US1052913A - Lifting-jack. - Google Patents

Description

W. H. GRIFFITH. LIFTING JACK.

APPLICATION FILED OCT. 3, 1910.

1,052,913, Patented Feb. 11, 1913.

WILLIAM H. GRIFFITH, OF WORTI-IINGTON, INDIANA.

LIFTING-JACK.

Specification of Letters Patent.

Patented Feb. 11,1913.

Application filed October 3, 1910. Serial No. 585,084.

To all whom it may concern:

Be it known that I, WILLIAM H. GRIF- FITH, a citizen of the United States, residing at Worthington, in the county of Greene and State of Indiana, have invented certain new and useful Improvements in Lifting-Jacks, of which the following is a specification.

My invention relates to an improvement in lifting jacks, and the object is to provide means for releasing the lifting-head when it is desired to lower it upon the standard or bar.

The invention consists in certain novel features of construction and combinations of parts, which will be hereinafter described and pointed out in the claims.

In the accompanying drawings :Figure 1 is 'a view in side elevation, Fig. 2 is an enlarged sectional view through the liftinghead and runner, Fig. 3 is a top plan View of the catch, and Fig. at is a view in side elevation showing the catch in position when the lifting head is released from the standard or bar.

A, represents the standard or bar which is mounted upon the base B, and pivotally connected thereto by means of a bolt 1.

C, represents the lifting-head which is slidably mounted upon the standard A; and D, is the runner which is slidably mounted upon the standard A. A hand-lever 2 is pivotally connected to the head C at 30. An L-shaped lever 3 pivotally mounted in the runner C is pivotally connected to the hand lever 2 by means of a pin 4 which passes through an arc-shaped slot 5 in the head C. The other terminus of the L-shaped lever 3 is engaged by a. coil-spring 6, which spring engages the bar against the upper port-ion of the runner D, causing the lever 3 to rest against the lower side of the runner D. A recess 7 is formed in the runner D in which a gripping block 8 is received, which block engages the bar A for locking the runner to the bar when the head 0 is raised. A block 9 is provided with arms 10 which are pivotally connected to the lifting head C by a pin 11. An arm of the block is received on each side of the bar A, and a recess 12 is formed in the block carrying a toothed wedge or gripping block 13, which is adapted to engage the bar A. A socket let is formed in the head 0 in which is received a coil-spring 15, one end of which bears against the lower side of the block 9 for holding it in a raised position,

whereby the toothed wedge 13 will be caused to engage the bar A. When the lever 2 is moved to a horizontal position, the runner D will act as a fulcrum for causing the liftinghead or hook C to be raised upon the bar A, and when the lever is drawn to a vertical position, or its normal position, the runner D will move upwardly upon the bar. The teeth of the wedge 13 will have engaged bar A so as to hold the head C against any downward movement, thereby allowing the runner D to be drawn upward. When the head C is moved upward, the teeth of the wedge S will engage the bar, preventing the runner from moving upon the bar, and thereby acting as a fulcrum when the head G is raised or moved along the bar A. A notch 16 is formed in one side of the head C, in which is adapted to be received a latch 17, which is pivotally mounted upon the block 9, when it is desired to lower the head and runner upon the bar A. A projection 18 is formed upon the block 9 which can be engaged by the hand or foot of the operator for forcing the block down upon the spring 15, sufficiently far to allow the latch 17 to be thrown into the notch 16 for holding the block in a lowered position, thereby disengaging the wedge 13 from the bar A. Then by forcing the head C downward the head will engage the runner directly over the gripping block 8, causing the runner to be tilted, thereby releasing the gripping block 8, and allowing the runner and head to slide either in an upward or downward direction along the bar A.

A jaw 19 is mounted upon the standard A, and is held in position by thumb-screw 20. The jaw 19 acts as a handle when the device is used as a lifting jack. A toothed lever 22 is pivotally moimted upon the jaw 19, which acts in connection with a toothed projection 23 on the jaw for holding wire therebetween when the device is used as a wire stretcher. In stretching the wire, the wire is engaged between the toothed projection 24 of the head C and the toothed lever 25, which is pivotally mounted upon the head.

Having fully described my invention, what I claim as new and desire tosecure by Letters Patent, is

1. In a lifting jack, the combination with a bar, of a head slidably mounted thereon, a block pivotally mounted in the head, means normally holding the block in a position to engage the bar for holding the head in any of its adjusted positions, a projection carried by the block in position to be manually operated for releasing the block from engagement with the bar, and a latch connected with the block and engaging the head for holding the block in its released position.

2. In a lifting jack, the combination with a bar, of a head slidably mounted thereon, a block p-ivotally mounted in the head, a spring mounted in the head and bearing against the block for normally holding the block in a position to engage the bar, a projection carried by the block and extending through a cut away portion in the head in position to be manually operated for releasing the block from its engagement with the bar against the tension of the spring, a latch pivotally connected with the block on its upper side, and a notch in the cut away portion of the head with which the latch registers for holding the block in its released position.

In testimony whereof I affix my signature, in the presence of two witnesses.

WVILLIAM H. GRIFFITH.

Vitnesses CHAS. H. Born, A. B. GRIFFITH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). G.

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