US1196021A - Work support controlling mechanism - Google Patents

Description

G. PEGG.

WORK SUPPORT CONTROLLING MECHANISM.

APPLICATION FILED 001.17, 1912.

1,196,021. 1 PatentedAug. 29,1916.

2 SHEETS-SHEET I.

vl/mvissgsi Fig.1;

G. PEGG.

WORK SUPPORT CONTROLLING MECHANISM.

APPLICATION nuzn OCT-17.1912.

1,196,021. I Patented Aug. 29,1916.

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2 SH SHEET 2- l WT/VESSES support into operative position.

increase of speeds 1n fastening lnsertmg UNITED STATES PATENT OFFICE,

GERALD PEGG, 0F LEICESTER, ENGLAND, ASSIGNOR TO UNITED SHOE MACHINERY COMPANY, OF PATERSON, NEW JERSEY, A CORPORATION OF'NEW JERSEY.

Specification of Letters Patent.

Patented Aug. 29, 1916.

Applicationifiled October 17, 1912. Serial No. 726,282.

To all whom it may concern:

Be it known that I, GERALD Pass, a subject of the King of England, residing at Leicester, Leicestershire, England, have invented certain Improvements in Work-Sup port-Controlling Mechanisms, of which the following description, in connection with the accompanying drawings, is a specification, like reference characters on the drawings indicating like parts in the several figuresl This invention relates'to work supports for nailing or other machines used in the manufacture of boots and shoes, and more particularly to the mechanism by which the operation of the work support is controlled.

In fastening inserting machines it is usually desirable that the work be clamped at the time the fastening is inserted, and for this purpose it has been customary to employ a spring, since a spring furnishes the most simple and inexpensive means of adjusting the work support automatically to the different thicknesses of the work. The spring is also utilized to raise the work With the machines, it has been found, however, that the spring is not wholly satisfactory as a means for clamping the work unless a very powerful spring is used, and that when the strength of the spring is increased to in sure proper clamping action it interferes with the proper operation of the horn re lease mechanism. In other words, when a very powerful spring isvused it has been found difficult to depress the horn with the degree of accuracy and uniformity desir-. able for feeding the work or to hold it depressed for the removal or insertion of the work, and furthermore the impact of the support under action of the powerful spring as the support returns to clamping position has an injurious effect upon the work. To overcome these difficulties a spring of medium strength has been used in some machines to raise the work support into operative position, and it has been proposed, in conjunction therewith, to provide a device for locking the work support in this position so as to provide a rigid support to sustain the impact of the driver; Various constructions of such locking devices have been proposed and some have been satisfactory when dealing with certain classes of work but unsatisfactory when dealing with other classes. Others have been so complicated and cumbersome that their incorporation in the machine has entailed considerable increase in its cost. In connection with loose naillng machines particularly, considerable difliculty has been experienced when using heavy nails and it has been found that the nails have not been inserted to uniform depths in the work, which, of course, cletracts considerably from the appearance and consequently from the value of the finished article. 1

An object of the present invention, therefore, is to provide an improved locking device for a work support in order to overcome as far as possible the difficulties hereinabove pointed out. Accordingly for a nailing or other machine used in the manufacture of boots and shoes and having a work support, a device tending normally to raise the work support to work supporting position, automatic means to depress it to work feedingposition, and manually operable means to depress it into work receiving position, there is provided a lock which is normally in action to lock the work sup port to the machine frame in order to prevent movement of the work support from work supporting position, combined with mechanism connected to the said automatic means to release the look upon the work support, the arrangement being such that the said automatic means releases the lock before acting to depress the work support. Conveniently there may also be provided an appliance that is connected to the said manually operable means to release the lock upon the work support before acting to depress the work support. Preferably the timing of the release of the lock with relation to the depression of the work support is obtained in either case by means of lost motion connections.

In the construction illustrated, the locking device comprises a roller that operates upon a single member of the horn supporting mechanism between fixed portions of the machine frame, thus eliminating the lost motion, or backlash which is likely to occur if the work support is locked to a moving part of the mechanism, owing to the wear at the joints and to the flexibility inseparable from a moving part, which in a machine operating at high speed must necessarily be light. The roller is arranged to be normally pressed into operative position under the action of a spring, thus insuring that the lock is always in action eX- cept at those times when it is definitely re leased. Release of the lock to permit depression of the work support for feeding is effected automatically at each cycle of operations and the release to effect depression of the work support to work receiving position is arranged to be effected at any time by means of a treadle which also depresses the work support. In the construction to be described, both these releases are effected by the operation of wedges or cams upon a lever which is arranged to contact with and depress the locking roller, the wedge or cam being operated in the one case automatically by the same cam which operates the horn depressing mechanism and in the other case by the treadle which is arranged to depress the horn Whenever desired.

The invention will now be described as embodied in a loose nailing machine, but it is to be understood that it is not confined to this type of'machine since it could. equally well be embodied in other machines, and moreover it is to be understood that the details of construction could be varied without departing from the spirit ofthe invention.

In the accompanying drawings,Figure 1 is a side elevation of a loose bill nailing machine in which is embodied one construction of the present invention; Fig. 2 is an elevational detail to an enlarged scale. of part of the mechanism by which the locking. device is released to permit the lowering of the work support; Fig. 3 is a side elevation, partly in section, of the locking device and its releasing mechanism; Fig. 4 is a back elevation, partlyin section, of the mechanism shown in Fig. 3; and Fig. 5 is a plan, partly in .section, of certain of the parts shown. in Fig. 3..

Like reference characters. indicate like parts in all the figures.

The work-supporting horn 2 is raised into operative position by means of a spring 3 and is pivotally connected at 1 to the outer end of a horn lever 6 that is fulcrumed between its ends at 8 in the base of the machine. The horn lever has pivotally coupled to its inner end at 10 a link. 12 adjustably connected to a slider 14' arranged-to, recip. rocate 1n guldeways formed inthe machine frame to effect depresslon of the horn. Upon the slider are a numberofratchet teeth 16 is in lowermost position the pawl is withwill in turn raise the slider 1'1: and with it the inner end of the horn lever, thus depressing the outer end of the horn lever and consequently the horn 2. This occurs at the appropriate time to permit the feeding mechanism to feed the work. At other times, e'. 6., when the pawl holder is in'its lowermost position, the pawl is held by the before-mentioned shield out of engagement with the ratchet teeth 16' so as to permit relative adjustment. I i

The depression of the horn to insert 01' remove the work is obtained by means of a treadle 2 1 which is pivoted between its ends in the baseof themachine at 8 and which is adapted to cause an abutment 26 near its inner end to contact with a corresponding abutment 28 upon the inner end of the horn lever 6 to raise that end of the horn lever and to depress the end supporting the horn.

The mechanism so far described is substantially the same as that used in connection with an ordinary loose nailing/machine of the type being described.

In the present construction, a. considerably lighter spring than usual is employed to raise the horn into work-clamping position and it"is therefore requisite that a lock" to permit it to be depressed by the treadle to release the Work so" that the latter may be removed from the machine or new'work placed therein. v v

The locking device will now be described. Projecting from the frame of the machine in proximity to the slider 14; is a bracket 30 upon a portion of which is fixed a thrust block 32 having an inclined face 34; Between this inclined face and the adjacent surface ofja strip 36 inserted in the slider" 14 there is provided a roller38 which is adapted to be upheld by means of a spring plunger 10 located in a lug 12 projecting from the thrust block 32, the arrangement being such that the spring tends to force the roller between the inclined face 34 crime thrust block andthe adjacent surface ofithe strip 36 and so cause theslider to be held between the bracket and the machine frame against upward. movement under ,any ordinary stress. Thus the roller acts" under normal conditions as an automatic locking, device that ispermanently in engagement and that does not require to be applied by a separate power-operated device.

- or convenient manner.

In order that the pawl 18 may be able at the proper timeto raise the slider and so affect depression of the horn for the feeding of the work, provision is made for lowering the roll 38 against :the resistance of its spring plungerand so removing it from locking contact with the thrust block and the slider.

Upon a block 44 adjustably mounted in the lower portion of the pawl holder .20 there is provided a Wedge or cam face 46 so positioned as to engage an anti-friction roll 48 upon theend of one arm 50 of a bellcrank lever that is pivoted at 52toa portion of the bracket .30. In :the construction shown, the roll 48 is mounted on an eccentric stud carriedon the arm 50 so that by rotation of the eccentric stud the roll can be adjusted relatively to .the cam faces with which it cooperates. The other arm 53 of this bell-crank lever is provided with jaws that engage one end of a bar 54: fulcrumed between its ends in a block fixed to the bracket 30, the other end of the bar being normally located just out of contact with the roller 38 whenthe latter is in its highest position, that is to say, the position in which its wedging action is greatest. Preferably the end of the bar gripped by the jaws may be made cylindrical and preferably also the fulcrum block may be formed as, or approximately as, knife edges. the construction shown the upper fulcrum edge is formed by the rounded edgeiof a pin 56 screwed into the block so providing .for adjustment to compensate for wear or .for variations in interchangeable parts. The arrangement is such that when the horndropping cam 22 raises the pawl. holder 20 to depress the horn, the wedge face 46 is also raised and by reason of its upward movement the latter forces the arm 50 of the bell-crank lever laterally, thus rocking the bell-crank lever about its pivot and raising the arm 53. This movement of the second arm therefore raises the adjacent end of the fulcrumed bar 54 and depresses the other end which, coming in contact with the roller 38, depresses the latter against the action of its spring plunger and thus frees the slider 1 to permit it to imoveupward-under the action of the pawl 18. This upward movement of the slider depresses the horn to permit the work to be fed.

As already described, the treadle 24 is adapted by meansof anabutment- 26 to depress the horn and raise the slider but it is obvious (as the various connectionsare unyielding) that before this can take place the lock upon the slider must be released. Ac-

cordingly the inner end of the treadle lever has pivotally connected to it at 58 a rod 60 extending upward into proximity to the upper end ofthe arm 50 of the bell-crank lever. The upper end of this rod is provided with a wedge or cam face 62 which is shaped-similarly to the cam face 46 and which is similarly placed adjacent to the roll 48 on the end ofthe arm 50. The arrangement is such that depression of .the treadle 24 raises the innerendof the treadle lever and with it the associated rod 60 so as to bring the wedge face 62 into action upon the bell crank to release the horn-locking roller 38.

In order that the lock may be released somewhat before the slider is acted upon a small amount of lost motion is provided, preferably between the abutment 26 and the corresponding abutment 28 so that the roller will be depressed to unlock the slider before the inner end of the horn lever is raised to raise the slider and consequently depress the horn. Thus provision is made for releasing the lock upon the slider when it is desired to depress the horn by means of the treadle for the removal or the insertionof work.

In the case of the power-operated horndrop motion, the pawl holder 20 is moved sufliciently downward after the pawl has disengaged from the ratchet teeth to provide on its return that amount of lost motion which is requisite to enable the locking roll to be released before the pawl reengages the ratchet teeth to start depressing the horn.

Having described my invention, what I claim as new and desire to secure by Letters Patent ofthe United States is 1. In a machine of the class described, a work support yieldingly pressed into work supporting position when the machine is at rest, a spring operated lock acting automatically to lock the work support to the machine frame against movement from any work supporting position into which it may be yieldingly pressed, automatic means for intermittently depressing the work support into work feeding position, and means operated by said depressing means to release said lock inorder to permit the action of said depressing means upon the work support.

v2. In a machine of the class described, a work support, a spring operating to maintain it in work supportingposition when the machine is at rest, spring operated means acting .upon movement of the work support into work supporting position to lock the work support to the machine frame against movement toward work receiving position from any work supporting position into which it may be moved by its spring, said means being constructed to permit free movement of the work support into work supporting position, automatic means for intermittently depressing the work support to work feeding position, comprising work thickness compensating connections whereby uniform depression is obtained for varying thicknesses of work, and means operated by the depressing movement of said automatic means to release the locking means, said releasing means being arranged to release said look before said work thickness compensating connections become operative.

3. In a machine of the class described, the combination with a work support, means tending normally to raise it to Work supporting position, automatic means to depress it to work feeding position, and manually operable means, to depress it to work receiving position, of a spring operated lock acting normally tolock the work support to the machine frame against movement from any work supporting position into which it may be raised by said first-mentioned means, means connected to the manu ally operable means to release the look upon the work support to permit said means to depress the work support, and means operated by the depressing movement of said automatic depressing means to release saidlock to permit the action of said automatic means upon the work support.

l. In a machine of the class described, a work support, means tending normally to raise the Work support into work supporting position, automatic means for intermittently depressing the work support into work feeding position, said automatic means comprising work thickness compensating connections, including a pawl and a ratchet mem-. ber, whereby uniform depression may be obtained for varying thicknesses of work, spring operated selflocking means acting automatically when the machine is at rest to lock the work support to the machine frame against movement from any work supporting position into which it may be raised by said first-mentioned means, and

means connected to the pawl carrier arranged to act upon said locking means to release said look before the 'pawl engages the ratchet member.

5. In a machine of the class described, a work support yieldingly pressed normally into work supporting position, a spring operated lock acting when the machine is at rest to lock the work support to the Ina-- chine frame against movement from any work supporting position into which it may be yieldingly pressed, automatic means for intermittently depressing the work support into work feeding position, said means comprising a. reciprocating member and a second member constantly connected to the work support and arranged to be connected to said Copies otthis patent may be obtained for reciprocating member after said member has 6. In a machine of the class described, a

work support yieldingly pressed normally into work supporting position, automatic means for intermittently depressing the work support into work feeding position, comprising relatively movable members arranged to be connectedat a predetermined time in the operation of the machine and at different points in their relative move ment according to the thickness of the work, one of said members being constantly connected with the work support, means, com prising a spring pressed roll, tending normally to lock said last-mentioned member to the machine frame, and means connected to the other member and operated thereby before said members are connected to move said roll out of operative locking position. a

7. In a machine of theclass described, a work support yieldingly maintained normally in work clamping position, treadle operated means to depress said'work support into work receiving position, self-locking meansoperating automatically to lock said work support whenever it is in work clamping position, automatic'means for intermittently depressing the work support into po sition to permit the work to be fed, means movement between said positions in one 'direction while permitting free movement of said work support in theopposite direction, automatic means for intermittently depressing the work support into position to permit the work to be fed and means operated by said depressing means to release said looking means to permit said depressing'means to lower the work support.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses,

GERALD PEGG. Witnesses: V FREDERICK WILLIAM WORTH,

JOHN "RIOHA'RD LAW,

five cents each, by addressing the Commissioner of Patents, Washington, I). G,

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