US2170595A - Lifting jack - Google Patents

Description

Aug. 22, 19 39. F. v. POVANDRA LIFTING JACK F'iled'April 22, 1938 2 Sheets-Sheet 1 N\ MN WM W.

ATTORNEYS Aug. 22, 1939.

LIFTING Filed April F. v. POVANDRA JACK 22, 1958 2 Sheets-Sheet 2 .Z' ZZZL J 2/ $25 37 5 Frail 1/ Pm/anJ/u 7 Z6 INVENTOR ATTORNEYS Patented Aug. 22, 1939 "UNITED STATES PATENT OFFICE 2 Claims.

My invention relates to lifting jacks and more particularly to that type wherein a plurality of pivoted members are employed for Varying the lifting height.

One of the principal objects of my invention is to provide a lifting jack equipped with a plurality of pivoted members operable for varying the height thereof.

Another object of my invention is to provide a'jack of'the' above described character which is simple in construction, durable in use, efficient in operation and economical in manufacture.

Other objects and advantages will be apparent from the following description, appended claims and annexed drawings.

Referring to the drawings wherein like reference characters designate like parts throughout the several views:

Figure 1 is a top plan view of my invention illustrating the support casing in section.

Figure 2 is a rear elevation, several of the parts being removed.

Figure 3 is a sectional view taken on the line 3-3 of Figure 2.

Figure 4 is a sectional View taken on the line 4-4 of Figure 3.

Figures 5, 6 and '7 are detail sectional views taken on the lines 5-5, 66 and l1 of Figure 4 respectively.

Figures 8 and 9 are detail sectional views taken on the lines 88 and 99 of Figure 1 respectively.

In practicing my invention I employ a base 5 integrally formed with a hollow support casing 6 having vertically and horizontally extending channels 6a and 61) respectively in which is slidably mounted a plurality of articulated members I. Said channels are connected together by an inflected section whereby to permit said members to be disposed in aligned position in said channels.

The articulated members I are each in the form of a link having a block portion 8 fashioned on an outer face with rack teeth 9 for engagement with gear teeth of a gear l0 fixed to a shaft ll journaled in a bearing l2 mounted on the casing 6 and a bearing l3 mounted on the base 5.

The links are also fashioned with bifurcated end portions for receiving reduced portions of the adjacent links and through which extend pintles I 4 whereby the links are pivotally connected together. The sides of the links are provided with wear plates l5 secured thereto by means of the pintles l4 and said wear plates are fashioned with slots l6 for embracing the ends of latch actuating members ll. The actuating members I! extend through the block portions 8 and are fashioned with offset sections l8 operable within transversely extending slots l9 formed in said portions 8. The block portions 6 8- are also fashioned with longitudinallyextending bores 20 having latch bolts 2! slidable therein.

Said latch bolts are provided with apertured headsZZ through-which extend the offset sections l8 of the members IT. The latch bolts are adapt- 10: ed to extend beyond the bores 20 and seat within similar bores 23 formed in the reduced portion of the adjacent link whereby to maintain the links in aligned position as hereinafter more fully described.

Formed on the members l1, within the slots l9, are yokes 24 having sliding connections with the ends of coil springs 25, the opposite ends of said springs being connected to the respective reduced portions by means of pins 26 as clearly 20 illustrated in Figures 4 and '7 of the drawings. The outer ends of the members I! are offset and extend at right angles relative to each other for engagement with projections 21 and 28 formed on the inner walls of the channel 6a.

The projection 21 extends in the path of one of the offset ends of the members I! and engages the latter to actuate the latch bolt into projected position when the links are moved upwardly within the channel 6a by the action of the gear 30 I0. When the gear I0 is operated in a reverse direction the projection 28 engages the opposite ends of the members I! when the links are moved downwardly thereby actuating the latch bolt to retracted position. As the links are moved up- 35 wardly in the channel to, the latch bolts are actuated to extended position to effect latching of the links with each other thereby preventing the links or members H from pivoting as they are moved upwardly out of the casing 6.

The base 5 is provided with a pair of bearings 29 in which is journaled a shaft 30 having fixed thereon a gear 3! meshing with a gear 32 fixed on the shaft ll through the medium of which the gear I 0 and members I are actuated. Also 45 fixed on the shaft 30 is a bevel gear 33 meshing with a similar gear 34 rotatably mounted on a shaft 35 and having connected thereto for movement therewith a brake drum 36 about which is positioned a brake band 31. 50

The shaft 35 is rotatably mounted in bearings 38 and has slidably connected thereon a clutch element 39 for engagement with a similar element 40 carried by the gear 34 whereby to connect said gear 34 and said brake drum 36 in operating condition with the shaft 35. A spring 4| is mounted on the shaft 35 and interposed between the clutch element 39 and the adjacent bearing 38 whereby to normally urge the clutch element 39 towards the element 40. An operating arm 42 connects the clutch element 39 to a shift arm 43, said shift arm being fashioned with a plurality of position grooves 44 in which a roller 45 is adapted to selectively seat.

The roller 45 is rotatably mounted within a yoke 46 carried on one end of an arm 4'! for actuating the brake band 31. The brake band 31 is fashioned with laterally extending spaced ends 48 and 49 connected together by means of a spring 58 for normally maintaining the brake in contracted condition about the drum.

The end 49 of the band is secured to a bracket mounted on the base 5. Each of the ends are provided with openings through which the arm 41 extends. The arm 41 is provided with a collar 52 for engaging the under face of the end 48 whereby when the arm 43 is shifted to raise the yoke 45, said collar will engage the end 48 and release the band 31 about the drum 36. Obviously, shifting of the arm 43 serves. to effect engagement of the clutch elements and a release of the brake drum. Shifting of the arm in an opposite direction serves to disengage the clutch elements and permit application of the brake. Further, shifting of the arm 43 to move the clutch elements still further apart serves to release the brake without effecting engagement of the clutch elements thereby permitting a lowering of the members 1 within the channel 6a. The shaft 35 is provided with end sections for receiving a crank or other similar tool for operating the device. However, it is to be understood that any other source of power, other than manual, may be used for operating the shaft 35.

The ends of the arm 43 are slidably mounted in bearings 53 secured to the base 5 whereby the arm 43 is maintained in the bearings 53 against vertical and lateral movement.

What I claim is:

1. A device of the character described, comprising, a base fashioned with a casing formed with a pair of connected channels, a plurality of articulated members movable in said channels, means for moving said members from one to another of said channels, latching devices carried within said members and equipped with elements extending through said members and terminating in angularly disposed ends without said members, and a projection formed on said casing within one of said channels for engagement with said ends whereby to operate said devices for maintaining said members in aligned condition after movement from one channel to another.

2. A device of the character described, comprising, a base fashioned with a casing formed with a pair of connected channels, a plurality of articulated members movable in said channels, means for moving said members from one to another of said channels, latching devices operable for maintaining said members in aligned condition after movement from one channel to another, and a fixed projection on said casing and disposed in one of said channels for engagement with said devices for operating the latter.

FRANK V. POVANDRA.

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