US2827807A

US2827807A - Attachment for drill

Info

Publication number: US2827807A
Application number: US641546A
Authority: US
Inventors: Lester L Meyer
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-02-21
Filing date: 1957-02-21
Publication date: 1958-03-25
Anticipated expiration: 1975-03-25

Description

March-25, 1958 L. L. MEYER 2,827,807

ATTACHMENT FOR DR ILL Filed Feb. 21, 1957 JIE, 3

INVENTOR. L ES 7'51? L, MEYER 28 I 35 HIS flTTO A/FYS United States Patent F "ATTACHMENT FOR" DRILL Lester L.- Meyer,- Arcanum, "Ohio 'Application February 21,1957, SeriaPNo'i 641,546

' 7.-Claims. ((1177-14) 'This invention relates toanatttichmen't forelectric hand drills, the -attachment being adaptd'for usetin drawing a "work to 'be' drilledtoward the drill; although the adaptation of'the attachmentis' not necessarily'limited '16 hand drills.

An "object of'this' invention'is to providetan attachment for an electric hand drill which serves;first;as a'h'andle for supporting the drill; and; second; asia housing for an "assembly 'for'en'gaging the work to be drilled and to! drawing the work toward 'the drill; which asser'riblyana; be actuated 'manually by an' operator; 'with'the same hand used-to'support the drilL'to draw the work in a stepwise manner toward the drill.

Another object of this invention is to provide an attachmentfor a drill for drawing a'work to be drilled "toward the drill; whereinthe attachment includes means'for'yieldably drawing'thework towardthe drill and 'm'anuallypp- "erahle ratchet and pawl means for positively drawing the Worktowardthe drill in a'stepwise manner. ,1" "Still another object of this invention'is 'topr'ovide' an attachment for a drill for'drawing a work to be' drilled 'towardthe drill including a cable adapted'to'support the work and ratchet and pawl means for actuating" the cable, "wherein the ratchet'means'to which'the cable is secured is rotatably mounted so as to be rotatable with the cable.

Other objects and advantages reside 'inthe construction elf-parts; the combination thereof, themethod' of'm'anufacture and the mode of operation; as will becomem'ore apparent from the following description.

In the drawing Figure 1 is a perspective view of an electric hariddiill illustrating the attachment which is the subject ofthis in- 'vention.

Figure 2 is an elevational view with-'portions shownin section, illustrating the construction ofthe attachment and showing, in solid and broken lines, 'two' positions -of a ratchet actuating assembly associated with the attachment.

Figure 3-is an elevational view, with'portionsshown in section, illustrating a third position of the ratchet actuating assembly.

Referring to the drawing in detail, Figure l'illustr'ates a conventional-pistol grip type electric hand drilI to which the attachment 12, which is the subject ofthis-Iinvention, is attached. The attachment '12 comprisesa tubular handle portion 14, an actuating lever.16, and a cable18,-which;:as=will'be described later; may be selecv tively drawn into and released from the -handle portior'il4. The. cable 18 is provided at one .end with a =hook-- 20 adapted to engage a chain 21, or the like, looped around or otherwise. secured .to the work 22'to be drilled. For the purposes. of illustrationsonly the work 22 is a wooden board or a metallic bar.

As" illustrated ,in Figure 2, the tubular handleyportion "14 is provided atone end with an externally'threaded portion' 24 for attachment to the hand'drill 10, and is pro- 'vided at the other end with anintern'ally threaded portion 26 adapted-to receive aplug 28.

The handle portion is" threadedly secured to the drill 2,827,867 Patented Mar. 25,1958

' housing so as to extend substantially normal to'the rota- 0 which extends-"almosttheentire length-thereof. I Atcoil ;spring 34 extending within the boring 33is anchored at the inner eiid offthe'boring -33ito the ra'tchet-ba1= 30 by a pin or 'rivet '36 which is welded, press-fitted, or otherwise secured in place. .Thelspring34 is anchored -atthe other end thereofttoT-theplug '28by a suitable pin -or rivet 38. The construction of the vspring 34 is such that whenthe ratchet bar 30 rests uponlthe plug -28,the spring is under Aaslight tension. As'the ratchet,bar 30 isppulled away lfrom l the Plugj'ZSjthtehsion of thetspring increases; tendling to draw the ratchet bar back toward the plug =28. The 4 c'abl'18, secured to theend'of the ratchetbar- 30 opposite the spring 34, extends from-the ratchet bar 30 out of'the a-handle portion 14 through an iopeningintthe wall" thereof adjacent'thethreaded portion 24 at the .end of thehandle portion-14. 5 Th-length of .the cable 18-is approximately .halfI'thet-leng-th 'ofthe handle portionv 14.

f'The cable 18; in passing out ofsthe handle portion 14, passes over a; 'eue' 40 journalledupon ashaft- 42. sup- I ported: between spaced brackets onfplates 44 weldedto opposite, .sidesu'of -the handle 3 portion l4-adjacent the threaded portion 24. These parallel plates '44 are recessed partiallyinto a the peripheral w all ofathe tubular handle portion 14. The actuating lever: 16 is also'pivotally selcured totheplates 44 upona shaft 48. -This -le-ver-is adapted to be pivoted between a position parallel-10 and adjacent the handle portion. 14, asishownd'n broken line -detail in Figure ,2, and positions antiparallel to the handle 9 portion 14, one bf which :isflshown in solidvline detail in (Figure 2. "Y he lever 16 is rounded on the surface-facing away fromfthe handle porti0n'=14, such that an: operator may-conveniently grip SimutaneOuSIy-thehandie portion a 14 and lever 16.

"Pivotally securd tothe lever16 =uponashaft-5tl=isa pawl '52. The; pawl 52: is adapted'to-project QHHQ the 45 handle. portions v14 through an opening-provided therefor .ini'the wall of the handle; portion l iinto-engagement with [the "ratchet. bar 30. The; pawl 52 when engaging the ratchet bar'30 opposes movement of the ratchet'bar 530 in-. opposition -to thespring'34. Thepawl-SZ-is-pro- 5o vided with-a bifurcated arm. portion 54 engaging the lshaft'lsib. The bifurcated arm portion I 54: straddles a hairpin spring element 56, one legof which :is nestled within the lever 16 and theother legof-whicht-bears against the pawli52-,-iso as to-urge the pawl-52 intotantiparallel relationship to the lever 16. In toperatiom-the springSG tends to urge-the pawl 52 into engagement with the ratchet bar30 and simultaneouslywtends-to bias the lever 16 antiparallel to the handle portion 14. A second 'pawl'58ispivotally secured to a U-shaped bracket memb'er 6.0 welded to thethandle portionll tiintspaced relation "to'the pawl- 52 A leat spring member 52f-fixedly seic'ured to the"'bracket member 'fianrges the awrss into engagemenf'w'ith the ratchet 'bar '30. a The construction I of the"pawl"'58,"'like 'thattof the pawli52, is such as to 5 resist movement 'of the ratchet bar30 in opposition to the spring34. I V V It is"to'ibe noted 'thatthe'fshaft 50, supporting the pawl -52; is spaced: from'the shaft 48,isupporting the lever 16, such thatljas'the lever 16"isjpivoted'trom1the solid line position shown' inhigure' 2 tosubstantial parallel relation with the handle portion 14,"'as 'shown'ia'br'oken hne in Figure 2,"-'the pawl 52' is' caused "to "rnoveairially so as to drive the ratchet bar 30 asazsort-t V V 14 toward the plug 28. The arrangement is such that the' axial movement of the pawl 52, as the lever 16 is moved manually into parallel relation with the handle portion 7 14, exceeds the spacing between notched portions 32 on the ratchet bar 30. As the ratchet bar 30 is driven axially by the pawl 52, the pawl 58 is caused to jump a notch on the ratchet bar and then to l e-engage the ratchet bar a 30. On subsequent release of the lever 16, which under the actionof the spring 56 is pivoted outwardly from the handle portion 14, the pawl 52 jumpsta notch on the ratchet bar 30.

Clearly, by repeated manual actuation and release of A the lever 16, the ratchet bar 30 may be driven axially in the handletportion 14 toward the plug 28, thus drawing the cable 18 over the pulley 40'into the handle portion 14.

The cable 18 may be subsequently withdrawn from the .7

' ure 2 such that the arcuate, surface 66 of the pawl 52 engages and pushes against the tongue 64 of the pawl 58 and simultaneously the arcuate surface 68 of the pawl 52 engages the lip 70 associated with the handle portion 14. Clearly,

thesprings

56 and 62 are in opposition when the lever 16 is in this position. Due to the low mechanical advantage associated with the spring 56 in this position, however,;the spring 62 prevails and urges the pawl 58 into positive engagement with the ratchet bar 30.

By manually urging the lever 16 away from the handle portion 14 to the position shown in Figure 3, the arcuate surface 68 of the pawl 52 may be caused to camupon the lip 70 of the handle portion 14 against the tongue 64 of the pawl 58, so as to move the pawl 58 out of engagement with the ratchet bar 30 in opposition to the spring 62. By such movement of the lever 16, both

pawls

52 and 58 may be caused to simultaneously disengage the a ratchet bar 30. Outward movement of the lever 16 from the handle portion 14 is limited by an abutment 72 associated with the plates 44 which engages a complementary abutment 74 associatedtwith the lever 16.

When-the lever 16 is manually pivoted to this extreme antiparallel position, the cable 18 may be manually withdrawn from the handle portion 14 by grasping the hook 20 attached to the cable18 and'pulling the cable 18 in opposition to the spring 34. When the cable 18 has been withdrawn, the handle portion of the lever 16 may -'be returned to the intermediatenon-parallel position,

shown in Figure 2 in solid line'detail, whereupon the pawl 58 'will engage the ratchet bar 30. v V

The operation of the device is as follows: After actuating the lever 16 to its extreme antiparallel position with respect to the handle portion 14, as shown in Figure 3,

the cable 18 may be manually withdrawn from the handle portion 14, whereupon the hook 20 may be attached to a chain or the like for supporting the work to be drilled. The spring 34, opposing withdrawal of the cable, 18 from the handle portion 14, operates to draw the cable 18 back into the handle portion 14 to take up slack in the cable 18 and work engaging chain. Subsequently, the lever '16 is returned to the intermediate,antiparallelposition,

shown in solidline detail in Figure 2, and thedrill is put into operation. peatedly, while simultaneously supporting the drill'by the handle portion 14, the ratchet bar 30 may be driven axially in the handle portion 14 so as to cause the drill to pene- 58 serves to trate the work. In this operation, the pawl prevent slippage of theratchet bar'30.

So that the lever 16 maybeproperlyoriented 'on the By manually actuating the lever Hire-- axially in the handle portion handle portion 14 for convenient actuation while the drill is being operated, the end of the handle portion engaging the drill housing is provided with internal threads at 49 for receipt of a tapered plug 51. The depth of the plug 51 in the handle portion 14 is adjusted such that when the handle portion 14 is turned tightly into place in the drill housing, the handle portion 14 has the proper angular orientation relative to the drill housing. To facilitate adjustment and locking of the plug 51,-the handle portion 14 is split at 53.

It is to be noted that the ratchet bar 30 which is rotable in the handle portion 14 is capable of rotating'with the cable 18. Thus, while the cable 18 may ordinarily tend to twist during the drilling operation and thus besubjected to harmful torsional stress, such a result is precluded in the present invention.

Although the preferred embodiment of the device has been described, it will be understood that within the pur- 7 view of this invention various changes may be made in the form, details, proportion and arrangement of parts, the combination thereof .and mode of operation, which generally stated consist in'a device capable of carrying out the objects set forth, as disclosed'and defined in the appended claims.

7 Having thus described my invention, I claim: 7 1. An attachment for an electric hand drill including .a tubular handle portion attachable at one end to the drill housing and adapted for use in holding the hand drill, a ratchet bar mounted for reciprocal axial movement in said handle portion, said handle portion having an open- 7 ing in the wall thereof, a cable having one end secured to said ratchet bar passing through said opening and having the other end thereof adapted to support a work to be drilled, a lever pivotally secured to said handle portion, the construction and arrangement being such that said lever may be actuated manually by an operator with the ,same hand used to hold the handle portion, and pawl means responsive to pivotal movement of said lever for actuating said ratchet bar axially in said handle portion in a stepwise manner so as to-draw said cable into said handle portion thereby drawing said work towards the 'drill.

2. The attachment according to claim 1, wherein said ratchet bar comprises a substantially cylindrical member provided with axially spaced annular notched portions adapted to be engaged by said pawl means, and wherein,

said ratchet bar is mounted for rotation in said handle portion.

- 3. The attachment according to claim 1, including spring means biasing said ratchet bar axially in said' handle portion so as to exert a spring tension tending -to draw said cable'into said handle portion.

4. An attachment for an electric hand drill including i a tubular handle portion attachable at one'end to the drill housing and adaptedto extend substantially normal to the axis of rotation of the drill, a ratchet bar mounted for reciprocal movement in said handle portion, said handle portion having 'an opening in the wall thereof, pulley means secured to said handle portion adjacent the .opening therein, a cable having one end thereof secured 'to said ratchet bar passing out of the opening in said handle portion over the pulley means, said cable being adapted at the other end thereof to support a Work to be drilled, a lever pivotally secured to said handle. portion and having a first position substantially parallel to said handle portion, spring means biasing said lever into a t second position antiparallel to said handle portion, the

construction and arrangement being such that an operator grasping said handle portion to hold said drill may,

with the sarne h'and', actuate said lever repeatedly from i said second position to said first position, and pawl means :responsive to movement of said lever for actuating said ratchet bar axially in said handle portion in a stepwise manner so as to draw said cable into said handle portion thereby drawing the work supported by said cable towards said drill.

5. The attachment according to claim 4, wherein said lever has a third position in extreme antiparallel relation to said handle portion, and including cam means responsive to movement of said lever to said third position for disengaging said pawl means from said ratchet bar, and spring means urging said ratchet bar axially in said handle portion so as to draw said cable into said handle portion when said pawl means is disengaged from said ratchet bar.

6. The attachment according to claim 4, wherein said ratchet bar comprises a substantially cylindrical member provided with axially spaced annular notched portions adapted to be engaged by said pawl means, and wherein said ratchet bar is mounted for rotation in said handle portion.

7. The attachment according to claim 4, wherein the end of the handle portion attachable to the drill housing is provided with an externally threaded portion for threadedly engaging the housing and an internally threaded portion, and including a tapered plug threadedly engaging said internally threaded portion so as to adjustably engage said handle portion, the construction and arrangement being such that said piug may be adjusted to enable positioning of'said handle portion in a predetermined angular relation to said housing, said handle portion having a split portion in the end thereof receiving said plug providing a spring tension for locking said plug in position.

References Cited in the file of this patent UNITED STATES PATENTS 2,097,949 Johnson Sept. 1, 1936 2,695,525 Butenhoff Mar. 3, 1950