US1024491A - Stop-bar. - Google Patents

Description

J. S. BANGROFT & M. C. INDAHL.

STOP BAR f APPLICATION FILED AUG. s, 1911.

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WMe/aow Willi Patented Apr. 3o, 1912.

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JOI-IN SELLERS BANCR-OFT AND MAURITZ C. INDAHL, OF PHILADELPHIA, PENNSYL- VANIA, ASSIGNORS T0 LANSTON MONOTYPE MACHINE COMPANY, OF PHILADEL- PHIA, PENNSYLVANIA, A CORPORATION O'F VIRGINIA.

snor-BAR.

Specification of Letters Patent.

Patented Apr. 30, 1912.

To all whom it may concern:

Be it known that we, JOHN SELLERS BAN- cRorr and MAURITZ C. INDAHL, of Philadelphia, county of Philadelphia, State of Penn- Sylvania, have invented certain new and useful Improvements in Stop-Bars; and we do'` hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specication, and to t-he figures and letters of reference marked thereon.

This invention relates to improvements in stop bars or racks for centering mechanisms, such, for example, as disclosed in Patent No. 625,998, dated May 30, 1899, and it has for its principal object to diminish the breakage due to t-he impact of the positioning members, and, incidentally, to increase the speed capacity of the machine as a whole.

In the accompanying drawings illustrating a preferred form of embodiment of the invention-Figure 1 is a top plan view; and Fig. 2 a longitudinal vert-ical section of the improved stop bar or rack. Fig. 3 is a perspective View of the detached contact section. Fig. 4 is a section on line 4 4, Fig. 1.

The same numerals designate like parts in the several figures.

By reference to Patent No. 625,998, it will be found that the stop bar-the secondary gage or controller of said patent, and commercially known as the stop rack 7--is the intermediary through which the adjustments imposed by the primary controller or gage upon the aws of the primary positioning or gaging mechanism are transmitted to or imposed upon the jaws of the secondary positioning or ga'ging mechanism in centering the die case and adjusting the normal and justifying wedges.

During each revolution of the driving shaft, co-ext-ensive with a cycle 0f operations, the stop bar receives the impact of both sets of jaws, one set acting while the stop bar is unconlined and free' to move longitudinally, whereby it is translated to the position of adjustment determined by the primary gage, and the other set acting upon the stop bar while` firmly held in its adjusted position by the locking bar, to bring the die case and normal or justifying wedges to the indicated position.

The pressure exerted by the jaws upon the stop bar increases with the speed of the machine, and is a distinct limitation upon its speed capacity. The maximum pressure occurs during the closing of the jaws of the secondary positioning or gaging mechanism while the stop bar is locked in position, and is estimated at approximately 400 pounds when running at the rate of 180 revolutions per minute. Such pressure is dangerously near the elastic Alimit of the material and not infrequently results in a rupture of the stop bar, usually in the vicinity of the point of engagement by the locking bar, or of the point of attachment of the jaw-engaging off-set with the body or guiding section of the stop bar. Moreover, the reactionary effect upon ythe connected operating mechanism i's detrimental and contributes to a lowering of the speed of the machine.

Heretofore numerous attempts have been made, but with limited success, to eliminate or materially diminish this speed retarding factor, for while the stop bar is a distinct and separable element, its form and dimensions are limited and determined by those of the associated parts of the machine as a whole, and any material change in these respects would involve a more or less radical change in the present organization.

The remedy proposed and accomplished by the presentinvention consists essentially in providing the stop bar with a self-contained buifing mechanism competent to maintain or restore t-he jaw engaging and locking sections in cooperative relation and to yield when required and thereby sufficiently enlarge the time element so as to prevent the development of excessive or breaking pressure. To these ends the stop-bar is formed in two sections, a guiding or body section 1, and a jaw engaging section 2. The body section 1 conforms externally in form to that of the prior stop-bar, and in addition to the usual series of locking teeth 3, it is provided with a longitudinal slot or recess 4, preferably terminating at opposite ends in hemi-cylindrical bearings 5. For a purpose to be hereinafter explained, the lower portion of slot 4 is extended to form an undercut bearing 6 at the end of the body remote from that containing teeth 3.

The jaw engaging member extending transversely trom the body section is provid Vd with a lateral extension 7 at its base adapted to tit within slot t in the body section and provided with a slot or opening 8 tor the reception ot a spring 9, the latter interposed between two blocks or bearing pieces 10, each engaging one end ot slot 8. llhe end ot extension T remote from aw-engaging section 2, is cut away on its upper surtace to enter beneath bearing 6 and is also provided with a longitudinal opening tor the reception ot a pin 11, the inner end of which taires a bearing upon block 10, while the outer end engages bearing 5 at one end ot' the slot 1l in body section 1. ln like manner the wall at the opposite end of slot 8 is provided with a longitudinal opening 12 tor the passage ot' a pin 13, the latter engaging the adjacent bloei; 10 and provided with a hemi-cylindrical head contacting with the adjacent bearing 5 in body section 1.

ln practice, a spring 9 exerting approximately 8O pounds pressure is inserted under compression between opposed blocks 10, and pins 11 and 13 being applied, the jaw-engaging section is inserted in the slot ot the body section, by tirst introducing the cut away end ot the extension 7 beneath bearing G, and then tilting section 2 until the laterally extended base 'let o1 the jaw-engaging member rests upon the upper surface ot the body section 1. rlfhe parts are so proportioned that when sections 1 and 2 are thus assembled there will be no appreciable play or lost motion between them and the sectional stop bar as a whole may be substituted tor the integral stop bar as heretofore constructed and used in the commercial machinos.

Under ordinary conditions, the sectional stop bar ope ates the same as the integral; but it excessive pressure is brought to bear upon the jaw-engaging member, in either direction, longitudinally ot the body portion, spring 9, by yielding temporarily, will so extend the time element as to bring the pressure well within the elastic limit of the material, thereby preventing excessive strain upon connected elements and materially reducing the danger' ot fracture, both of said elements and oit the stop bar itself. The reaction ot the .sn-ing will immediately restore the sections to initial position so that the positioning function of the mechanism will not be interfered with to a perceptible extent.

lt has been demonstrated in practice that by the use et' the improved sectional stopbar not only is the danger of breakage at roza/r9 1 heretofore maximum speed practically eliminated, but, owing to the relief atiiorded cooperating elements, the speed capacity ot the machine as a whole can sately be increased in a material degree without danger to its operating mechanism including the stop bars.

TWhat we claim is :M

1. A stop-bar for type casting machines comprising a body or locking section and a relatively movable aw engaging section.

2. A stop bar tor type casting machines comprising a body or locking section, a relatively movable jaw engaging section and yielding connections between said sections.

3. A stop bar 'for type casting machines providedavith a body or guiding and locking section, an independently movable jaw engaging section, and a yieldable connection between said sections tending to maintain the same in a predetermined relative position but permitting independent movement under excessive pressure.

el. A stop bar tor type casting machines provided with a slotted body or guiding and locking section, a jaw engaging section mounted to reciprocate longitudinally of said body section within the slot therein, and yieldable retaining means interposed between said jaw engaging and body sections.

5. A stop bar for type casting machines comprising a body or guiding and locking section, pro-vided with a longitudinal slot or opening; a jaw engaging section supported to reciprocate in said slot and removably applied thereto; and yieldable tensioning means carried by said jaw engaging section and adapted to engage the body section to yieldably maintain said jaw engaging section in a predetermined relation to the body section.

(3. A stop bar tor type casting machines including in combination a. body or guiding and locking section provided with a longitudinal slot or opening; an indepemlently movable aw engaging section guided in the slot of the body section and in turn provided with a slot or recess; a spring inserted under compression between movable bear ings in said jaw engagiiig section; and two 'transmitting members each interposed between one ot said movable bearings and the adjacent end of the slot in the body section.

JOHN SELLERS BANCROFT. MAURITZ C. INDAHL.

lVitnesses FRED VEINDEL, J r., FRANK H. MAssnY.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, ID. C.

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