US2896908A - Fluorescent fixture hoist - Google Patents

Description

July 28, 1959 -R. H. STONE FLUORESCENT FIXTURE HOIST 2 Sheets-Sheet 1 Filed June 20, 1957 Rober/ h. Sfone INVENTOR July 28, 1959 R. I1. STONE FLUORESCENT FIXTURE HOIST 2 Sheets-Sheet 2 Filbd June 20, 1957 FIG. 9

Robert H Stone INVENTOR United States Patent ()fiice 2,896,908 Patented July 28, 1959 FLUORESCENT FIXTURE HOIST Robert H. Stone, Sonora, Calif.

Application June 20, 1957, Serial No. 666,904

Claims. (Cl. 254-1) This invention relates to hoist devices and more particularly to a device for positioning fluorescent fixtures.

It is an object of the present invention to provide a portable hoist having self contained bracket means for positioning any desired object, such as fluorescent fixtures for installation purposes.

It is another object of the present invention to provide a novel lift device having a plurality of telescoping members and manually operated means for eifecting a selective extension and retraction of such members.

It is a further object of the present invention to provide a lift device of the above type in which a normally flexible chain assembly has means for effecting an axial compressive force so as to effect the raising of the telescoping lift members.

Other objects of the invention are to provide a fixture hoist bearing the above objects in mind which is of simple construction, has a minimum number of parts, is inexpensive to manufacture and eflicient in operation.

For other objects and for a better understanding of the invention, reference may be had to the following detailed description taken in conjunction with the accompanying drawing, in which: v

Figure l is a perspective view of a fluorescent fixture hoist made in accordance with the present invention;

Figure 2 is a fragmentary view of a chain link assembly used for effecting the operation of the lift assembly shown in Figure 1, in a flexible condition;

Figure 3 is a view similar to Figure 2, showing the link chain in an axial compressive force transmitting position;

Figure 4 is an enlarged fragmentary cross sectional view taken along line 44 of Figure 2;

Figure 5 is a transverse cross sectional view taken along line 55 of Figure 3;

Figure 6 is an enlarged fragmentary cross sectional View of the manually operated means for effecting operation of the hoist shown in Figure 1;

Figure 7 is an end view of the apparatus shown in Figure 6;

Figure 8 is a view similar to Figure 6, showing the lift in a collapsed position; and

Figure 9 is an enlarged transverse cross sectional view taken along line 9-9 of Figure 6.

Referring now more in detail to the drawing, a hoist device 10 made in accordance with the present invention is shown to include a collapsible tripod type base 12 which supports a main cylinder 14 in an erect position. A plurality of associated telescoping cylinders 16a, 5, c are arranged for movement within the main cylinder 14 between an extended and a collapsed position in order to effect the raising and lowering of any desired type of bracket 20 having a depending ram or plunger 17. As is more clearly shown in Figures 6 to 9, the manually operated means 22 for selectively effecting the raising and lowering of the bracket 20 is shown to include an outwardly extending support bracket 23 adjacent to the upper extremity of the main cylinder 14 upon which a first drive sprocket 24 and associated sheave are secured to a transverse rotatably supported shaft 26. A substantially parallel base bracket 27 is also provided with a rotatable shaft 33 upon which a driven sprocket 28 and sheave 29 are secured, together with a drive pinion 30. A sprocket chain '31 is in meshing engagement with the respective sprockets 24, 28, and is adapted to transmit rotation therebetween in response to rotation of the handle 32 that is also secured to the transverse shaft 26 of the upper bracket 23.

A lift chain 34 is connected at one end by means of a link 35 to the drive chain 31 and at the other end is connected to the lower end of the ram 17. As will be hereinafter described, this lift chain 34 is so constructed that in response to upward movement thereof, the links become rigidly connected soas to be able to transmit an axial lifting force to raise a plunger 17 and associated telescoping members and brackets therewith. This chain 34 is guided for movement between a pair of associated drive sprockets 40, 41 each of which is rotatably supported upon a separate shaft 39, 42, respectively. A driven pinion 37 secured to a shaft 39 of the drive sprocket 40 is in meshing engagement with the drive pinion-30 carried by the sprocket shaft 33 so that the lift chain 34 is positively driven between the associated drive sprocket 40, 41, in response to rotation of the driven sprocket 28 and the drive pinion 30, as efiected through the rotation of the manually operated handle 32. With the lift in a collapsed position, as shown in Figure 8, the lift chain 34a is trained about the sheaves 25, 29 of the actuating assembly under the guiding action of the connecting link 35. Upon rotating the handle 32, the drive chain 31 not only effects the aforementioned rotation of the operating parts, but also dispenses the required amount of lifting chain 34 for raising the ram 17 to the desired height.

As is more clearly shown in Figures 2 to 5, the lifting chain 34 includes a plurality of identical links, all pivotally connected together. More specifically, each link includes a pair of spaced sides 45 that are rigidly connected together by a pair of longitudinally spaced parallel rods or pins 46, 47. The opposite ends 48 of the sides 45 are inwardly offset so as to be received between the spaced sides 45 of the next adjacent link. Each of the inwardly offset side portions 48 is provided with alongitudinal slot 49 which rotatably and longitudinally slida-bly receives the outermost pin 47 of the next adjacent link and a terminal recess 50 which releasably receives the innermost pin 46 when the adjacent links are disposed in a single plane and are being urged towards engagement with each other, as shown in Figures 3 and 5.

It will be noted that in the extended position, the lifting chain 34a is completely flexible in that there is only a single pivotal point of connection between each adjacent link. However, when the links are disposed in a single plane and a compressive force is exerted between any number of adjacent links, the innermost pin 46 of each link will be urged into the terminal recess 50 of the next adjacent link, whereby all of these adjacent links acting together constitute a single rigid link 34 for the purpose of eifecting a compressive axial force. Thus, as shown in Figures 6 to 8, as the flexible link 34a is fed between the associated drive sprockets 40, 41, of the lifting apparatus, the adjacent links are aligned with each other and a compressive force exerted therebetween so that they become rigidified as at 34 to elfectively raise the ram 17. Actually, all of the links between the drive sprockets 40, 41,-and the bottom of the ram 17 are maintained in this interlocked position until they are withdrawn downwardly between the drive sprockets during the lowering of the hoist. During such lowering operation, all of the links beneath the drive sprockets 40, 41 are permitted by gravity to separate from each other suificiently to disen 1:3 gage the innermost pins 46 from the recesses 50 of the adjacent links, whereby the lift chain 34a may then be trained about the respective sheaves 25, 29 as the handle 32 is rotated.

While this invention has been described in connection with the raising and lowering of fluorescent fixtures, it will be recognized that this lift may be applicable to substantially any structure Where a lifting and lowering operation is required.

While various changes may be made in the detail construction, it shall be understood that such changes shall be within the spirit and scope of the present invention as defined by the appended claims.

What I claim as new and desire to protect by Letters Patent of the United States is:

1. A lifting hoist comprising, in combination, a base, a main cylinder secured to said base, a plurality of telescoping members adjustably supported upon said base for movement between a retracted and an extended position, manually operated means for selectively effecting said movement of said telescoping members, said manually operated means comprising a lift chain having a plurality of pivotally connected links, one end of said lift chain being connected to the inner one of said telescoping members, drive means for effecting longitudinal movement of the opposite end of said lift chain, and means associated with adjacent ones of said links intermediate said one end of said lift chain and said drive means for rigidifying said pivotally connected links for exerting a compressive axial force therethrough, each of said links comprising a pair of identical sides each having a base and an inwardly offset end portion, an outermost and an innermost pin extending through the bases of each pair of sides, each said ofiset end portion defining a longitudinal slot and a 4 terminal recess, said outermost pin being slidably and pivotally received within the longitudinal slots of the inwardly offset portions of the next adjacent link, and said terminal recesses displaceably receiving the innermost pin of said next adjacent link.

2. The combination according to claim 1, wherein movement of each adjacent pair of links in opposite directions away from each other is operative to effect the release of said innermost pin of each next adjacent link from said terminal recesses of said one link.

3. The combination according to claim 2, wherein movement of each adjacent pair of links in Opposite directions toward each other in a single plane is operative to effect the engagement of said innermost pin of each next adjacent link within said terminal recesses of said one link.

4. The combination according to claim 3, further comprising sprocket means for controlling the direction of movement of said links, said sprocket means selectively guiding said links in said single plane.

5. The combination according to claim 4, further comprising manually operated crank means for operating said sprocket means.

References Cited in the file of this patent UNITED STATES PATENTS 244,323 Shaw July 12, 1881 553,650 Kingsland Jan. 28, 1896 602,403 Kunkel Apr. 12, 1898 989,389 Mohrstadt Apr. 11, 1911 1,070,167 Nitschke Aug. 12, 1913 1,685,697 Guerin Sept. 25, 1928 2,584,134 Knutson Feb. 5, 1952

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