|Publication number||US2560500 A|
|Publication date||Jul 10, 1951|
|Filing date||Jul 16, 1949|
|Priority date||Jan 24, 1948|
|Also published as||DE804461C|
|Publication number||US 2560500 A, US 2560500A, US-A-2560500, US2560500 A, US2560500A|
|Inventors||Frank Warry Reginald|
|Original Assignee||R F Warry Ltd|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (1), Referenced by (1), Classifications (5)|
|External Links: USPTO, USPTO Assignment, Espacenet|
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l R. F. WARRY SAFETY DEVICE FOR HOIST PLATFORMS Filed July 16, M349 jatented july l0,
SAFETY DEVICE FOR HOIST PLATFORMS Reginald Frank Warry, Twickenham, England,
assigner to R. F. Warry Limited, London, England, a British company Application July 16, 1949, Serial No. 105,118 In Great Britain January 24, 1948 6 Claims. l
This invention relates to safety devices for use Awith hoist platforms, lift cages and the like.
Various forms of safety devices have been proposed heretofore for use with platforms or cages of hoists, lifts and the like for the purpose of automatically arresting the descent of the platform or vcage in the event of a cable by which it is suspended and drawn along a hoist frame or guideways of a shaft breaking or coming adrift so that it loses its load-carrying tension. Such safety devices sometimes take the form of split cones accommodated in tapered sleeves, the cable being threaded through the split cone so that consequent upon fracture of the cable the cone produces a `wedging action on the cable. Also, cam actuated devices have been proposed hereto- 'fore adapted consequent upon the freeing of the tension of the cable from spring means associated with the platform or cage to seize or bite against the hoist frame or guideways in the lift shaft. These and other known previously proposed safety devices are generally of a somewhat complicated or expensive nature and frequently fail by reason of their becoming worn away and/or slipping relatively to the frame or guide.
The object of the present invention is to provide a highly positive, simple and very strong safety device suitable for use with hoists or lift cages in which the platform or cage travels along a vertical or nearly vertical frame. For example the present invention is particularly useful in connection with the form of hoist described in my application No. 18,270 of 1946 in which the platform of a transportable hoist carries rollers by which it is guided along the appropriate anglebar members of a girder type of hoist frame.
The present invention is broadly characterised in that the cable by which the hoist platform or lift cage, hereinafter referred to as the platform, is drawn upwards along guideways is operatively connected to the platform via an abutment member which, by the tension of the said cable is held against a locking member formed with abutments adapted, when the cable breaks or comes adrift, to bite against adjacent vertical guideways but normally held clear of said guideways, said locking member being held by the tension of the cable in the normal or inoperative position by engaging a stop on the platform, spring means yieldingly opposing the tension of the cable being provided across the locking member and the platform, and across the abutment member and the platform, and adapted upon the cable shearing or coming adrift to separate the abutment member and the locking memberV and to move the 2 locking member to engage its abutments with the guideways whereby the said stop will, under the iniiuence of the weight of the platform cause the abutments on the locking member to bite against the guideways to arrest the platforms descent.
In order that the invention may be clearl understood and readily carried into effect, a sheet of drawings is appended hereto illustrating an embodiment thereof, and wherein,
Figure 1 is a front broken elevation view showing the platform adapted to a hoist similar to that described in co-pending application No. 18,276 of 1946 and with the platform supported by the cable under normal conditions. Y
Figure 2 shows the relative positions of the platform and elements of the safety device immediately the cable breaks or comes adrift.
Figure 3 shows the safety device operative.
Figure 4 is a side elevation view of Figure l, and
Figure 5 is a broken perspective rear view showing the relative disposition of the parts immediately the cable breaks or comes adrift.
Referring to the drawings, the platform frame I has two angle bar rear uprights 2 and 3, diagonal struts 4 across the tops of the uprights and the platform frame I, angle cross bars 5, 6 and 'I welded to the uprights, and rollers 8 tracking the front angle bar members 9 and I il, of the main column of the hoist along which the platform is raised and lowered by suitable winding mechanism receiving a cable II guided over a pulley I2 and anchored at one end to the top of the column and at the other end to a winch drum in Well known manner the pulley I2 is supported within? the forked upper end of a rod I3 guided through o the transverse stay bars 5 and 6 and secured at itsl lower end in a lug I4 (see Figure 5) formed on a transverse bar I5, so that in effect the cableA I IA can be regarded as connected to the transversebar I5 for drawing the platform up the column bars 9 and I0.
` Two vertical coiled tension springs I6 and I'Iv are anchored at their lower ends to the platform I, e. g. to hooks I8 on the lower ends of the plat;
form uprights 2 and 3, the spring I'I being anchored to one end of the transverse bar I5 to which the cable receiving pulley I2 is connected, and the other end of this transverse bar which normally abuts against the adjacent edge of a gripper bar I 9 and the other coiled tension spring I6 being anchored by a U-shaped shackle or stirrup 20 to the adjacent end of the gripper bar,
the lower end of this latter coiled tension spring' I6 being anchored to the Aplatform and receiving the same load as the other spring I1 due to the tension of the cable I I by reason of the fact that the adjacent end of the transverse bar I5 abuts against the appropriate end of the gripper bar I9 as shown in Figure 1.
It will be appreciated that by reason of the rod I3 being guided through the two bars 5 and 6 the transverse bar I5 is always maintained horizontal, or normal to the main column, and consequently it will normally abut flush against and maintain the Igripper bar I9 horizontal as shown in Figure 1, a stop lug or block 24 on the platform upright 2, limiting the Itension on the springs I6 and I'I, this lug-or block 24 functioning as part of the means to bring the safety device into operation as hereinafter described.
The gripper bar I9 is provided with two abutments 2l and 22 adapted to engage the said angle-section front bars 9 and I0 of the hoist column when the cable breaks or comes adrift, and. the abutment 22 on the gripper bar I9 at theend adjacent the end of the transverse bar I5 to which the coiled tension spring II is anghored is of wedge or Acube form with one edge ngr-mally slightly spaced from the adjacent hoist frame member I0. The other abutmentf2I, i. e. the abutment on the end of the bar I9 to which tliekother coiled tension spring I6 is anchored preferablyV has a polygonal, e. g. hexagonal periphery, to engage the column frame member 9-- and isnormally clear of the member 9 but is adapted to provide a fulcrum point about which the gripper bar I9 can swing through a small angle into acute angular relationship with the transverse bar I5 ,when the safety device comes into operation as shown in Figures 2 and 3.
The median part of the gripper bar I9 is formed with a V-shaped notch 23, or with a proud inverted V-shaped projection normally resting over a fulcrum pin 24 xed to the centre of the cross bar 5 of the platform frame.
, Welded onto,or otherwise fixed to, the vertical frame member 2 of the platform adjacent the end of the ,gripper bar `I 9 to which the appropriate coiled tension spring I6 is anchored is the aforesaid stop lug or block 24, and this is adapted, in the event of the cable breaking or coming adrift, to yultiniately abut against the upper edge of the latter end of the gripper bar I9 as shown in Figure 3, the/arrangement lbeing such that immediately the cable II breaks, or comes adrift, the vgripper bar I9 is pulled about the fulcrum pin 24 by the spring I6 into anl inclined or diagonal position relatively to the platform as shown in Figure 2 resulting in the edge of the abutment -2I on the [bar I9 engaging the associated hoist column member 9 and the other abutment 22 biting by a corner against the associated hoist columnmember I0. Immediately after the bar I9 has moved into this diagonal position the fulcrum pin 24' leaves the inverted v-shaped notch 23 of the bar I9 as shown in Figure 3, this being due to a slight displacement of the platform relatively to the gripperv bar, the lug or block 24 being carried by the weight of the platform hard against the `appropriate end ofthe gripper bar so that the gripper bar becomes wedged diagonally across the frame members 9 and IIJ of the hoist and thereby affords a highly positive gripping means preventing further descent of the platform, it being apparent that the heavier the lead on the platform the greater the grip of the said abutments against lthe frame members.
l. In combination a khoist column incorporating guides, a platform, a cable from which the platform is suspended and by which it is pulled up and lowered down the guides, a locking bar carried by and displaceable relative to the platform and spanning the said guides, relatively fixed abutments on said bar disposed adjacent to but normally not positively engaging the guides so that the locking bar is normally inoperative, means on the platform to actuate the locking bar to the operative position and normally subjected to the tension of the cable and thereby maintaining said locking bar in the said inoperative positional relationship with the platform and guides but adapted upon the cable shearing or coming adrift to cause a tilting of said locking bar to bring ksaid abutments hard against the guides and thereby to lock the platform against further descent.
2. In a hoist in which a cable suspends a hoist platform and is connected to winding means for dra-wingrthe platform, along guideways of .the hoist, safety-means to lock the platform against descent in the event of the cable breaking o r coming adrift, said Vsafety means comprising a cable anchorage member carried by the platform and a locking bar spanning the said guideways, abutments on said bar adapted, when the cable breaks or cornes adrift, to bite against the said guideways but normally held lclear of said guideways, a stop for the locking bar on the platform, said anchorage member under the tension vof the said cable being held against the locking bar to hold the locking bar due to the tension of the cable `in the normal or inoperative position against said stop on the platform with the abutments on the bar notmbiting against the guideways, spring meansyieldingly opposing the tensipn of the cable being yprovided across the locking bar and the platform, and across the anchorage member and the platform, and adapted upon the cable shearingor coming adrift to separate the -anchorage member and the locking bar yto movethe llocking bar` to engage its abutments with the guideways whereby the said stop will, under the influence of the weight of the platform, cause thelocking bar to tilt to cause the abutments on the locking bar Vto biteagainst the guideways to arrest the platforms descent.
3. In combinationa hoist column with guideways, a Aplatform running -up and down the guideways, a cable by which the platform is connected to the power driven means for raising and lowering the platform, a gripper bar loosely spanning vthe Vertical .guideways and formed with abutments which .during the normal raising and lowering of -the'platform havea slight clearance from the said guideways, spring means tending to displace the saidl gripper bar from its aforesaid normal or inoperative position into an inclined position relatively to the platform so as to engage the abutments on the gripper bar with the, said guideways, `,whereby due to the said inclination of the gripper bar and the weight of the platform the gripper bar becomes wedged across the guides or appropriate frame members to arrest descent of the platform, and a connection from the cable tothe said spring means which normally overcomes the aforesaid tendency of the spring means to displace said gripper bar into the .operative position.
4. A, safety device for use with up and down travelling `platforms of hoists in which the hoist embodies vertical-frame elements forming a column and in which the platform is pulled up and lowered down parallel guideways of the column by a cable adapted to be driven from a power unit, comprising a tiltable locking bar connected, but angularly displaceable relative, to the platform and common to and overlapping vertical frame elements of the column, relatively fixed abutments on said locking bar between which the latter frame elements are located, the abutments normally being disposed close to but clearing said latter frame elements, spring means tending to tilt said locking bar relative to the platform so as to cause the said abutments to bite hard against the said latter frame elements and to seize the bar immovably across such frame elements to arrest descent of the platform, and` a connection from the cable to said spring means which normally overcomes the aforesaid tendency of the spring means to displace the said locking bar into the operative position.
5. A safety device for hoist platforms in which a cable carried up the hoist from the platform is connected to the power operated means for raising the platform along parallel guides of the hoist, comprising a substantially horizontal abutment bar carried by the platform and disposed across one face of the parallel guides and to which the cable is connected to apply lift to the platform, spring means connected across one end of this abutment bar and the platform, a locking bar fulcrumed between its ends to the platform frame, and located above and engaged by said abutment bar so that normally the abutment barlies flush against the parallel superposed locking bar, further spring means to which the end of this locking bar remote from the spring loaded end of the abutment bar is connected to the platform, both of said spring means combining to yieldingly oppose the cables tension, the platform having a relatively fixed stop normally engagingthe upper edge of the locking bar and between which and the abutment bar the spring loaded end of the locking bar is located, two abutments on the locking bar disposed close to but normally spaced beyond the e-dges of the said parallel guides against which they are adapted to bite when the cable shears or comes adrift due to the weight of the platform being applied to the spring loaded end of the locking bar by said stop, said fulcrum of the locking bar affording a centre of leverage for such bar when the spring means loading the locking bar is permitted to reassert itself but the locking bar being freed from its fulcrum consequent upon the full weight of the arrested platform wedging the abutments on the locking bar against the guides.
6. A safety device to arrest descent of a hoist platform down guideways of the hoist consequent upon the shearing or coming adrift of a cable of the hoist by which the platform is connected to means for pulling it up and lowering it down the platform, comprising a locking bar with two relatively fixed abutments and carried relatively tiltably by the platform and spanning the guideways, spring means receiving the lifting tension of the cable and normally maintaining the locking bar in such position that its abutments are located close to but spaced from the guideways, and adapted consequent upon the tension of the cable being released therefrom to assert itself to tilt the locking bar so as to bite its said abutments against the guideways and arrest-the descent of the platform.
RE GINALD FRANK WARRY.
REFERENCES CITED UNITED STATES PATENTS Name Date Hinkel Dec. 1'7, 1907 Number
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US874339 *||Feb 19, 1907||Dec 17, 1907||Peter Hinkel||Elevator.|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US7591190 *||Feb 27, 2006||Sep 22, 2009||American Fabricating, Llc||Test stand|
|International Classification||B66B5/16, B66B5/18|