US2803286A

US2803286A - Tool for setting tabs by twisting same

Info

Publication number: US2803286A
Application number: US512048A
Authority: US
Inventors: John R Bos; Robert B Shulters
Original assignee: Gardner Denver Inc
Current assignee: Gardner Denver Inc
Priority date: 1955-05-31
Filing date: 1955-05-31
Publication date: 1957-08-20
Anticipated expiration: 1974-08-20

Description

Ag. 20,11957 J. R. Bos ET Al. 2,803,286

Tool. Row SETTING TABS BY TwIsTTNG SAME Filed May 31. 1955 2 sheets-sheet 1 /y mi I/559 w 5o 68"' |3 Qui I, 52 l ,/'O 65V,r n 1 @T TTT-. A 5.

1 i T T si #le l?! l fik' i "a L? A5 24 "fg H 7| S9 INVENToRs 7o John A2 50s y\ ober 5. Shu/ters '0 @YW/@ A TTC/PNE Y Aug. 20, 1957 J. R. Bos ETAT.

Toor. FOR SETTING TABS By TwIsTTNG SAME:

2 Sheets-Sheet 2 Filed May 31,' 1955 INVENTORS' ./o/m Q 50s Pobe/fz 5, Shu/fers ay @al mwmm A frate/ve Y United States lPatent O 'TOOL FOR SETTING TABS 'BY TWISTING YSAME John R. Bos, Grand Haven, and Robert B. Shulters,

Spring Lake, Mich.,-assignorstoGardner-Denver Company, Quincy, lll., a corporationof .Delaware Application May 31, v1955, lSerial No. `512,048

4`Claims. .(Cl. 153-178) :this .invention is concerned `with ia-`tool designed 1to 'twist for set these tabs automatically.

The use of metal tabs on small components for'thepurpose .ofattaching vthem "to vtheir supporting structure has ibeenfound Afar more satisfactory than the Vuse of conventional l,fasteners .such 4as screws, bolts or rivets. `Such tabs vprovide a tight, vibration proof means of attachment. They .eliminate 'the necessityof handling and assembling additional ,small parts :such 'as screws or rivets and the attachment of the components by this `means is substanltially more rapid than `by `any 'other means.

The benets obtainable from the :utiliza-tion of twisted -Itabs vrather ,than conventional .fasteners lis lin no 7small part dependent upon the `eilcien'cy -of the ftool employed for setting them.

lThis invention .provides a tool 'which `is rcompact, vlight weight and readily manipulated by anoperator. .It may be held and operated 'in one hand. rThe tool :is self- Aindexing at each end .of its operation. Thus, it Aalways twists the .tabs a predetermined .number 'of degrees vand automatically returns to its initial position so that it .may .be quickly 4placed upon :the .next tab .or set of Stabs.

Its operationis rapid and effects :a ',postive, itig'ht engagement between lthe tabs Yand the :chassis to which :the comlponent is mounted.

The tool is of simple and durable construction.

The number of degrees each tab is twisted in .effecting the `lock may be readily adjusted, depending nipon the size and material of the -tab ,and any other .special .cin cumstances of the installation. The .tool is so constructed that lthe operator has .-no .reaction `from its actuation. Itis, thus, less .tiring upon theoperator'andmay be used with greater accuracy.

These and other objects and advantages of this invention will be readily seen by those acquainted with `the design of portable tools upon reading 'the following specication and the accompanying drawings.

In the drawings:

Fig. 1 is a bottom view ofvour invention.

Fig. 2 is a central, sectional, elevation view taken along the plane II--II of Fig. -1. v

Fig. 3 is `a sectional, elevation view taken along 'the plane III-III of Fig. 2 but not sectioning the spindles.

Fig. 4 is an enlarged, fragmentary view of the control valve for the tool sectioning all of the parts except the central plunger and showing the Vvalve in openposition.

Fig. 5 is a fragmentary, central, sectional vfiew ofthe control valve in closed position. i

Fig. 6 is an oblique, exploded view of the casinggand plunger for the valve illustrated in Figs. l4 and: 5. 1

Fig. 7 is a fragmentary,r bottom view of a'-three;sp'indle tab setting tool.

Fig. 8 .is a fragmentary, bottomview of arfourrspindle tab settingftool.

l eating with the interior ofA the plunger by mean A2,802,286 Patented Aug. 20, 1957 ICC yend of-the tool are one-or more'spindles mounted ateright angles fto the rod and each equipped -with agear meshing with the 'teeth o'f the rod. The tool is Vequipped with v'a valve which, when opened, admits air behind the ipiston extending the rod. This 'rotates `the .spindles and twists the tabs. Uponclosure f the'valve, the ainbeh'ind the piston is ported to exhaust and a spring automatically returns the piston to its original position. The return of the rod rotates the spindles Vback to their initial setting.

Adjustments Vare provided -to positively position the spindles in a predetermined position at each end o f the stroke. The pressure-exerted bythe spring to return -the piston is established at a value too low to retwist the -tabs back to their starting position should the tool still be e'n- .gaged whenthe Vcontrol valve is closed.

Referring specifically to the drawings, 'the numeral 51-'0 yindicates a housing having a rearwardy portion 11 and :a

forward portion .or head 12. The rearward -part has a .forwardly opening .chamber 13 for receiving the piston head '.14. The .chamber 13, at its rearward end, has Yan inlet :passage .15 communicating "valve compartment 16.

.'The valve compartment 16 is a blind bore, vopening through the bottom rface ofthe housing and oriented at a right angle to the axis of the chamber 13. The` passage Y15'extends diametrically across the valve compartment 16 and-communicates at its rearward end with the internally threaded,.airiintakeport `177. .Adjacent the air lintake port the :passage is permanently 4closed by a plug 18. That portion of the passage 51/5 extending'fromthe valve-com partmentl tofthe air intake port 17 does not .enter into .the operation of `the tool. It merely provides a imeans of access for drilling the passage 15 from vthe valve Icom- Ipartment 16 tothe chamber 13; By -drilling 'the'.passage 15 .rearwardly Afrom the chamber -13,it may be eliminated entirely.

The operating passageway Ifor carrying air from 'the intake port 17 to the valve compartment 16 consists `'of ,an upwardly-sloped passageway 19. ,The :passageway 19 communicates with vthe `upper portion 'of the valve corn- .partment 16.

Seated inthe valve `compartment 16 is a valve assembly 24 (Figs. 2, 4 and 5). The openend of the valve compartment 16 is internally threaded to receive the .threaded end of Vthe casing '25. The casing 25 is tubular and has a central portion 26 of reduced diameter except -foran Iannular -rib 27 -on its inner end. The rib 27 Ais 'designed to 'form Ian 'air tight seal against the shoulder '.28Lin the compartment '16. "The central portion '26 form's an .annular air passage :29 having upper and lewer -

d iametrical ports

30 and 31 respectively, communicating .between thefpassa'ge 29 and the vinterior chamber-320i the casingiCF-igv). f

'Slidabl-y `mounted within the cas/ing .'25 is aplufnger fhaving :an 'outer .end portion .37 .'of .such diameterthalt itfclosely but :slidably seats lwithinthe 'casing 25. Aipproxim'ately rmidway "between thevends kof 1the"fplun'g'e'r 36 fis anxeriternal, circumferential .channel Sic'om diametrical Jop'eningfli eluppergend offthe plunger C3 gasket 42. When the valve is closed, the gasket 41 seats against the inner end of the casing 25, forming a pneumatic seal (Fig. 5).

The diametric opening 39 at the base of the annular channel 3S 4communicatesl with a blind, concentric opening 43 in the outer end of the plunger 36. The opening 43 discharges through the outer `or lower end of the plunger (Fig. 5). The plunger 36 is retracted by the handle or trigger lever 44. The trigger 44 is pivotally mounted to the rearward end of the tool by the pin 45 (Figs. 1 and 2). The plunger 36 is extended or closed by air pressure on the plunger head 41.

The piston 14 consists of a head plate 50 and terminal Washer 51 having a gasket 52 clamped between them. While the gasket 52 is illustrated as having its marginal portions paralleling the sides of the cylinder 13 it will be recognized that an O-ring type gasket may be substituted without in any way affecting the function of the piston.

The forward portion of the housing or head 12 has a central, axial aperture 56. The aperture 56 is enlarged and threaded at the forward end to receive the externally threaded collar 57. The inner end of the collar 57 has an inwardly turned flange 58 to receive the end of the piston rod 59. The collar 57 is adjustable axially of the aperture 56 and is locked in any selected position by the nut 60.

Seated in the aperture 56 is the piston rod 59. The outward end of the piston rod extends into the collar S7 and has a head 61 of such diameter that it will not pass through the opening in the ange 58. The head 61 has a slot for receiving the end of a tool to hold it stationary when the piston rod 59 and piston head 14 are assembled. The rearward end of the piston rod extends through the piston 14 and is secured by a nut 65. The nut 65 also serves to clamp the washer 51 against the gasket 52.

The piston rod, throughout substantially its entire length, has a plurality of equally spaced, circumferential ridges forming teeth 66. The teeth 66 permit the piston rod to act as a rack. Since the teeth extend entirely around the piston rod, the rod may be installed without consideration to its circumferential position.

The rearward end of the central opening 56 is enlarged and seats the end of a spring 67. The spring 67 is of the compression type and encircles thev piston rod 59. Its rearward end bears against the piston head 14 and. serves as the resilient means for returning the piston head 14 to its original position at the end of I each operating stroke.

The rearward end of the head 12 is of sufficiently reduced diameter that it may be snugly received into the forward end of the chamber 13. The rearward housing 12 and head 11, after assembly, are detachably secured by screws 68.

The head 12 of the housing has a pair of vertical openings 70, one on each side of the aperture 56 (Fig. 3). The openings 70 are normal to and equally spaced from the aperture 56. The lower portions of the openings 70 are of enlarged diameter, creating a shoulder 71. The upper portion of each of the openings 70 has a press-tted bushing 72 to receive the upper end of a spindle 73.

Each of the spindles 73 is equipped with a gear 74 bearing against the shoulder 71 and meshing with the teeth 66 of the piston rod S9. The existence of the shoulders 71 limits upward movement of the spindles 73. The spindles 73 are supported against downward movement by a bushing 75, press-fitted into the lower portion of the openings 70 and forming a lower bearing surface for the gear 74.

In the form of theinvention illustrated in Figs. 1, 2 and 3, a pair of spindles 73 are used. The spindles 73 are aligned'onan axis normal to the piston rod 59.

Each spindle is equipped with a removable tip 76. The tips have a downwardly opening terminal slot 77 for receiving the tab which is to be twisted. The use of removable tips permits rapid adaptation of the tool from tabs of one thickness and width. This is desirable since it is important that the tabs fit easily but closely into the slots 77 to assure a proper twisting action and a firm bond between the tabs and the surface of the chassis to which they are being attached.

Modifications Fig. 7 illustrates the tool adapted for installing components equipped with three tabs. The tool 10a is identical except that the forward portion or head 12a is modied to provide three spindles 73 rather than two. The three spindles are all geared to the piston rod 59 and, thus, are simultaneously operated. It will be noted in this case that whereas the slots 77 of the tool 10 are parallel, the slots 77 of the tool 10a are arranged tangentially to a common circle. It will be recognized that while this shows a preferred arrangement, the slots 77 may be set in any angular relationship to t the orientation of the tabs on the particular component to be secured.

Fig. 8 illustrates a modification of the tool to accommodate components having four mounting tabs. In this case, the tool 10b has four spindles with their slots 77 arranged tangentially to a common circle. Again, vthis particular arrangement is merely illustrative of a preferred form and is not to be considered a limitation upon the application of this invention. The spindles 73 of the tool 10b are geared to the common piston rod 59 and thus are adapted to simultaneous operation. The head 12b of the tool 10b is the same as the head 12 except for the modication to provide openings to accommodate four spindles rather than two.

It will be recognized that while two, three and four spindle arrangements have been illustrated, the tool can be made to accommodate a greater or lesser number of spindles, if desired. These would be merely routine modifications of the tool to meet installation requirements.

Figs. 9 and 10 illustrate another modification of the tool in which the spacing of the spindles may be adjusted to engage tabs of different spacings. Inl this case, the head 12C of the housing is somewhat larger than the heads used on the tools having non-adjustable spindles. The piston rod 59 and its operating mechanism remain the same as does the stationary spindle 73.

The other spindle 73a, however, is mounted in a pair of bushings 80 one on each side of the gear 81. Each of the bushings 80 is press-tted into a guide block 82. The head 12e is slotted at 83 and the guide blocks are slidable in this slot. Thus, the spacing between the

spindles

73 and 73a may be changed by sliding the guide blocks 82 along the slot. The guide blocks 82 may be locked in any position along the slot 83 by tightening set screws S5. The spindle assembly is held against vertical movement in the housing by the side shoulders 84.

The spindle 73 is secured by means of press-fitted bushings a on each side of the gear 81. The gears 81 are identical to the gears 74 except, because of the space limitations, they may be of slightly smaller diameter.

Operation With the trigger 44 released, the valve 24 is ported to atmosphere (Fig. 5) andthe piston 14 rests at its rearward limit of travel (Fig. 2). In this position, the slots 77 in the ends of the spindles are properly aligned to receive the tabs of the particular component with which the tool is being used.

The tool is engaged by placing the spindles over the tabs, causing the tabs to enter the slots 77. The trigger 44 is then depressed, moving the plunger 36'inwardly.

This admits air to the chamber 13 at the rear of the piston 14 forcing it forward rapidly. As the piston 14 moves forwardly, the teeth spin the gears 74, thus rotating the spindles 73. This action twists the tabs, locking the component into place. When the piston 14 reaches the forward end of the chamber 13, its forward motion is stopped. This determines the degree of twist imparted to the tabs. This preferably is an arc of approximately 90 degrees.

The tool is then lifted, disengaging the spindles from the tabs and the trigger 44 released. Upon release of the trigger 44, the pressure of the air bearing against the head 41 of the plunger 36 of the valve forces the plunger outwardly, closing the valve. Simultaneously, the openings 39 align with the apertures 31 in the casing, porting the valve to the exhaust channel 'This discharges the air from the chamber 13, permitting the spring 67 to force the piston head 1 4 back to its original position. This movement of the piston head reverses the rotation of the spindles, returning them to their initial position ready to receive the next pair of tabs. This entire sequence of operation is executed very rapidly, permitting the tool to install components as fast as the operator can move the tool from one component to another.

To determine the length of stroke of the piston rod 59 and thus the degree of twist given to the tabs, the starting position of the piston head 14 is adjusted. By loosening the nut 60, the collar 57 may be moved forwardly or rearwardly. The position of the collar 57 determines the starting position of the piston rod and thus the total length it can travel when actuated. When the proper length of stroke has been set, the tips 76 are adjusted to align the slots 77 with the tabs of the particular components being installed.

The operation of the tool is the same irrespective of the number of spindles employed and irrespective of whether the spacing of the spindles is iixed or adjustable.

In some operations it may be desirable to close the end of the collar 57 to prevent the entry of foreign particles. This may be done simply by placing an internally threaded cap over the end of the collar S7. This cap must have a small port to allow the discharge and intake of air from the interior of the collar and from behind the piston 14 to permit proper operation of the piston.

While we have described a preferred embodiment of our invention, together with several modifications thereof, it will be recognized that other modications of the invention may be made without departing from the principles disclosed herein. Each of these modifications is to be considered as included in the hereinafter appended claims unless these claims by their language expressly state otherwise.

We claim:

1. In a pneumatically operated tool for rotating the end of a strip of material, the combination comprising: a housing having a chamber; a conduit for admitting air under pressure to one end of said chamber; a piston in said chamber adapted to be pneumatically urged in one direction; resilient means for urging said piston in the opposite direction; a toothed rack secured to said piston and movable therewith; a pair of work engaging spindles rotatably mounted to said housing one on each side of said rack, said spindles each having a gear thereon meshed with said rack whereby said spindles rotate oppositely of each other; said housing having an internally threaded opening concentric of said rack; an externally threaded Collar adjustably received in said opening; a radially inwardly extending flange on the inner end of said collar having an aperture therethrough; one end of said rack projecting through said aperture and having a head on said end adapted to seat against said flange whereby the axial position of said collar limits the retraction of said piston and rack under the urging of said resilient means.

2. fn a pneumatically operated tool for rotating the end of a strip of material, the combination comprising: a housing having a chamber; a conduit for admitting air under pressure to one end of said chamber; a piston in said chamber adapted to be pneumatically urged in one direction; resilient means for urging said piston in the opposite direction; a toothed rack secured to said piston rand movable therewith; a pair of work engaging spindles, one on each side of said rack; means for rotatably securing each of said spindles to said housing; one of said means being movable axially of said rack; a fastener element for securing said one means against movement; a gear secured to each of said spindles, each of said gears being meshed with said rack.

3. In a pneumatically operated tool for rotating the end of a strip of material, the combination comprising: a housing having a chamber; a conduit for admitting air under pressure to one end of said chamber; a piston in said chamber adapted to be pneumatically urged in one direction; resilient means for urging said piston in the opposite direction; a toothed rack secured to said piston and movable therewith; a first work engaging spindle rotatably mounted to said housing on one side of said rack; said rst spindle having a gear thereon meshed with said rack; an elongated slot in said housing on the other side of and parallel to said rack; means slidably mounted in said slot for movement parallel to said rack; a second work engaging spindle rotatably mounted to said slidable means; a gear on said second spindle meshed with said rack; a locking element adapted to hold said slidable means against movement along said slot.

4. In a pneumatically operated tool for rotating the ends of a pair of strips of material, the combination comprising: a housing element having a chamber; a conduit for admitting air under pressure to one end of said chamber; a plunger element including a piston and a rack; said piston being mounted for reciprocation in said chamber and adapted to be pneumatically urged in one direction; means acting between said plunger element and said housing element to retract said plunger; said rack being toothed and secured to said piston and movable therewith; a pair of work engaging spindles having work engaging means at one end thereof and rotatably mounted to said housing; each of said spindles having a gear meshed with said rack, one on each side thereof whereby said spindles rotate simultaneously in opposite directions; means adjustably mounted on one of said housing element and said plunger element and contacting the other thereof for limiting the retraction movement of said plunger whereby the position of said work engaging means is indexed when said plunger is retracted.

References Cited in the file of this patent UNITED STATES PATENTS 631,698 Cowles Aug. 22, 1899 734,276 Metcalf July 21, 1903 1,043,399 Cole Nov. 5, 1912 1,385,289 Ward July 19, 1921 1,823,426 Ferris Sept. 15, 1931 1,825,290 Stevens Sept. 29, 1931