US2555059A

US2555059A - Snatch block

Info

Publication number: US2555059A
Application number: US157321A
Authority: US
Inventors: Martin W Schrader
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-04-21
Filing date: 1950-04-21
Publication date: 1951-05-29
Anticipated expiration: 1968-05-29

Description

y 29, 1951 M. w. SCHRADER 2,555,059

SNATCH BLOCK Filed April 21, 1950 Maria); MJZb/var Patented May 29, 1951 UNITED STATES PATENT OFFICE SNATCH BLOCK Martin W. Schrader, Lafayette, La.

Application April 21, 1950, Serial No. 157,321

8 Claims.

This invention relates to a novel construction of pulley block, commonly known as a snatch block and which constitutes the device through which a cable is passed in order to lift or move heavy objects and which is extensively used in oil field operations, loading and unloading ships, in logging and mining operations and elsewhere where heavy loads have to be lifted or moved.

More particularly, it is a primary object of the present invention to provide a snatch block having a cable receiving pulley which is mounted in a block having a swingably mounted side capable of being readily swung to a released position to enable an intermediate portion of a cable to be applied to the pulley while the end portions of thecable are fastened, respectively, one to the load to be lifted or moved and the other to a winding drum or other apparatus for exerting a pull on the cable, thereby enabling the intermediate portion of the cable to be attached to or detached from the snatch block without removing any part of the snatch block to exposethe cable engaging pulley or without detaching any fastenings connecting the snatch block sections.

Still a further object of the invention is to provide a snatch block having a swingably mounted side provided with novel latch means for normally holding said side latched in a position for closing the sides of the pulley to prevent disengagement of a cable or other flexible element therefrom and which latched side may be readily unlatched and swung to a position for exposing one-half or side of the pulley by the use of one hand thereby leaving the other hand of the operator free to support himself on a derrick or other structure to which the snatch block is suspended.

Still a further object of the invention is to provide a snatch block of extremely simple con-' struction having a single journal for rotatably mounting the pulley and the swingably mounted snatch block side together with a novel latch structure which will automatically resume a latched position when the swingable mounted snatch block side is returned to its normal position for closing the upper half of the pulley or sheave.

Still a further object of the invention is to provide a snatch block which may be readily lubricated and maintained in a proper operating condition without disconnecting or removing any of the parts thereof. 7

Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the 1 2'5 to secure the hook H to the pin Ii.

2 drawing, illustrating a preferred embodiment thereof, and wherein:

Figure l is a front elevational View showing the snatch block in a closed position;

Figure 2 is a similar view, partly broken away, showing the snatch block in an open position;

Figure 3 is an edge elevational view thereof looking from right to left of Figure 1;

Figure 4 is a vertical sectional view taken substantially along a plane as indicated by the line l of Figure 3;

Figure 5 is a vertical sectional view taken substantially along a plane as indicated by the line 5-5 of Figure 1, and

Figure 6 is a cross sectional view taken substantially along a plane as indicated by the line t--6 of Figure 3.

Referring more specifically to the drawing, the snatch block in its entirety is designated generally B and includes broadly a block, designated generally 9, a pulley or sheave I 0 and a supporting hook II.

The block 9 includes a stationary side I2 which extends from top to bottom thereof, which has a stationary, preferably integral intermediate portion I3 which extends inwardly from the side I2 and which is provided with an integral upstanding part I I which is spaced from and corresponds to the upper end of the stationary or rear side I2. The upper end of the side I2 is provided with an opening I5 which aligns with a larger opening I6 in the block portion I4. A journal pin IT has a restricted end which is journaled in the opening I 5 and an opposite restricted end which is journaled in a bearing I8. The bearing is is secured by a press fit engagement in the opening I 6. The block 9 also includes a separate front side I9 which is spaced from the lower portion of the rear side I2 and which is supported by and swingably mounted on a journal pin '20, which likewise provides the journal for the pulley or sheave I0 and which will hereinafter be described in detail.

The pin H, which is turnably mounted in the upper end of the block 9 has a bore 2| ex- I tending diametrically therethrough. The snatch block supporting hook II has a depending shank 22 which is provided with a restricted terminal portion 23 which extends through the bore 2I and has a threaded end 24 which engages a nut The nut 25 is secured against removal from the threaded stem portion 24 as by welding, as seen at 26; A portion of the nut 25 may seat in a recess 21 of the pin I! to prevent the hook II from turn- 3 ing relatively to the block 9 on its longitudinal axis. However, said hook I I is free to swing relatively to the block 9 when the pin I'I oscillates in its journals and I8, between and beyond the dotted line positions of the hook shank 22 as illustrated in Figure 1.

The front side I9 of the block 9 is provided with an opening 28 which turnably engages a part of the. pin 20. and which is enlarged at the outer face of the side !9 to receive a portion 29 of the pin 26 by which the side I9 is retained on said pin. The pin 20 extends through an opening 30 in the lower part of the rear side I2 and a portion of said pin and the side 38 are recessed and threaded to receive a headed screw 3| by which the journal pin 22 is keyed to the rear wall I2. The terminal of the last mentioned end of the pin 20 is reduced in diameter and threaded as seen at 32 to receive a lock nut 33 which seats in a recess 34 of the outer face of the side I2. A bronze bushing 35 is disposed on the pin 25 and engages the bore of the pulley It so that said pulley or sheave is journaled directly on the bushing 35 for rotation between the block sides I2 and IS. A washer 36 is disposed between each side of the pulley it and the snatch block sides I2 and I9. The pin 29 is provided with lubricating passages 31 which open into the bushing 35 and into a recess 38 in the head of the pin 23 and which accommodates the head of a lubricating connection 39 which extends into the passage 3?! by which grease or other lubricant can be forced into the passage 37 and held against drainage back into the recess 33 by the fitting 39, which is of a conventional construction.

The intermediate block portion I3 is recessed on its front side as seen at 46 to accommodate the upper end of the swingably mounted front side I9 and is provided with an arcuate groove M which opens into the recess st and which extends from end-to-end of the part I3 and has an undercut or modified dovetail bottom portion. The free end of the side I9 has an inwardly extending hook-shaped extension #22 which is arcuately curved to conform to the groove AI and shaped to fit snugly therein, as best illustrated in Figures 3 and 5, so that the front side I9 may be swung on the pin 20 in either direction from its closed position of Figure 1 to disengage its free end from the block portion I3 to thereby expose the upper part of the pulley IE8 at the front side of the block 9, said front side I 3 being capable of swinging throughv an arc of 350 on the pin 29. The side I9 is provided with a longitudinally extending enlargement 43 adjacent its free end forming a finger rest by which said side may be swung toward or away from a closedposition.

The intermediate block portion I3 is provided with a bore i l having an enlarged end 55. which opens. outwardly from the rear face of the block 9 and a restricted opposite end 45 which opens into the groove M. A plunger 4-? isv reciprocally mounted in the bore M and has a restricted extension 48 which slidably and non-rotatably engages the restricted boreportion 56 and which isurged into the recess 4| by a spring E9 disposed in the bore 46 between the plunger 41 and a lubricating fitting 50 which threadedly engages the bore 44 and extends into its enlargement 45. The plunger i! is provided with a lubricating passage 55 which extends from end-to-end therethrough and by which a lubricant admitted to the bore d4 through the fitting 50 may pass into the groove 4I.

The upper, free end portion of the front side I9 has a bore extending therethrough and 4 I through its extension 42 and which includes an enlarged inner end 52 to receive the plunger end 48 which projects into the recess 49 for latching the swinging side is in its closed position of Figures 1, 3 and 5. Said bore includes a restricted intermediate portion 53 for slidably receiving the shank of a screw 54 having a head, a part of which is disposed in the recess 52, as seen at 55. A knob 56 threadedly engages .the opposite, outer restricted end of the screw 54 and is disposed in a flared outer end 51 of the bore 53 which, as seen in Figure 2 is formed partly in the front face of the intermediate portion I3 and which is substantially larger than the knob 56. The ends of the face of the extension (I2 are beveled on the side thereof which faces the inner wall of the arcuate groove 6!, as best seen in Figures 3 and 6, at 58 for a purpose which will hereinafter become apparent. The knob or button 55 may be displaced inwardly of the enlarged outer end portion 57 of the bore and which includes stepped portions extending inwardly to the restricted bore portion '53, to accommodate inward movement of said button 56 sufiiciently to displace the screw head 55 to the inner face of the extension 62 so that the head 55 will function to displace the plunger portion 48 out of engagement with the recess 52 when the button 56 is displaced inwardly to thereby unlatch the block side I9 from the latch plunger 4?, $8. The enlarged flared outer portion 5? affords ample space around the button or knob 56 so that a worker wearing gloves may readily displace the button or head 53 inwardly, as just previously described, with a gloved finger to thus unlatch the side I9 which is fr e to swing in either direction on the pin 29 when its recess 52 is thus disengaged from the plunger end 48 The front side I9 may be swung either clockwise or counterclockwise from its closed position of Figure 1 to an open position, as illustrated in Figure 2, so that an intermediate portion of a cable, not shown, may be inserted into the block 9 to engage the pulley It. The side I9 may then be returned to a closed position and latched by the plunger end 53 engaging the recess 52. As the free end of the side I9 is swung upwardly in either direction toward its. position of Figure 1 one end of its extension :32 will initially engage the arcuate groove. HI and as said end approaches a mid-way point of the groove 4| its beveled surface 53 will engage the end 43 of the plunger 4'! which is held projected into the groove ll by the spring 49 and will function as a cam surfacev for retracting the plunger 41, 6%, against the spring 49 from left to right of Figure 5 until the recess 52 aligns with the bore portion it. When the parts reach this point, the spring 49 will project the plunger 4? from right to left of Figures 5 and 6 so that the plunger end "68 will engage the head 55 of the screw 54 to displace said screw from right to left and to project the button 56 outwardly of the depression 51, so that the outer end. of the plunger portion 33 may seat in the recess 52 to latch the block side I9 to the stationary intermediate portion I3. The thumb or finger rest 43 may be utilized for swinging the side It to an open position after. the plunger 4?, 48. has. been retracted, as previously described.

It will thus be. seen that the. snatch block 8- provides a structure which may be readily opened for applying an intermediate portion of a cabie or other flexible element to its pulley or for r moving it therefrom and may be readily latched in a closed position to prevent accidental clisengagement of the cable or flexible element from the pulley. Likewise, the latch structure may be easily released with one finger and another finger of the same hand used to swing the pivoted side of the snatch block to an open position or for returning it to a closed and latched position.

The outer ends of the grease fittings and 5S correspond so that the same grease gun may be utilized for lubricating the bushing 35 and the latch structure in which the lubricating passage 5! is provided.

Various modifications and changes are contemplated and may obviously be resorted to, without departing from the spirit or scope of the invention as hereinafter defined by the appended claims.

I claim as my invention:

1. A snatch block comprising a block structure having a recessed upper end and a recessed lower end, a journal pin extending through and detach ably secured to the recessed lower end of the block structure, a pulley rotatably mounted on the journal pin in the lower recessed end or" the block, a pin extending through and journaled in the up per recessed end of the block, a snatch block supporting hook having a shank end secured to the last mentioned pin and swingably supported thereby for swinging movement relatively to the block and pulley, said block having a separate portion defining one side of its lower recessed end, said side constituting a plate swingably mounted on the journal pin of the pulley adjacent one end thereof for exposing the upper part of the pulley in one position of said plate and for closingsaid side of the upper portion of the pulley in another position of the plate, said block including an intermediate portion having a front face recessed to accommodate the free end of the plate when in said last mentioned position, the free end of said plate being provided on its inner side with an extension of a modified dovetail cross section which is arcuately bowed from end-to-end there of, said intermediate block portion having a groove opening into the recessed front face in which said plate extension is slidably received and snugly engaged when the plate is swung upwardly for closing the pulley side, and latch means mounted in said intermediate block portion and releasably latching the plate with its free end in engagement with the intermediate block portion.

2. A snatch block as in claim 1, and means for detachably securing and keying the pulley journal pin to the other, stationary side of the pulley block.

3. A snatch block as in claim 1, a bushing mounted on the journal pin between said pin and the pulley, washers mounted on said pin between the sides of the pulley and the sides of the block structure, and means for lubricating said bushing, pin and pulley through one end of said journal pin.

4. A snatch block as in claim 1, said latch means comprisin a spring pressed plunger hav ing a portion which is normally spring biased into the arcuate groove of the intermediate block portion which receives the plate extension, and said plate extension having a recess intermediate of its ends for receiving said plunger end to releasably latch the free end of the plate in engagement with the intermediate block portion.

5. A snatch block as in claim 1, said latch means comprising a spring pressed plunger having a portion which is normally sprin biased into the arcuate groove of the intermediate block lit) portion which receives the plate extension, and said plate extension having a recess intermediate of its ends for receiving said plunger end to releasably latch the free end of the plate in engagement with the intermediate block portion, a latch operator reciprocally mounted in the plate and plate extension, the spring pressed plunger urging the latch operator to a retracted position when the recess of the plate extension is disposed to receive the plunger, said latch operator having an exposed end forming a button located at the front face of the plate and adapted to be manually engaged for displacing the latch operato inwardly to retract the latch plunger out of engagement with the recess of the plate extension.

6. A snatch block as in claim 1, said latch means comprising a spring pressed plunger having a portion which is normally spring biased into the arcuate groove of the intermediate block portion which receives the plate extension, said plate extension having a recess intermediate of its ends for receiving said plunger end to releasably latch the free end of the plate in engagement with the intermediate block portion, and means for lubricating the latch plunger and plate extension through the intermediate block portion and through said latch plunger.

'7. A snatch block as in claim 1, said latch means comprisin a spring pressed plunger having a portion which is normally spring biased into the arcuate groove of the intermediate block portion which receives the plate extension, and said plate extension having a recess intermediate of its ends for receiving said plunger end to releasably latch the free end of the plate in engagement with the intermediate block portion, a latch operator reciprocally mounted in the plate and plate extension, the spring pressed plunger urging the latch operator to a retracted position when the recess of the plate extension is disposed to receive the plunger, said latch operator having an exposed end forming a button located at the front face of the plate and adapted to be manually engaged for displacing the latch operator inwardly to retract the latch plunger out of engagement with the recess of the plate extension, said plate recess being flared at the outer surface of the plate and around the button.

8. A snatch block as in claim 1, said latch means comprising a spring pressed plunger having a portion which is normally spring biased into the arcuate groove of the intermediate block portion which receives the plate extension, and said plate extension having a recess intermediate of its ends for receiving said plunger end to releasably latch the free end of the plate in engagement with the intermediate block portion, a latch operator reciprocally mounted in the plate and plate extension, the spring pressed plunger urging the latch operator to a retracted position when the recess of the plate extension is disposed to receive the plunger, said latch operator having an exposed end forming a button located at the front face of the plate and adapted to be manually engaged for displacing the latch operator inwardly to retract the latch plunger out of engagement with the recess of the plate extension, said latch operator being formed of detachably connected end sections one of which comprises the button, said sections being removably applied to the plate recess from opposite sides of the plate.

MARTIN W. SCI-IRADER.

No references cited.