US3384217A

US3384217A - Type bar rest support

Info

Publication number: US3384217A
Application number: US546911A
Authority: US
Inventors: Carl P Anderson
Original assignee: SCM Corp
Current assignee: SCM Corp
Priority date: 1966-05-02
Filing date: 1966-05-02
Publication date: 1968-05-21
Anticipated expiration: 1985-05-21

Description

May 21, 1968 c. P. ANDERSON TYPE BAR REST SUPPORT Filed May 2, 1966 INVENTOR CARI... P. ANDERSON AGENT United States Patent 3,384,217 TYPE BAR REST SUPPORT Carl P. Anderson, Homer, N.Y., assignor to SCM Corporation, New York, N.Y., a corporation of New York Filed May 2, 1966, Ser. No. 546,911 3 Claims. (Cl. 19'7-42) ABSTRACT OF THE DISCLOSURE A type bar rest support for powered typewriters having a yieldable structure to absorb the energy of the type bars as they return to the basket after printing. The yieldable structure includes an elastomeric member arcuately shaped to be contacted by all of the type bars, and shaped to be guided for radial movement in a rigid support, a pair of arcuate metal strips cemented to the underside of the el-astomeric member, each metal strip extending along approximately one half the length of the support and leaving a slight gap between the centermost ends of the metal strips substantially at the center of the support, and a coil spring extending the length of the support and positioned under the metal strips to bias the metal strips and elastomeric member against the rigid support.

It is well known in the art that almost all the energy of the returning type bar must be absorbed at the moment it strikes the basket to prevent the type bar from rebounding.

The type bar rebound is significant since the typing speed of the machine and the quality of print are, to a point, dependent upon the degree of rebound that occurs when the type bar returns to the basket. More specifically, if the type bar rebound is too high, the type bar may collide with another closely positioned type bar that has already left the basket and is on its way to the printing point on the worksheet. Further, if a repeat action of the type bar has been conditioned and the type bar has not returned to its rest position in the basket after rebounding, the driving force of the type bar is affected which consequently affects the impression or blackness of the printed character on the worksheet.

From an economical and practical viewpoint it is virtually impossible to provide a typewriter basket within the normal confines of the typewriter that will absorb the energy of the type bar so completely that no rebound at all occurs when the bar strikes the basket. However,

there is a degree of rebound that is permissable while still achieving favorable results and hence, the less the degree, the more desirous it becomes.

Patent No. 3,162,288 issued to R. Salto discloses a typewriter basket that achieves these desirous results. However, the basket construction consists of a high number of parts. This type of construction is costly when consideration is given to the unit material, production, and assembly costs.

In todays typewriter industry the popularity of the more compact powered typewriter is rapidly increasing which results in more typewriters that have small confines to which the type bar basket is limited and hence, create a need for a basket that is of a comparatively low silhouette. For example, upon a case shift condition, wherein the basket is shifted to its downward position for printing an upper case character, the basket must be compact enough so as not to interfere or collide with power instrumentalities generally located in the area directly beneath the basket.

The overall size of the Salto structure, particularly its height, would not permit its use in a powered typewriter having these small basket area confines.

Patent No. 2,720,959 issued to R. D. Dodge et al. also discloses a typewriter basket that achieves the desirous rebound results and although unlike the Salto structure, it has relatively few parts, it also, like the Salto structure, produces a basket that is too high for typewriters with small basket area confines.

It is therefore, with these disadvantages considered, the object of this invention to provide an efficient, shock absorbing type bar basket that has a comparatively low silhouette.

A further object of this invention is to provide a compact efficient, shock absorbing type bar basket including two arcuate metal strips separated substantially midway of the basket for assisting in reducing the rebound of the type bars near the ends of the basket as they come to rest on the basket.

Another object of this invention is to provide an improved compact typewriter type bar basket having a minimum number of parts.

Further novel features and other objects of this invention will become apparent from the following detailed description, discussion and the appended claims taken in conjunction with the accompanying drawings showing a preferred structure and embodiment, in which:

FIGURE 1 is a front elevational view of the improved compact typewriter basket showing several type bars resting therein:

FIGURE 2 is a sectional view taken along line 22 of FIGURE 1; and

FIGURE 3 is a right end elevational view of the improved basket.

Referring to the figures and, more particularly to FIG- UR-E l, the basket 10 is mainly comprised of a guide support 12, a resilient unit 14 and a coil spring 16, the combination of which operates to be slightly compressed and radially displaced to absorb the energy of the type bars as they return to the basket after printing.

The guide support 12 consists mainly of an arcuate sheet metal plate 18 having a longitudinal slot 20 that terminates just inwardly of the plate ends and is of a width so as to freely guide an arcuate resilient member 22 for radial movement within the plate in response to type bar impact. The resilient unit 14 is comprised of the resilient member'22 and two rigid elements such as arcuate metal strips 24 that are cemented to the bottom surface of the member 22. The two metal strips 24 are so positioned that their innermost ends 25 are slightly apart from one another. Each metal strip has, midway its width, a curved form 26 extending its entire length for engaging a mating recess 27 in the resilient member 22. A recess 28 in the bottom surface of metal strip 24 provides a 'detent for insuring the location of the tension spring 16 which is slightly tensioned by having its ends connected to formed fingers 30 and 32 at the ends of plate 18. The spring 16 urges the resilient unit 14 radially inward so that a pair of flanges 34 extending from member 22 contact the bottom surface 36 of the plate 18 thereby normally positioning the top abutment surface 37 of resilient member 22 for supporting the type bars 38 at a predetermined level.

A form 40 (FIG. 3) extending along the entire forward edge of plate 18 provides rigidity to the guide support 12 and two lugs 42 are formed upwardly at each end of plate 18 to receive screws that rigidly mount the basket 10 to the typewriter basket carrier segment (not shown).

When a type bar 38 returns from the printing point to the basket 10, the force of the type b'ar slightly compresses the resilient member 22 upon contact whereupon the resilient unit 14 is moved radially outward against the tension of spring 16. The ability of the member 22 to return to its normal shape after compression is closely equalled by the amount of displacement of the unit 14 thereby resulting in a minimum rebound. Through experimentation, the amount of displacement was controlled through the use of the metal strip 24 located between member 22 and spring 16 and extending the entire length of the member. This provided the mass that is necessary to obtain the desired results while maintaining the compact construction.

It was also discovered by experimentation, after the mass of the metal strip 24 had been assembled to member 22, that in order to more closely equalize the degree of rebound of those type bars 38 located near the ends of the basket with those at the center, the mass was divided into two strips 24 substantially midway of its length. This changes the pivot point of resilient unit 14 from an end location to a central location, substantially at an innermost end 25 of metal strip 24. Dividing the metal strip substantially midway of the length of the basket reduces the lever arm distance approximately in half. By reducing the lever arm, the resistance of resilient unit 14 is increased by resilient member 22 absorbing more of the energy of the end type bar 38. The resilient unit 14 is thus displaced less which, in turn, has less rebound effect on the type bar. The energy of the type bars along the central portion of basket 10 is efiiciently absorbed with minimum rebound by the combination of the resilient unit 14 and spring 16.

Now it can be seen that by absorbing substantially all the energy of the returning type bar at the time of impact, the compact basket construction just described not only allows a minimum degree of rebound for all of the type bars 38, regardless of their basket position but, also provides a low silhouette type bar basket that is suitable for the powered typewriters with small basket area confines.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

1. A typewriter having a substantially semicircular basket for supporting a plurality of type bars thereon comprising:

(a) an arcuate resilient member for cushioning the im pact of the type bars when restored;

(b) an arcuate support for guiding said member for radial displacement relative thereto;

(c) a spring connected between the ends of said support for resiliently mounting said member to said support;

((1) a first arcuate element located between said spring and said member and extending substantially along one-half the length of said member and operable with said member for cushioning the impact of the type bars along said one-half the length of said member; and

(e) a second arcuate element located between said spring and said member and extending substantially along the remaining one-half the length of said member an operable with said member for cushioning the impact of the type bars along said remaining onehalf length of said member.

2. A typewriter having a substantially semicircular basket for supporting a plurality of type bars thereon comprising:

(a) an arcuate support having a slot extending along the length thereof;

(b) an arcuate resilient member having a flange portion for abutting against the outer circumference of said support and having an abutment portion extending through said slot, said abutment portion having a surface engageable by the type bars;

(c) a pair of arcuate metal strips each extending substantially along one-half the length of said member and adhered to the outer circumference of said flange; and

(d) a spring extending along said metal strip and having each end connected to a respective end of said support to assemble each of said metal strips and said member to said support for radial displacement relative thereto, said spring cooperating with said member and either one of said metal strips for cushioning the impact of the type bars and restoring the radial displacement of said member and either one of said metal strips caused by the impact of the type bars.

3. A typewriter having a substantially semicircular basket for supporting a plurality of type bars thereon comprising:

(a) an arcuate resilient member for cushioning the impact of the type bars when restored;

(d) a first arcuate element located between said spring and said member and having a first end adjacent one end of said member and a second end terminating at a point located substantially at the center of the length of said member, said first element being rigid relative to said member and operable to absorb the impact of the type bars near the first end of said first element by pivoting said member and said first element substantially about the second end of said element, and

(e) a second arcuate element located between said spring and said member at the opposite end of said member from said first element, said second element having a first end adjacent the opposite end of said member and a second end terminating adjacent the second end of said first element, said second element being rigid relative to said member and operable to absorb the impact of the type bars near the first end of said second element by pivoting said member and said second element substantially about the second end of said second element.

References Cited UNITED STATES PATENTS 2,176,123 10/1939 Denzer 19742 2,720,959 10/1955 Dodge et a]. l97--42 3,162,288 12/1964 Salto l9742 3,280,956 10/1966 Koenen 197-42 ROBERT E. PULFREY, Primary Examiner. E. S. BURR, Examiner,