US3368659A

US3368659A - Shock-absorbing typebar stop

Info

Publication number: US3368659A
Application number: US628092A
Authority: US
Inventors: Erle R Mumpower
Original assignee: NCR Corp
Current assignee: NCR Voyix Corp; National Cash Register Co
Priority date: 1967-04-03
Filing date: 1967-04-03
Publication date: 1968-02-13
Anticipated expiration: 1985-02-13
Also published as: DE1984628U; FR1573086A; GB1153965A

Description

Feb. 13, 1968 E. R. MUMPOWER 3,368,659

SHOCK-ABSORBING TYPEBAR STOP Filed April 5, 1967 22 FIGJ I 1 WI 1% 24 "ii i 30 28 v2o 26 J-' INVENTOR 4 HIS ATTORNEYS United States Patent 3,368,659 SHOCK-ABSORBHWG TYPEBAR STOP Erle R. Mumpower, Kettering, Ohio, assignor to The National Cash Register Company, Dayton, Ohio, a corporation of Maryland Filed Apr. 3, 1967, Ser. No. 628,092 2 Claims. (Cl. 19742) ABSTRACT OF THE DISCLOSURE A shock-absorbing stop to minimize rebound of typewriter levers. The stop includes an arcuately-shaped member which is yieldably supported near each end on springloaded pins for movement towards a similarly-shaped support member. Each lever, upon returning to a home position after printing, strikes an elastomer strip secured to the movable member and moves it towards the support member to thereby prevent rebound of the lever and minimize the noise of impact.

Background of the invention This invention relates to a shock-absorbing stop, and, more particularly, it relates to a shock-absorbing stop which is especially adaptable for use with typewriter levers to prevent the rebounding thereof when the levers return to a home position after hitting the platen of the typewriter or similar machine in which the stop is used.

Resilient shock-absorbing stops to prevent typewriter lever rebound are known; however, the prior-art constructions wear rapidly when subjected to extensive use. This is especially true when the prior-art constructions are used with electric-power-0perated typewriters, whose returning typewriter levers have comparatively large amounts of kinetic energy to be transferred to the shockabsorbing stops upon impact thereagainst. Because the electrically-operated typewriters operate at high speeds, it is also necessary that the shock-absorbing stops used therewith quickly absorb the kinetic energy of the returning levers.

The shock-absorbing stop of this invention quickly absorbs the impact energy of typewriter levers returning to a home position after striking the platen of the typewriter in which the stop is used. Said stop is inexpensive to produce and has sufficient flexibility and responsiveness to be effective even when used with light-weight typewriter levers which are operated at high speeds.

Summary of the invention The shock-absorbing stop of this invention includes a .first elongated member, which has end portions adapted to be secured to a support in a typewriter or other similar printing machine with which said stop may be used. The stop also includes a second elongated member, having first and second opposed sides thereon with a strip of resilient material secured to said first side. When said stop is used in a typewriter, the typewriter levers actually rest upon said strip when the levers are idle, or in the home position. The stop also includes resilient means secured to said second side for yieldably maintaining said second member in spaced relation with said first member, whereby at least a portion of said second member is moved towards said first member when one of said typewriter levers impacts against said strip in returning to said home position after striking the platen in the machine in which the stop is used.

Brief description of the drawings FIG. 1 is a side view in elevation of the shock-absorbmg stop of this invention as used in a typewriter.

3,368,659 Patented Feb. 13, 1968 Description of the preferred embodiment FIG. 1 shows the shock-absorbing stop 10 of this invention as used in a typewriter. The

levers

12, 14, 16, and 18 are connecting levers used to actuate the typewriter levers 20 to move them individually to strike the platen 22. Because said connecting levers are conventional and do not form a part of this invention, they are shown only generally, so as to orient the stop 10 within the structure of a typewriter. The levers 20 are shown in the home position, resting on the resilient strip 24 of the stop 10. After each individual lever 20 is actuated to strike the platen 22, it rebounds therefrom to impact against the stop 10, which is adaptable to quickly absorb the kinetic energy of the impacting lever 20.

The construction of the shock-absorbing stop 10 is best shown in FIG. 2. The stop 10 includes a first, generally arcuately-shaped, elongated member 26, having end portions 28 adapted to be secured to a support 30 (FIG. 1) by fasteners 32. Positioned adjacent to said first member 26 is a second, generally-arcuately-shaped, elongated member 34, which has the resilient strip 24 secured to one side thereof by conventional adhesives. The strip-24 is made of elastomeric material, such as vinyl chloride, and, in the embodiment shown, was approximately inch thick.

The second elongated member 34 is yieldably held in spaced relation to the first elongated member 26 by the following construction. Each end of the elongated member 34 is secured to the elongated member 26 by a resilient means 36, having the arrangement shown in FIG. 4, which includes a stud or pin 38 projecting from one side of said member 34. The stud 38 extends through a slot 40 in the first elongated member 26, anda compression-type spring 42 is mounted on the stud between the

members

34 and 26, suitable washers 44 being positioned on the stud on opposite sides of the slot 40 in the member 26, as shown. A second compression-type spring 46, producing slightly less compression than the spring 42, is also mounted on the stud 38 between one of the washers 44 and a washer 45, a retaining C-shaped clip 48 being used to retain the spring 46 on the free end of the stud 38. By this construction, the area near each end of the second elongated member 34 is provided with a resilient means 36, which may act as a pivot point for the opposite end of said member 34 when a typewriter lever 20 strikes said opposite end. Also included in this construction is a third stud 52, which projects from the second member 34 (FIGS. 2 and 3) and passes through an opening 50 in the'first member 26; both sides of the opening 50 are countersunk.

The operation of the stop 10 is as follows. When an object, such as a typewriter lever 20, strikes the resilient strip 24 near one of the resilient means 36 (the one shown in the left side of FIG. 2, for example), its spring 42 is compressed somewhat against its bias, and the second member 34 is resiliently moved towards the first member 26, thereby absorbing some of the kinetic energy of the impacting lever 20. Some of said energy is also absorbed by the resilient strip 24, which deadens some of the noise of impact. In addition, when the left end of the member 34 (as viewed in FIG. 2) moves toward the member 26, the right end of the member 34 is moved slightly away from the member 26 due to a slight pivoting of the member 34 about the stud 52, which is located approximately in the center of the length of the member 26. In normal operation, all the typewriter levers 20 rest upon the resilient strip 24, as shown in FIG. 1; however, when one end of said member 34 moves away from the member 26, as mentioned in the previous sentence, the levers 20 resting on said one end are also moved with it, thereby absorbing some of the said kinetic energy. The springs 46 then assist in restoring the second member 34 to the static position, shown in the drawings. When a lever 20 impacts against said resilient strip 24 near the center of the second member 34, the center of the member 34 (near the stud 52) moves toward the member 26 against the bias of the springs 42 to absorb most of the kinetic energy of impact. The resilient strip 24 also absorbs some of the kinetic energy.

The particular size of the

springs

42 and 46 and the other elements in the stop are determined by the particular application in which the stop is used. The particular stop 10 shown herein is responsive enough to be used with typewriter levers 20, which are considered lightweight in the art.

While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein Without departing from the spirit and scope of the invention.

What is claimed is:

1. A shock-absorbing stop adapted to be secured to a support and comprising:

a first elongated, arcuately-shaped member having end portions adapted to be secured to said support;

a second elongated, arcuately-shaped member having first and second opposed sides thereon, and first and second opposed ends;

a strip of elastomer material secured to said first side of said second member;

a stud projecting from said second side near each said end of said second member;

said first member having slots therein to receive said studs, with each said stud being of sufficient length to provide a section which extends through and beyond its pertaining said slot;

a first compression-type coil spring mounted on each said stud between said first and second members;

a second compression-type coil spring mounted on each said section between said first member and the free end thereof; and

fastener means to secure said second springs on the free ends of said sections and to subject all said springs to a slight compression;

said slots being of sufiicient size to enable one end of said second member to move towards said first member against the bias of at least said first springs when an object impacts said strip near said one end while said second member is pivoted about a point near its opposite end.

2. The stop as claimed in claim 1 in which all said first springs provide a slightly greater compressive force 7 than said second springs and yieldably maintain said second member in spaced arallel relation with said first member, and in which said first member has a hole in the center thereof, said second member also having a third stud projecting from said second side thereof and adapted to extend through said hole to assist in maintaining said second member in said spaced parallel relation with said first member, and to provide 'a pivot point for said second member when an object impacts said strip near one said end of said second member.

References Cited UNITED STATES PATENTS 884,347 4/1908 Yetman l97--42 XR 886,570 5/1908 Young 197-42 2,043,393 6/1936 Pasinski l9742 XR 2,176,123 10/ 1939 Denzer 197-42 ROBERT E. P-ULFREY, Primary Examiner.

E. S. BURR, Examiner.