US2296569A - Quick-opening snatch block - Google Patents

Description

Sept. 22, 1942- J. PETERSON QUICK-OPENING SNATCII BLOCK Filed Aug. 15, 1.941 I 2 Sheets-Sheet 1 Sept. 22, 1942. J. PETERSON 2,296,569 QUICK-OPENING 'szm'cn BLOCK Filed Aug. 15, 1941 z'sneets-sneeg 2 Patented Sept. 22, 1942 UNITED STATES PATENT OFFICE 1 Claim.

My invention relates to quick-opening snatch blocks of the kind used by lumbermen, telegraph and telephone linemen, dock workers, and in various places where it is frequently necessary to disengage the block from its co-operating cable, and its principal object is to provide a block of the character specified in which removal and insertion of the cable may be quickly and easily effected.

My said invention is more particularly applicable to a quick-opening snatch block of the type described and shown in my prior Patent No. 1,908,784, issued May 16, 1933, and it comprises improvements by which the parts are more securely locked in position at all times when the block is in use, thereby eliminating the possibility of accidents due to the opening of the block while under load. The improved locking means is so constructed that the parts are less liable to jamming through the action of dirt, and also better protected from damage due to impact on various external bodies, which frequently occurs during operating under the rough conditions which obtain in places where such blocks are employed.

With these and other objects in view, a preferred embodiment of my said invention will now be described with reference to the accompanying drawings, in which the same characters as those employed in the prior patent, aforesaid, are used to designate the principal parts of the block. In these drawings- Figure 1 is a fragmentary side elevation showing the hanger I and other related parts.

Figure 2 is a section taken on line 2-2 of Figure 1 showing the means for locking the trunnion of the hoist block in place.

Figure 3 is a fragmentary section taken on line 3-3 of Figure 2, but showing the hanger disengaged from the trunnion of the hoist block, thus allowing the removal of the hook and other parts necessary to detach the hoist rope from the block.

Figure 4 is a section taken on line 4-4 of Figure 2.

Figure 5 is a fragmentary side elevation corresponding to Figure 1, but showing a modified form of locking device.

Figure 6 is a section taken on line 66 of Figure 5.

Figure '7 is a fragmentary section taken on line l'| of Figure 6, but showing the hanger l0 disengaged from the trunnion of the hoist block, thus allowing the removal of the hook and other parts necessary to detach the hoist rope from the block, and

Figure 8 is a section taken on line 88 of Figure 6.

Figure 9 is a vertical section drawn to an enlarged scale showing the complete block with the locking device of Figures 5, 6, '7, and 8 applied thereto.

Like characters designate corresponding parts throughout the several views.

Referring more particularly to Figures 1 to 4 of the drawings, I is a side plate or cheek, of which there are two disposed at equal distances from the center line of the block, the sheave 5 being rotatably supported upon an axle passing through these cheeks, and below the center of the sheave 5 is the hook it, the shank of which is rotatably carried within an opening in the crosshead IS, the said crosshead having a pair of trunnions, one of which is shown and designated l3. In order to support the crosshead from the block, there are secured to the upper portions of the cheeks I a pair of flat members 8 which terminate at their lower ends in loops, the left hand of which is designated 9, and from these loops are suspended as by the integral cross members l2 a pair of hangers, the left hand of which is designated ID in the drawings, the latter having an opening N12 to receive the trunnion 13 upon the crosshead. On the other side of the block is a similar hanger, not shown, to which the right hand trunnion of the crosshead is permanently secured as by a nut or collar, the arrangement being such that by swinging the hanger Ill into the position shown at l0l in Figure 3 of the drawings, disengaging it from the trunnion 13, the companion hanger may be swung outwards in the opposite direction, carrying with it the crosshead and the hook. When the hangers are thus opened up, it is possible to remove the rope from the sheave and to reinsert it as desired. Upon the hanger l0, intermediate the crosshead and the sheave, is a frusto-conical projection 29 and the companion hanger has a similar projection, so that between the two is supported rotatably the guide roller 30 which serves to keep the cable within the groove of the sheave 5. When the hangers are spread apart as above described, this guide roller can be easily removed so as to facilitate the work of changing the rope.

In order to lock the hanger It) in position, there is secured to the outer face of the said hanger, as by the screws 4|, a hollow member 40. Within the cavity 42 of this member are a pair of levers 43, 44 supported at their lower ends by a pivot pin 45, these members being of arcuate form, as at 46, 41, near the pivot pin, so that when they are in the locked position, as shown in Figure 2 of the drawings, the arcuate portions engage a groove 18 in the trunnion 13. The levers 43 and 44 are held in their locking position as by helical springs 48 which are backed up by screw plugs 49. Pivoted at 50 to the member 40 is a lever 5|, the lower part of which is located intermediate the members 43, 44, as shown in Figure 2, and its upper part terminates in a handle-like member 52. Thus, by pressing the handle in the direction of the arrow :1: in Figure 2, the member 5| impinges upon the levers 43, 44 so as to open them up and disengage the trunnion l3. In order to protect the mechanism just described from dirt and water, there is provided an arcuate cover 53 from which the handle 52 projects, the said cover sliding in grooves 54 in the member 40. The outer end of the trunnion I3 is rounded, as indicated at l3| in Figure 3, so that when the parts are in the relative positions shown in Figure 3 and the hanger I is swung inwardly, the locking members 43, 44 will automatically slip into the groove H3 in the trunnion. Conversely, when it is desired to disengage the trunnion, manual pressure on the handle 52 opens up the levers 43, 44, disengaging them from the groove l8 and allowing the hanger Hl to be swung into the open position, as shown in Figure 3.

In Figures to 8, inclusive, is shown a modifie'd form of the means for locking the hanger H1 in position upon the block. In Figure 9, I and 2 are the side plates or cheeks, substantially circular in elevation, connected together at their upper ends by'bolt 3 and at their center by the bolt 4. The bolt 4 serves as an axle for the sheave 5 which is normally held in a bight of the cable 6. Secured to the cheeks I, 2 by the bolt 3 and the central bolt 4 are the loops 8 formed of flat bars and bent to form at their lower ends eyes 9 through which pass the cylindrical horizontal portions I 2 of the hangers l0 and II, which are thereby suspended from the said loops and are bored at their lower extremities to receive the trunnions l3, l4 of the crosshead I5, the latter having a central opening to receive the shank of the hook it in the manner well known in the art. In this arrangement there is secured to the outer face of the said hanger, as by the screws 6|, a hollow member 65. Within the cavity 62 of this member is a slide 63, preferably formed from r spring steel and having at its lower end a circular opening 54 sufiiciently large to receive the trunnion l3 of the block, and below this is an arcuate opening 65 which is of substantially the same radius as that of the bottom of the grove l8, so

that by moving the slide upwards, from the position in which it is shown in Figure 6, until the said arcuate portion fits against the bottom of the groove, the trunnion is locked in place. The lower portion of the slide has flat faces 66 which are guided between parallel faces 6'! in the member 60, and the upper part of the slide has fiat members 10 which slide in grooves H in the member 60, the said members having on their outside faces serrated portions 12, as shown in Figure 5. Intermediate the portions 53 and 10 of the slide are a pair of arcuate spring portions 13 which are under such compression that they tend to spread outwards, and in these spring portions are notches 14 adapted to engage pins 15 in the member 60. As shown in Figure 6, the spring portions are compressed and disengaged from the pins, but when the slide is raised upwards by means of the members 10, the notches 14 engage the pins I5 so as to lock the slide in the upper position. Adjacent the members 12 are bevelled openings 16 in the members 60, whereby the fingers of the operator have access to the members 10 It will be observed from the foregoing description and by reference to the drawings that I have provided locking means which are capable of withstanding a large amount of abuse such as is inseparable from the work in which these blocks are employed, and while I have herein described and shown preferred embodiments of my said invention, it will be readily understood by those skilled in the art to which the same pertains that various modifications in detail may be made to suit any particular or peculiar requirements without departing from the spirit of my, invention as defined in the appended claim.

Having thus described my said invention, what I claim and desire to secure by Letters Patent of the United States is:

The combination with a flexible hoisting element, of a block comprising a pair of spaced complementary side members; an axle supported in said side members; a sheave mounted on said axle and engaging in a bight of said hoisting element; load-engaging means including a crosshead having a pair of opposed trunnions; and a pair of suspensory members hinged to said side members and adapted to engage said trunnions, one of said trunnions being permanently connected to its associated suspensory member while the other trunnion is detachable therefrom; of means for securing said detachable trunnion in position in its co-acting side member, said means comprising a groove in said trunnion, a slide mounted upon said side member having a circular opening adapted to pass over said trunnion and an arcuate opening adapted to engage said groove, a pair of spaced projections upon said member, a pair of arms upon said slide adapted to engage said projections and to maintain the slide in engaged position, and manual means for disengaging said arms to release the slide.

JOSEPH PETERSON.

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