US3415343A - Catch apparatus for the cages of scaffold elevators and the like - Google Patents

Description

T. SVENSSON Dec. 10, 1968 Filed April 18, 1967 lllll'l F/Gl 3,415,343 CATCH APPARATUS FOR THE CAGES OF SCAFFOLD ELEVATORS AND THE LIKE Filed April 18, 1967 Dec. 10, 1968 .T. SVENSSON 7 Sheets-Sheet 2 A V//4 n W 4 @n 3 H s E a m r m 2 n V I a m 7. F w m 2 w m Fl n @1 w x n CATCH APPARATUS FOR THE CAGES OF SGAF'FOLD ELEVATORS AND THE LIKE Filed April 18, 1967 T. SVENSSON Dec. 10, 1968 '7 SheetsSheet 5 T. svENssoN CATCH APPARATUS FOR THE CAGES OF SCAFFOLD ELEVATORS AND THE LIKE Filed April 18, 1967 7 Shets-Sheef 4 FIG. 6

T. SVENSSON Dec. 10, 1968 CATCH APPARATUS FOR THE CAGES OF SCAFFOLD ELEVATORS AND THE LIKE 7 Sheets-Sheet 5 Filed April 18, 1967 T. SVENSSON Dec. 10, 1968 CATCH APPARATUS FOR THE CAGES OF SCAFFOLD ELEVATORS AND THE LIKE Filed April 18, 1967 7 Sheets-Sheet 6 T. SVENSSON Dec. 10, 1968 CATCH APPARATUS FOR THE CAGES OF scAFFoLD ELEVATORS AND THE LIKE Filed April 18, 1967 7 Sheets-Sheer. v

Patented Dec. 10, 1968 3,415,343 CATCH APPARATUS FOR THE CAGES F SCAF- FOLD ELEVATORS AND THE LIKE Torbjiirn Svensson, Skelleftea, Sweden, assignor to Alimak-Verken AB, Skelleftea, Sweden Filed Apr. 18, 1967, Ser. No. 631,805 11 Claims. (Cl. 187-19) ABSTRACT OF THE DISCLOSURE In scaffold elevators or the like, in which the elevator cage by means of a driven gear wheel climbs along a toothed rack in a mast structure, a centrifugal regulator and a drum brake are built as one unit attached to the cage, and the drum brake is successively braking the regulator shaft, which has a gear wheel meshing with the rack, thereby successively stopping the cage in relation to the rack by the aid of the apparatus frame and the regulator gear wheel meshing with the rack, without the aid of wedges or the like.

The invention refers to a catch apparatus (catch arrangement) for the elevator cages of scaffold elevators and other similar elevators, in which the elevator cage by means of a driven gear wheel climbs along a toothed rack in a mast structure for the elevator.

The catch apparatus for the elevators in scaffolds and the like are centrifugally controlled by a centrifugal regulator supported by an apparatus frame attachable to the main frame of the elevator cage, said centrifugal regulator having on its shaft a gear wheel meshing with the rack and governing the catching of the cage by clamping the same against a stationary part of the mast structure. Constructions of this type have the disadvantage that damages on bearing (supporting) parts of the structure may occur.

The object of the invention is to secure a catching with a successive or smooth (soft) action, yet having a safe and reliable function.

According to the invention, the centrifugal regulator is provided for causing, when exceeding a predetermined number of revolutions, an engagement of a drum brake or other similar rotary brake within a common regulatorand brake-casing which constitutes the apparatus frame attached to the main frame of the elevator cage, wherein the brake is provided for successively braking the regulator shaft and thereby stopping the elevator cage in relation to the rack by the aid of the apparatus frame and the regulator gear wheel meshing with the rack, thus without any utilization of wedges or the like.

On account of the tooth engagement between the rack and the gear Wheel supported by the regulator shaft, the function is rendered safe and reliable, as there is a positive transfer of the braking and catching force to the rack. At the same time, the utilization of a successively engaging brake will secure a smooth or soft catching. Moreover, according to the invention the centrifugal regulator and the catching device proper are built as one compact unit at the rack, this in contradistinction to the arrangements hitherto usual, in which the centrifugal regulator is located at another place.

In one embodiment of the invention, the drum brake is disposed concentrically around the regulator shaft and is slightly conical, and the drum which by means of rocking centrifugal bodies on the regulator shaft can be coupled to the same, is provided to be forced, when rotated from the regulator shaft, axially to engagement with the surrounding stationary brake member which is a part of the casing. Moreover, the inner brake drum when rotated from the regulator shaft is adapted to tension a spring by means of a feed screw and a screw sleeve, said spring acting axially upon the brake drum and forcing the same successively harder against the stationary member of the drum.

The embodiment stated above is advantageous in the most cases. However, in connection with especially large scaffold elevators, the counter weight is provided to balance not only the elevator cage but also approximately the half of the load or charge, and if in such cases there would occur a break in the transmission for the movement of the cage, the cage if empty could rush upwards. Therefore, in said cases there is a need of a facility for catching the elevator cages also when running upwards.

Thus, there is a related object of the invention to create an improvement in this repsect, viz. a double-acting catch apparatus, and this is possible by a simple modification of the embodiment indicated above.

The double-acting catch apparatus according to this further improvement is characterized in that the centrifugal bodies on the regulator shaft are provided for engagement with oppositely directed abutment surfaces on the inside of the brake drum in response to a rotation of the regulator shaft in different directions, and that two concentric screw sleeves are provided on a central journal on one end wall of the brake drum, the inner one of said two screw sleeves meshing both with the journal and with the outer screw sleeve by threads of oppositely directed pitch (right-handed threads and lefthanded threads), respective ones of said screw sleeves being axially movable by the journal. in either direction for tensioning a spring and thereby forcing the brake drum axially to engagement with the stationary member of the brake.

In this way, the rotatable drum is forced axially against the stationary member of the brake independent of the direction in which the regulator shaft is rotating above a predetermined number of revolutions.

According to a main feature of the present invention, as characterized above, the catching is effected by means of the gear wheel supported by the regulator shaft and meshing with the rack, and in large elevators carrying a full load or charge, the stresses on. the teeth can be rather high at the moment when the elevator cage is catched and stopped.

By a further improvement accordin to the present invention, the high load on the intermeshing teeth can be reduced to the half amount if two additional gear wheels are provided between the rack and the gear wheel supported by the regulator shaft, whereby the lastmentioned gear wheel does not engage directly in the rack but is catched by the rack through the aid of said two additional intermediate gear wheels, thus by a double teeth-engagement.

The invention will be more clearly explained in connection with three embodiments illustrated by way of example in the accompanying drawings, in which:

FIG. 1 is an isometric view of a portion of a scaffold elevator with a unidirectionally acting catch apparatus according to the invention;

FIG. 2 is an axial cross-section, on a greater scale, through the catch apparatus according to the first embodiment of the invention;

FIG. 3 is a vertical cross-section along the line IIIIII in FIG. 2;

FIG. 4 is a vertical cross-section along the line IV-IV in FIG. 2;

FIG. 5 is a fractional horizontal cross-section along the line VV in FIG. 4;

FIG. 6 is an axial cross-section through a doubleacting catch apparatus according to the second embodiment of the invention;

FIG. 7 is a vertical cross-section along the line VII-VII in FIG. 6;

FIG. 8 is a fractional side-view of a catch apparatus with double teeth-engagement according to the third embodiment of the invention;

FIG. 9 is a diagrammatic end-view corresponding to FIG. 8.

In FIG. 1, the reference numeral 1 indicates the elevator cage, 2 is the elevator mast, 3 the rack, 4 and 5 guiding rollers which are supported by the main frame of the elevator cage and which from different directions engage with adjacent posts of the elevator mast, 6 the clambing machinery mounted on the main frame of the elevator cage, 7 the driving motor of said machinery, 8 a counter roller mounted on the frame of the climbing machinery, 9 the driven gear wheel of the climbing machinery, said gear wheel meshing with the rack, 10 the casing of the centrifugal regulator and the drum brake, said casing also being mounted on the main frame of the elevator cage, and 11 the gear Wheel supported by the regulator shaft and also meshing with the rack.

As shown in FIGS. 2 and 3, the regulator shaft 12 which on its end supports the gear wheel 11, is within the surrounding widened portion 15 of the casing 10 provided with a yoke 18 which extends diametrically to the regulator shaft and is firmly supported by the same. At the ends, said yoke supports the two centrifugal bodies 17 by means of journals 16, said centrifugal bodies constituting bow-shaped arms, rockable on their journals. Through an opening in the regulator shaft, a draw spring 14 extends, interconnecting the two centrifugal bodies and tending to keep the same in an inner position, as seen in the radial direction. At a predetermined number of revolutions of the regulator shaft the centrifugal bodies 17 engage with projections 19 on the inside of the rotatable member 20 of the concentric drum brake 15, 20. Said rotatable member is made as an inner drum with an end wall having a central journal 21 with a bore, in which the inner end of the regulator shaft 12 is mounted. The stationary member 15 is formed of the abovementioned widened portion of the casing. An interchangeable brake lining 34 is provided between the brake mem bers 15, 20. The concentric brake members 15, 20 are slightly conical.

The brake drum 20 is axially movable within certain limits and is axially actuated by a pressure spring 22 which preferably is biased to a suitable degree of pretension. This spring is adapted to exert upon the brake drum an axially acting force for moving the brake drum to engagement with the stationary brake member 15. The central journal 21 on the end wall of the brake drum 20 has a feed screw portion 23 Which by means of the threads meshes with a non-rotatable but axially movable screw sleeve 37 for tensioning the spring 22 and forcing the brake drum 20 against the stationary brake member 15. Thus the brake drum 20, when rotated from the regulator shaft 12, will tension the spring 22 by means of the feed screw 23, whereby the spring 22 will force the brake drum 20 successively harder against the stationary brake member 15 until the rotation of the regulator shaft 12 has stopped.

As shown in FIGS. 2 and 4, the screw sleeve 37 is held against rotation by a ring 36, to which the sleeve 37 is secured by screw bolts 30 and which has a radial guiding pin 25 projecting through a longitudinally extending guiding slot 27 in the surrounding Wall of the casing 10. When the screw sleeve 37 with the ring 36 is moved axially for causing engagement of the drum brake (to the left in FIG. 2), the external end of the guiding pin 25 actuates, by means of an oblique camming surface, the control member of a switch 24, as shown in FIGS. 2, 4 and 5, whereby said switch interrupts the supply of current to the driving motor 7. After a catching operation,

the catch apparatus can be re-set to operative position by removing the cover 26 and the screw bolts 30, then screwing the sleeve 37 back to its initial positionwhile releasing the switch 24-and finally securing the sleeve 37 by means of the screw bolts 30 and mounting the cover 26.

The catch apparatus according to the invention secures a soft catching without jerks and is therefore especially well adapted for elevators with high speeds of the cage. The catching is not effected against any bearing (supporting) parts of the mast structure but only against the rack fixed to the mast. As the pressure spring has a pre-tension, the braking will start immediately upon the engagement of the centrifugal regulator, and then the 'braking force will increase successively. The braking of the cage is effected by the aid of interchangeable brake linings or brake straps of a material especially adapted for its purpose. The centrifugal apparatus and the catch apparatus constitute one common unit which is completely encased.

In FIGS. 6 and 7, similar reference numerals as in FIGS. 1 to 5 are used for corresponding parts 10, 11, 12, 13, 14', 15, 16', 17H, 17V, 18', 18", 19, 20, 21, 22, 23, 24, 25, 26, 30, 34, 36, 37.

According to FIGS. 6 and 7, the two centrifugal bodies 17H and 17V are made as bow-shaped rockable arms having one end mounted on journals 16' in the yoke 18 attached on the regulator shaft 12, and having the other ends oppositely directed, as seen in the direction of rotation. In response to rotation of the regulator shaft 12 in different directions, said centrifugal bodies engage with oppositely directed abutment surfaces, formed by the sides H and V, respectively, of the projections 19'. Moreover, resilient abutments 18" are provided for the pivoted ends of the centrifugal bodies, said abutments being disposed in the yoke and serving to sustain the centrifugal bodies when engaging the projections 19'. For instance. the pivoted ends of the centrifugal bodies can be arc-shaped and made to fit in corresponding recesses in the resilient abutments 18", said recesses having a somewhat smaller radius than the arc-shaped ends of the centrifugal bodies, then said resilient abutments consisting of rubber, a plastic or the like.

Between the screw sleeve 37 and the journal 23, in an annular space, there is provided a second screw sleeve 38 meshing by threads both with the journal 23 and with the first-mentioned screw sleeve 37, but by threads of opposite pitch, the screw sleeve 38 having left-handed threads on its outside and right-handed threads on its inside.

Now, if the regulator shaft 12 rotates in the right-hand direction above a predetermined speed, the centrifugal body 17H will engage with the surface H of one projection 19. During the continued rotation the spring 22 is compressed under the action of the internally right-handed screw sleeve 38, whereby the brake drum is forced against the stationary brake member 15, until the rotation of the regular shaft has stopped and the elevator cage has been catched by the gear wheel 11. If the regular shaft 12 rotates in the left-hand direction above a predetermined speed, the centrifugal body 17V will engage with the surface V of one projection 19'. During the continued rotation, the spring 22 is compressed under the action of the internally left-handed screw sleeve 37', whereby the brake drum 20 is forced against the stationary brake member 15, until the rotation of the regulator shaft has stopped and the elevator cage has been catched by the gear wheel 11.

Any free rotation of the screw sleeves 37' and 38 is prevented by the guiding pin 25 which is movable in a longitudinally extending guide slot in the surrounding wall of the casing 10. After a catching function, the catch apparatus can be re-set for a new catching operation by removing the cover 26 and the screw bolts 30, and then screwing the sleeve 37' or 38 back to its initial position.

Accordingly to FIGS. 8 and 9, the end of the stationary portion 15' of the casing supports, on its end plate 15", a support plate 40 with a yoke 41, in which two additional gear wheels 11b and 110 are mounted for free rotation and are disposed so as to mesh both with the rack 3 and with the gear wheel 11a supported by the regulator shaft. On account of these two intermediate gear wheels 11b and 11c the number of engagement points on the rack is doubled, whereby during catching the load at each teeth engagement at 11b and 110, respectively, is reduced to the half amount.

In the support plate 40 also an especial counter roller 42 for the regulatorand the catch-apparatus is mounted. A similar counter roller can be provided also in such cases, in which the gear wheel 11 supported by the regulator shaft meshes directly with the rack 3, that is when no additional intermediate gear wheels 11b, 110 are provided.

The provision of the two intermediate gear wheels can be utilized both in connection with the unidirectionally acting catch apparatus, for instance according to the first embodiment described above, and in connection with the double-acting catch apparatus, for instance according to the second embodiment described above.

I claim:

1. Apparatus for controlling the speed of an elevator cage in which the elevator cage is moved along a rack connected to the mast structure of the elevator by a driven gear, the improvement which comprises:

a centrifugal regulator mounted on the elevator cage and including a regulator shaft (12) having a gear (11) in mesh with the rack, said regulator further including,

rotary brake means disposed concentrically around the regulator shaft, said brake means including a stationary brake drum (15) and a rotatable brake drum (20) said brake drums being conically shaped so that the braking pressure exerted between the drums is increased by longitudinal movement of one drum with respect to the other;

centrifugal bodies (17) connected to the regulator shaft (12) for engaging and rotating said rotatable brake drum (20) at a predetermined number of revolutions per unit of time to cause braking of the regulator shaft and thereby braking of the elevator cage with respect to the rack; and

means (22) responsive to the rotation of said rotatable brake drum (20) for axially moving one conical drum relative to the other to further increase the braking pressure between said drums.

2. Apparatus as recited in claim 1 wherein said moving means comprises:

a threaded shaft (23) connected to said rotatable brake drum (20);

a threaded sleeve (37) mounted for axial movement on the shaft upon rotation of said rotatable brake drum (20); and

spring means (22) associated with said sleeve for exerting an increasing longitudinal force on said shaft and rotatable drum as said sleeve is threaded axially on the shaft to increase the braking pressure between said stationary drum (15) and said rotatable drum (20).

3. Apparatus as recited in claim 1 wherein said rotatable drum (20) concentrically positioned around the regulator shaft (12) is provided with inward projections (19) on itsinternal surface; and wherein said centrifugal bodies (17) project outwardly from the regulator shaft (12) at said predetermined number of revolutions a distance sufficient to engage the projections to cause rotation of the drum (20).

4. Apparatus as recited in claim 1 which further includes an interchangeable brake lining (34) positioned between said stationary brake drum (15) and said rotatable brake drum (20) 5. Apparatus as recited in claim 2 wherein said rotatable drum (20) is provided with an end wall having a 6 central journal (21) for supporting one end of said regulator shaft (12), and wherein said threaded shaft (23) and said regulator shaft (12) are coaxial.

6. Apparatus as recited in claim 1 wherein said rotatable drum (20) concentrically positioned around the regulator shaft (12) is provided with inward projections (19) on its internal surface, and wherein said centrifugal bodies 17H, 17V) on the regulator shaft include a mem her which extends outwardly so as to engage the projections (19) when the rotation of the regulator shaft in one direction exceeds a predetermined amount per unit time, and another member which extends outwardly so as to engage the projections (19) when the rotation of the regulator shaft exceeds a predetermined amount per unit time in the opposite direction.

. 7. Apparatus as recited in claim 6 wherein said movmg means comprises:

a threaded shaft (23) connected to said rotatable brake drum (20);

two concentric threaded sleeves (38, 37) mounted on said shaft (23) for axial movement, the inner one (38) of said sleeves being in engagement both with the shaft (23) and with the outer one (37) of said sleeves by threads of oppositely directed pitch; and

spring means (22) associated with said sleeves for exerting an increasing longitudinal force on said shaft and rotatable drum as said sleeves are moved axially on the shaft to increase the braking pressure between said stationary drum (15) and said rotatable drum (20) whereby rotation of said brake drum (20) in either direction causes one or the other of said sleeves to be advanced thereby forcing the brake drum (20) axially into engagement with the stationary brake drum (15).

8. Apparatus as recited in claim 1 wherein said centrifugal bodies are rockable arms (17H, 17V) having one end pivotally connected to said regulator shaft (12) and having the other ends oppositely directed, as seen in the direction of rotation.

9. Apparatus as recited in claim 8 wherein said rockable arms (17H, 17V) are connected to a yoke (18) mounted on the regulator shaft (12), and wherein said rockable arms are provided with resilient abutments (18") at the pivoted ends of the rockable arms.

10. Apparatus as recited in claim 1 which further comprises:

a pair of additional gear wheels (11b, 11c) positioned between the rack and said gear (11), each of said gear wheels (11b, being in mesh with the rack and said gear (11) on the regulator shaft for reducing the strain on the teeth of the various gears.

11. Apparatus for controlling the speed of an elevator cage in which the elevator cage is moved along a rack connected to the mast structure of the elevator by a driven gear, the improvement which comprises:

a centrifugal regulator mounted on the elevator cage and including a regulator shaft (12) having a gear (11) in mesh with the rack, said regulator further including,

rotary brake means disposed concentrically around the regulator shaft, said brake means including a stationary brake drum (15) and a rotatable brake drum (20) having inward projections (19) on its internal surface;

centrifugal bodies (17H, 17V) on the regulator shaft for engaging the projections 19 at a predetermined number of revolutions per unit of time to rotate the brake drum (20) and thereby cause braking of the regulator shaft, said centrifugal bodies including one member which extends outwardly so as to engage the projections (19) when the rotation of the regulator shaft in one direction exceeds a predetermined amount per unit time, and another member which 7 8 extends outwardly so as to engage the projections 509,976 10/1930 Germany. (19) when the rotation of the regulator shaft ex- 382,107 10/1932 Great Britain.

ceeds a predetermined amount per unit time in the opposite direction.

References Cited FOREIGN PATENTS US. Cl. X.R.

399,769 5/1908 France. 187-78; 188--184,187 200,281 4/1906 Germany.

EVON C. BLUNK, Primary Examiner.

5 H. c. HORNSBY, Assistant Examiner.

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