US2263468A

US2263468A - Variable leverage door lift device

Info

Publication number: US2263468A
Application number: US302297A
Authority: US
Inventors: Jerome J Oleksiw
Original assignee: American Car and Foundry Co
Current assignee: ACF Industries Inc
Priority date: 1939-11-01
Filing date: 1939-11-01
Publication date: 1941-11-18
Anticipated expiration: 1958-11-18

Description

Nov. 18, 1941. J. J. oLEKslw VARIABLE LEVERAGE D'ooR LIFT DJvIcE` 2 Sheets-Sheet l Il if INVENTOR :I0/els a. @dg ATTORNEY df-ame Filed Nov. 1, 1939 gli... x

iin

J. J. OLEKSIW VARIABLE LEVERAGE Doon LIFT DEVICE Nov. 1s, 1941.

Filed Nov. l, 1939 2 Sheets-Sheet 2 door travel.

Patented Nov. 18, 1941 VARIABLE LEVERAGE DOOR LIFT' DEVICE Jerome J. Oleksiw, Shamokin, Pa., assigner to American Car and Foundry Company, New York, N. Y., a ,corporation of "New Jersey y Application November i, 1939, serial No. 302,297 s Claims. (el. iis- 99)l This invention relates to doors in general and in particular to sliding doors which are normally held by frictional engagement with their track but may be raised on an antifriction device for horizontal sliding movement.

The majority of lift devices for sliding doors have had the force applied to the mechanism in a single direction regardless of the direction of A very few of the lift devices, however, have been made in which the force as applied to lift the door was in the direction of door movement, but in any case a definite fixed leveragewas utilized. This fixed leverage was sulcient to enable the average operator to lift the door under average conditions, but in case the door was frozen in place or the parts had become rusted, then it became impossible for the average operator to lift the door. It is an object, therefore, of the present invention to provide a door lift ydevice with the parts so arranged as to give a constantly varying leverage.

A further object of the invention is the pro- .Vision of an improved roller lift device in which the leverage varies from an inm'te value to a nite value, limited only by the ratio of the lengths of the links use.

A still further object of the invention is the provisionof a variable leverage door lift device in which the force applied to the handle to lift the door is always inthe same direction as that toward which the door is tov be slid and will at 'some point be 'equal ltothe force necessary to cause the sliding movement of the door.

AYet another object of the invention is the provision of avariable leverage door lift device in which the lowering motion of the raised door causes thedoor to rock toward the direction it has been moved,V that is, to rock toward closed and sealed position during'lowering and after vthe door has been slid into substantially closed' more clearly disclose the construction;

Fig. 2 is a sectional lview taken substantially -online 2-2 of'Figure 1;

Fig. 3 is -aplan view of the lift mechanism with the door housing being shown in section;

Fig. 4 is a view similar to Figure 1 but showing the door in araised position; i

to bottom rail 8.

Figure 1 but showing a modification of the construction; 1

Fig. 6 is an elevational view of the construction shown in Fig. 5 but with the parts in door raised position;

Fig. 7 is an elevational sectional view taken substantiallyon line 1 1 ofFig. 8 and showing a still further modication;

Fig. 8 is a sectional View taken substantially on line 8-8 of Fig. '7 but with the roller housing incomplete;

Fig. 9 is a plan view of theroller carriage used in the construction of Figs. 7 and 8, and

Fig. 10 is an elevational view of a small Vportion of the door bottom rail disclosing the manner in which the door is mounted on the roller carriage construction of Figs. '7, 8 and 9.

Referring now to the drawings in detail, it will be seen that the mechanism' has been applied to a `more or less conventional freight car door having a corrugated central panel 2 welded or otherwise secured to front stile 4, rear stile 6 and In the form illustrated this bottom rail is of downwardly facing channel form having its inner and outer flanges or legs I0 and I2 terminating in inner and outer reanges I4 and Iii-respectively adapted to normally rest in frictional engagement with an angular shaped track I8. It is, of course, obvious that any type of door may be used and that any type of bottom rail may also be used, but the type shown is preferable since it fully houses the lift mechanism and prevents entrance of foreign matter.

The door as shown in Figures 1 to 6 inclusive is mounted upon a roller carriage consisting of an intermediate connecting bar 20 joined at its ends by rivets or other means 2| to straps 22 oiset as at 24 and extended to receive therebetween a roller 26 rotatably mounted upon axle 28., The straps 22 are preferably oiset upwardly intermediate their ends in order that the bar 2D may be located as low as possible, thus lowering the center of gravity of the carriage and at the v45v same time providing clearances for the motion of themechanism. Each strap 22 is pierced intermediate its ends in order to receive pin 30 extending between the straps and rotatably carrying thereon a link 32 as clearly shown in Figures 1 to 4 inclusive. The lower end of this link is non-rotatably connected by means of pin or rivet 34 to a transverse pin 36 journaled at its ends in the downwardly directed flanges I0 and I2 of the bottom rail. One ofthese latter trans- Fig. 5 is apartial elevational view similar V1;() '55 verse pins may be made square as clearly shown in the left hand portion of Figures 1 and 4 and is extended outwardly beyond the flange l'2 of the bottom rail and has attached rigidly thereto an operating handle 40. This construction may be readily assembled by inserting the carriage cornplete with links into the bottom rail, after which the pins 36 are inserted and fastened by the pin or rivet 34 andv the operating handle secured to the transverse shaft which extends outwardly beyond the bottom rail.

The operation of the construction shown in Figures 1 to 4 is believed obvious, but assuming" the door to be in lowered position of. Figure 1` it may be raised to the position shown in Figure 4 by merely applying a force to the handle 4.0 in the direction toward which the door is to be moved. It should be noted that with the handle 40 vertical and at the start of the lifting motion the leverage is infinite and constantly varies as the handle is swung, that is, as the handle 40 starts its swing the Amoti-on of the pins 36- is tangent to the track and as it reaches the end kof its travel the pins are moving substantially perpendicular to the track. Iii-other words, the effective lever arm between the fulcrum 30 and. point.` of weight application 36 varies. from zero .to the length of' link .32 if this lin-k is moved tov ai hori- Zonta] position, while` the length ot the lever arm between the point of forceapplication` and the yfulcrurn remains constant;

In other words, the leverage wi-ll vary from an infinite to a finite valuelim-itedby the ratio of. the lengths; of. the links-used: In generalpractice, however'it isnot necessary toprovide rfor, such an extremeliftof. the door and accordingly thecarri-ageY maybe designed as illustratedand in this case the minimum nite. 'leverage i-sl limited by the; swing obtainable before; pin 36 strikes. the straps 2-2. It will' bey seen from liigir-reflV that as the door isY moved toward. a: closed position and then lowered that. thedoor will'. rock forward toward a further closed; position duri-ng the; lowering. ofV thev door; such a. motion: being dueto the; relation of the partsand to the fact that the friction` of the door on its pins is less than'. the

i friction between the carriage and track.

Irr the form shownby Figures 5l and 6 the maior portions are identicak with thatV just` described in connection with Figures l to. 4s and accordingly thesame. reference numerals: will.' be: used',A In` this form, howeven, tvvo.v holes. IIZfareV made in each strap.. and joined by an: opening 43., thus'. providingawindow like opening having two bearing portions in the lower surface thereof. Thelinks 32 are also provided with two holesf adaptedf. to receive. twto transverse pins; M... Except: for-.the changelin: the mounting of' the. links 512ir this modification is4 exactly the same. as that.: previously` described and will be assembled. andA operated in. the same manner. vHowever, there isA this. difference, theleverage varies from a small finite; value. to an increasednite value dependent upon: theratio of theflengths` of the links or upony theiswingperniitted the` pinA 3.6'. .The value `ofi the lower. nite leverage wil-l1 be dependent uponthe distance the pins lili. are-placed err.ei'tllier-*side'oiv the center line through the links; By this arrangementsof oifset pinsa greater Athrowl or litt may belobtained without necessitatinga great changeains the.l antifriction carriage, .the initial rotation-f starts about a'.v pin oiisetgironr the. center line,.not about a pin. on thez center.' liner- ..A j

In therorm shownirr "I: to:Y 1'0 inclusive i an. independentroller: 5U used.jnurnaled on a transverse pin 521 resting at its ends im the; side walls of a roller carriage 54. The inner wall of this roller carriage is formed with a projecting trunnion 56, while the outer wall is also provided with a projecting trunnion 58 formed integral with an operating handle 60. It should be noted that the

trunnions

56 and 58 are offset relative to the roller axis or axle and accordingly lany rocking motion given the handle will tend to rotate the axle about the

trunnions

56 and 58. Theentire unit may be readily inserted in the bottom rail of the door by lifting the unit into position with

trunnions

56 and 58 passing into vslots 62 and 64' formed respectively in the inner and outer flanges of the door bottom rail. Application of force to the handles in the direction of desired' door movement will automatically raise the door and no conscious lifting effort may be exerted by the operator.

In` each of the forms described application of force to the operating handle in the direction of desired door movement automatically applies a powerful leveragefto lift the door and this leverlage varies constantly decreasing with increased doorliftl It will be obvious that regardless ofthe proportioning of the parts there', will be some point. at which; the force applied to the handle wiil= be sufficient tof'cause the door toroll on the track and; this point will only be reached after the.) door has, been lifted a slight amount on the carriage or roller' for', as previouslystated; the

leverage decreases .either from an infinite' or extremely/small; finite value..v By making; the leverage variablevaaiyoperator will be able to exert an extremely powerful lifting leverage on the door torbreakfythe seal between theV door and car and vto: break any ice or othermatter that may be preventing the lift iof the door;

.While the; constructions shown have been described; more: or less in detaily it. will heobvious l that, various modifications, rearrangements-of partsl and"'changes. in construction rsuggest themselves to: persons. skilled in the art and. all 'such modiii'cations, rearrangements of parts and changesrrconstruction'are contemplated as Will tall within the scope of the appended' claims which define my invention.

- Whatisclaimedis: Y f

1f. Ini a lift'd'evice for sliding doors having the bottom portion normally rest-ingY ona' supporting track;l the combination offen `anti-"friction carriage, suspension links hanging from said carriage andconnected-L adjacent theifr lower -erids' to bottom portion normally resting on a supporting track, thefcombinatiorijoi" an anti-friction`l device including a frame and spaced' rollers, suspension links hanging vfrom said frame. and connected adjacent their. lowerfen'ds to the. lowerA portion or the door 'thereby suspending the. croori on.' said frame, 'and' an operating handle.V connected to a vertical plane common tov-both. whereby a-,variable leverage may be'exertedyronthe door to lift the same khiring Y shifting. of the, handles,

3=.. In a.; lif-tdevice forvslidi-ngA doors having a 3 bottom portion normally engaging a supporting track, the combination, of. anti-friction: cai:-

riageg, suspension links; rockablyj supported. ad-

jacent their upper ends on said carriage, means supporting said door in stable equilibrium on said links adjacent the lower ends thereof, and an operating handle secured to at least one of said last named means.

4. In a lift device for sliding doors having a bottom portion normally engaging a supporting track, the combination of a carriage mounted on anti-friction rollers, means suspended on said carriage and normally supporting said door at points beneath the carriage in stable equilibrium, and an operating handle rigidly connected to said suspension means.

5. In a lift device for sliding doors having a bottom portion normally resting on a supporting track, the combination of a carriage mounted on anti-friction rollers, suspension means connected to said carriage and supporting said door at points beneath the carriage, and an operating handle rigidly connected to said suspension means, said suspension means being Connected to the carriage by spaced trunnions located on each side of a vertical plane through the door support points.

6. In a lift device for sliding doors having a bottom portion normally resting on a supporting track, the combination of a carriage mounted adjacent its ends on rollers, a plurality of suspension links trunnioned on said carriage intermediate said rollers, means connecting the lower ends of said links and door, and an operating handle rigidly connected to at least one of said last named means and the adjacent link to rock the latter about its carriage trunnion.

7. In a lift device for sliding doors having a bottom portion normally resting on a supporting track, the combination of a carriage mounted adjacent its ends on rollers, a plurality of suspension links trunnioned on said carriage intermediate said rollers, means connecting the lower ends of said links and door, and an operating handle rigidly connected to at least'one oi said last named means and the adjacent link to rock the latter about its carriage trunnion, said last named means and trunnion for each link being located substantially in a Vertical plane containing the trunnion axis.

8. In a lifting device for sliding doors having a bottom portion normally 'engaging a track, the combination of an anti-friction carriage, suspension links hanging from said carriageV and connected adjacent their lower ends to the lower portion of the door thereby suspending the door on said carriage, an operating lever connected to the lower portion of one of said suspension links to shift the same, said lever extending in the same direction as the link to Which it is con nected and the relation of said link and lever being such that initial predetermined lift applied to said lever will result in dis'engaging said door from said track and further movement of said lever will cause said door to move in th'e direction of the lever movement.

JEROME J. OLEKSIW.