carrying the operating means for the jaws for which the lever is provided in position to move such means between the inner ends of such jaws; a spring for each lever, each spring being between the other arm of its lever and said body; and means operable during downward movement of said body to lift said cross member off its suspending means, the lifting of the cross member moving each of said levers in a direction to force the operating means between the inner ends of their respective pairs of jaws, thereby causing the jaws to grip the guide rails to retardsaid cross member in its downward movement and further decrease the distance between said cross member and said body, said body thereafter acting on said levers through said springs to increase the force with which the jaws are applied to the rails as the distance between said cross member and said body is taken up until movement of said cross member toward said body is terminated by said limiting means, at which point the amount of retarding force is in accordance with the compression of said springs.

18. In an elevator system having a body movable in the elevator hatchway and guide rails for said movable body, a safety device for said movable body, said safety device comprising; a cross member extending between said guide rails; means for supporting said cross member from said body so as to permit upward movement thereof with respect to said body; means for limiting the amount of such upward movement of said cross member; means carried by said cross member at each end thereof adapted upon operation to grip the guide rails; a member for each gripping means movable to operate the same; a pair of levers, one for each movable member, each lever being pivotally mounted on said cross member and one arm of each lever carrying the movable member for which provided; means including a spring for each lever for connecting the other arm of each lever to said body; a pair of additional levers, pivotally supported on said body and connected to said cross member so as to move the same upwardly with respect to said body; and means acting during downward movement of said body to move said additional levers in a direction to lift said cross member off its suspending means, the lifting of the plank moving the first named levers about their pivots in a direction to move said movable members to operate said gripping means, causing them to grip the guide rails to retard said cross member in its downward movement and lift said cross member, said body thereafter acting on said first named levers through said springs to increase the force means, whereupon said body and said cross member are retarded as a unit.

19. In an elevator system having a body movable in the elevator hatchway and guide rails for said movable body, a safety device for said movable body, said safety device comprising; a plank extending between said guide rails; means for suspending said plank from said body so as to permit upward movement of the plank toward said body; means for limiting the amount of upward movement of said plank with respect to said body; two pairs of jaws, one pair for each guide rail, pivotally supported on said plank; a pair of wedges, one for each pair of jaws, each adapted to be moved between the jaws for which provided to cause said jaws to grip the guide rail; a pair of levers, one for each pair 'of jaws, each lever being pivotally mounted on said plank and one arm of each lever carrying the wedge for the jaws for which the lever is provided in position to move the wedge between such jaws; means for connecting the other arm of each lever to said body; a spring interposed in each of said connections between the levers and said body; a pair of additional levers, pivotally supported on said body and connected to said plank; means for maintaining said additional levers in parallel relation; and means acting during downward movement of said body to move said additional levers in a direction to lift said plank off its supports, the lifting of the plank moving the first named levers about their pivots in a direction to force the wedges between their respective pairs of jaws, thereby causing the jaws to grip the guide rails to retard said plank in its downward movement and further decrease the distance between said plank and said body, said body thereafter acting through said connecting means, first named levers and wedges to transmit force due to the weight of said body to said jaws whereby further decrease in the distance between said plank and said body causes increase in the force applying said jaws to the rail, said retarding force being thereby increased as the distance between said plank and said body is taken up until movement of said plank toward said body is terminated by said limiting means.

20. In an elevator system having a body movable in the elevator hatchway and guide rails for said movable body, a safety device for said movable body, said safety device comprising; a plank extending between said guide rails; means for suspending said plank from said body so as to permit upward movement of the plank toward said body; means for limiting the amount of upward movement of said plank with respect to said body; two pairs of jaw members, one pair at each end of said plank, the jaw members of each pair being pivotally supported between their ends on said plank and having their jaw ends embracing the sides of the guide rail at the end of the plank at which the jaw members are located; a roller mounted on the other end of each jaw member; a pair of wedges, one for each pair of jaw members, each adapted to be moved between the rollers on said other ends of the jaw members for which provided to force said jaw ends of such jaw members into engagement with the guide rail; a pair of bell crank levers, one for each pair of jaw members, each bell crank lever being pivotally mounted on said plank and one arm of each lever carrying the wedge for the jaw membore for which the bell crank lever is provided in position to move the wedge between the rollers of such jaw members upon movement of the bell crank lever in a certain direction about its pivot; means for each bell crank lever for connecting the other arm of that lever to said body; a pre-compressed spring interposed in each of said connections between the bell crank levers and said body; a pair of levers, one for each end of the plank, pivotally supported on said body, and connected to said plank; means for maintaining the second named levers in parallel relation; and means acting during downward movement of said body to move said second named levers in a direction to lift said plank 01? its suspending means, the lifting of the plank moving said bell crank levers about their pivots in a direction to force the wedges between the rollers of the jaw members, thereby causing the jaw ends of the jaw members to grip the guide rails to retard said plank in its downward movement and further decrease the distance between said plank and said body, said body thereafter acting on the bell crank levers through said springs to increase the force applying the jaws to the rails as further decrease in the distance between said plank and said body takes place until movement of said plank toward said body is terminated by said limiting means, at which point the amount of retarding force is in accordance with the compression of, said springs which, after the retarding force reaches a predetermined amount, are further compressed as the distance between said plank and said body is being taken up.

FREDERICK HYMANS.