US1620525A - Power hammer - Google Patents

Description

March 8,1927. v 1,620,525

. F. H. DERBY POWER HAMMER Filed Oct. 26. 1922 2 Sheets-Sheet 1 F. H. DERBY M arch 1927. 1,620,525

POWER HAMMER Filed Oct. 26. 1922 2 sheets-sheet 2 4 E llllllwmgi n 40 Patented Mar. 8, 1927.

' U N D AT ES 1,620,525 PATENT v orrrca.

FRANK H. DERBY, OIE ERIE, PENNSYLVANIA, ASSIGNOR TO ERIE FOUNDRY GQMPANY, OF ERIE, PENNSYLVANIA, A OORPORATIQN F PENNSYLVANIA.

POWER HAMMER.

This invention is designed to improve power hammers, particularly power hammers in which there is a lifting device automatically thrown into and out of engagement by the action of the hammer; With devices'as commonly used the hammer delivers a uniform blow and the return or lifting stroke is brought about with the same relative timing. In order to vary the action of the hammer and particularly to obtain the benefit of the rebound in pickingup the hammerhead to retract it, it is desirable to have the means for throwing into engagement the lifting mechanism so adjustable that the timing may be varied to suit the conditions under which the hammer is used and to have this means adjustable while the hammer is actually in operation. WVith the present invention this is accomplished. Features of the invention will appear from the specification and claims.

The invention is illustrated in the accom-- panying drawings as follows Fig. 1 shows a front elevation of the hamnier.

Fig. 2 a section on the line 2-2 in Fig. 1.

Fig. 3 an enlarged section on the line 33 in Fig. 1.

Fig. l an enlarged front elevation of the tripping mechanism.

1 marks the base, 2 the anvil, 3 the side 4 frames, 4.- the hammer guides, 5 the hammer head, and 6 friction lifting bars preferably of wood. The lifting bars extend upwardly between the friction pulleys 7 and 8, these pulleys being mounted on shafts 9 and 10 driven by pulleys 11 and 12. The shaft 9 is journaled in a bearing 13 and the shaft 10 in a bearing 14. These bearings are carried on posts 15 on a cap plate 16. The bearing 14 is arranged in an eccentric 17 Lever arms 18 extend from the eccentric and a trip rod 19 is pivotally connected with the lever arms 18. So far the structure is one commonly used. As the ee centric 17 is operated the friction pulleys 7 and 8 are thrown into and out of frictional engagement with the bars 6 so as to alternately lift the hammer and drop it.

The releasing trip mechanism is as follows: A lever 20 is pivotally mounted on the rod 19 by means of a pin 21. The lever is provided with a socket 22 which engages a pin 23 on the frame. The inner end of a recess 37 in the latch block.

Application filed October 26, 1922. Serial 110.5%,087.

the leveris in the path of the pin 2% on the hammer head. As the hammer reaches its upper position the pin 2& engages the lever, lifts the rod 19 and this swings the eccentric 17' soas to disengage the pulleys"? and 8, thus tripping the hammer.

The lower end of the rod 19 extends through a guide 25 secured to the frameand as the rod 19 is lifted the ratchet shoulder 26 is caught by thelatch block 28 and thus holds the rodin the upper position until the hammer reaches the lower position and actuates the latch. The shoulder is the form of aslottedblock and is clamped by screws 27 on the rod 19. The block 28 slides in a guide 29 on the frame and is held in the guide by a plate 30 secured to the frame. The latch block is forced forward by a spring 31. A latch bar 32 extends forwardly from the latch block and has a cam or bevelled end 33 which extends into the path of a cam 3% on the hammer head so that as the hammer descends the cam operating on the latch bar forces the latch block outwardly and thus releases the latch shoulder 26 and allows the rod 19 to drop so as to throw the pulleys 7 and 8 into engagement. The latch bar 32 is secured on the frame by means of the guiding plate 35 which is secured to the frame. The latch bar has an ear 36 at its outer end which extends into A screw 38 extends through the ear and is provided with collars 39 at each side of the ear 36 so that the screw is free to rotate in the ear but is locked against axial movement rela tively thereto. The screw extends into the latch block so that as the screw is turned in and out of the latch block it carries the latch block 28 inwardly, or outwardly, and thus varies the time that the latch block 28 is moved from under the block 26 and the time in which the retracting movement of the mechanism starts. The screw has a shoulder dO which engages the outer face of the bushing l0 and the bushing is locked in place on the frame by a cover plate 41. This shoulder forms a positioning stop, therefore, for the latch block the spring 31 forcing the screw forward until stopped and positioned by the shoulder -10. When the cam 33 is engaged and forced to the rear the car 36 operating on the shoulder 39 forces the screw outwardly, the screw returning under the influence of the spring to the position with the stop against the bushing 40. The outer end of the screw has a perforated projection 42 by means of which the screw may be turned so as to adjust the latch bar.

It will be noted that the latch bar may be adjusted during the active operation of the hammer so that the operator may adjust the hammer so as to have it delicately respond to the conditions required.

A hand-operated lever 43 is pivoted at it and is adapted to lift the rod 19 in starting the hammer.

What I claim as new is 1. In a power hammer, the combination of a hammer head; a power-actuated lift device for the head; means throwing said device into and out of lifting relation with the head; a latch shoulder on the means; a latch comprising a sliding cam bar having one end in the path of the head; an adjusting screw;

a connection between the screw and bar maintaining a fixed axial relation between the bar and screw; a latch block on the screw in overlapping latching relation with said shoulder and adjustable relatively thereto by the screw to vary the timing of the means; and a stop maintaining a constant relation between the bar and head as the block is adjusted by the screw 2. In a power hammer, the combination of a hammer head; a power-actuated lift device for the head; means throwing said device into and out of lifting relation with the head comprising a trip rod; a shoulder on the trip rod; a sliding cam bar having one end in the path of the head; a shoulder on the cam bar; a screw extending through the shoulder; stops on the screw locking the shoulder with the screw; a latch block arranged on the screw and adjustable thereby and co-operating with the shoulder on the trip rod; a stop for the screw; and a coil spring around the screw forcing the block and cam bar to their forward position.

In testimony whereof I have hereunto set my hand.

FRANK H. DERBY.

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