US3602354A

US3602354A - Margin stop made of a synthetic material

Info

Publication number: US3602354A
Application number: US838149A
Authority: US
Inventors: Lolf Theilen
Original assignee: Olympia Werke AG
Current assignee: Olympia Werke AG
Priority date: 1968-07-11
Filing date: 1969-07-01
Publication date: 1971-08-31
Anticipated expiration: 1988-08-31

Abstract

A margin stop for stopping the paper carriage of a typewriter in an end position, is constructed as an integral piece of a synthetic material including a tooth, and a spring tongue engaging a rackbar and biassing the tooth to engage the rackbar.

Description

United States Patent Inventor Roll Theiien Wilhelmshaven, Germany Appl. No. 838,149 Filed July 1, 1969 Patented Aug. 31, 1971 Assignee Olympia Werke Aktiengesellschaft Wilhelmshaven, Germany Priority July 11, 1968 Germany 0 10 096 MARGIN STOP MADE OF A SYNTHETIC MATERIAL 6 Claims, 3 Drawing Figs.

U.S. Cl 197/70 Int. Cl B4lj 21/04 Field of Search 197/63, 70, 151

References Cited UNITED STATES PATENTS 472,696 4/1892 Blickensderfer 197/70 X 9/1903 Myers 197/70 Holden 4.

Dowd

Garbell Harmon Dobson Sharpe Suif Mimlitch FOREIGN PATENTS Germany Great Britain Great Britain ltaly Primary Examiner-Ernest T. Wright, Jr. Attorney-Michael S. Striker ABSTRACT: A margin stop for stopping the paper carriage of a typewriter in an end position, is constructed as an integral piece of a synthetic material including a tooth, and a spring tongue engaging a rackbar and biassing the tooth to engage the rackbar.

MARGIN STOP MADE OF A SYNTHETIC MATERIAL BACKGROUND OF THEINVENTION Conventional typewriters have a rack bar on which two margin stops are mounted, whose position can be adjusted to determine the end positions of the paper carriage, and correspondingly the length of a typed line.

Margin stops in accordance with the prior art are constructed of a great number of small parts which are difficult to assemble, and expensive to manufacture.

. SUMMARY OF THE INVENTION It is one object of the invention to provide an inexpensive margin stop of extremely simple construction which requires practically no assembly operations.

Another object of the invention is to provide a margin stop which produces little noise upon the impact of the returned paper carriage.

With these objects in view, the present invention is concerned with a margin stop which comprises an integral piece, preferably consisting of a synthetic material.

A margin stop according to a preferred embodiment of the invention has spaced front and rear portions located on opposite sides of a rack bar, and top and bottom portions connecting the front and rear portions above and below the rack bar, respectively. The bottom portion has an upward projecting tooth portion and the top portion has a downward projecting resilient portion abutting the top surface of the rack bar for raising the bottom portion and the tooth portion to a locked position in which the tooth portion engages a recess in the rack bar. The top portion has on top a finger engaging surface so that finger pressure on the same deforms the resilient portion and lowers the bottom portion with the locking tooth portion to a position in which the same releases the recess in the rack bar so that the margin stop can slide along the same.

In a modified embodiment, a metal spring is used instead of the resilient portion of synthetic material, and a metal tooth is inserted into the bottom portion.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional ob jects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary perspective front view illustrating a margin stop according to one embodiment of the invention;

FIG. 2 is a fragmentary perspective rear view illustrating the margin stop of FIG. I; and

FIG. 3 is a fragmentary front view illustrating a modified margin stop in accordance with the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An integral piece of synthetic material 1 forming a margin stop is mounted on a rack bar 7 having on its bottom face teeth 7a. The term integral piece of synthetic material" is used to denote an integrally molded piece of synthetic material. A rear portion 4 in the form of a flat wall, and a front portion including two front portion parts 5 and 6, and a rectangular cutout 8 between the same, are located on opposite sides of rack bar 7 slidably engaging the same. A top portion 2 is located above the rack bar 7 spaced from the same, and a bottom portion 3 is located below the rack bar 7. Top portion 2 and bottom portion 3 connect front portion 5, 6 and rear portion 4. Top and bottom portions 2 and 3 have inner surfaces bounding cutout 8 on top and bottom.

A resilient portion 9 in the form of an elongated tongue having a projection 9a at one end, and being integrally connected with top portion 2 at the other end, resiliently abuts with por tion 9a on the upper surface of rackbar 7 to hold the integral piece 1 in the illustrated position in which a tooth portion 10 at one end of bottom portion 3 engages a recess between teeth 7a of rack bar 7. A stop 11 cooperating with the corresponding part of the paper carriage, and a bell actuating projection 12 are provided at the ends of bottom portion 3, integral with the same. i j' The top portion 2 has an upwardly slanted curved finger-engaging surface 14 ending in a high surface 13, and located above the tooth portion 10. As best seen in FIG. 2, a curved fulcrum portion 16 is provided at the other-end of bottom portion 3 and is in contact with the teeth 7a of rack bar 7 due to the action of the resilient portion 9 which holds the integral piece 1 in a raised position. At the corresponding end of top portion 2, a downwardly projecting curved guide portion 15 is provided which abuts the top surface of rack bar 7. The top portion 2 has

end portions

15 and 2a, and the bottom portion 3 has end portions 16 and 10a connecting the front portions 5, 6 with the centrally located rear portion 4. Piece 1 has one end where fulcrum portion 16 and guide portion 15, and another end where tooth portion 10 and the end 9a of the resilient portion 9 are located.

Due to the fact that

curved portions

15 and 16 slidingly engage the top' and bottom surfaces of rack bar 7, the integral piece 1 is guided on the rack bar 7, but sliding movement is prevented as long as tooth portion 10 engages a recess of the rack bar 7 due -to the action of resilient portion 9. The horizontal bottom surface 17 of end portion 2a of top portion 2 is spaced the distance a from the top surface of rack bar 7, as shown in FIG. 1.

The integral piece 1 serves as a margin stop, and when; the position of the integral piece 1 on the rack bar 7 is to be changed, finger pressure is applied in the direction A to the finger engaging surface 14. Due to the slant of the finger engaging surface 14, the applied pressure has two components, namely one component in longitudinal direction of the rack bar 7, and another component which is downwardly directed and causes compression of the resilient portion 9, while the integral piece 1 performs a pivotal movement about the fulcrum portion 16 to a lower position in which the end portion 10a and the tooth 10 thereon is lowered so that the tooth I0 is retracted from the respective engaged recess permitting sliding of the integral piece 1 along the rack bar 7 due to continued finger pressure. When the finger engaging surface portion 14 is released, the resilient portion 9 raises portion 10a while the integral piece 1 turns again about the fulcrum portion 16 until tooth 10 engages another recess in the rack bar 7. The curved surface 15a of the guide portion 15 permits the angular displacement of the integral piece 1 while guide portion 15 remains in contact with the upper surface of rack bar 7. An index mark 18 is provided which cooperates with a graduated scale, not shown, by which the position of the integral piece 1 on the rack bar 7 is numerically indicated.

In the modified embodiment of FIG. 3, the integral piece 1', which consists of a synthetic plastic material, has portions 2' to 6', and 11' to 16' corresponding to portions 2 to 6, and II to 16 described with reference to FIGS. 1 and 2. However, instead of the integral resilient portion 9, a leaf spring 9' is provided which has a curved center portion abutting the bottom surface 17' of top portion 2, and two curved end portions 90 and 9b which resiliently abut the top surface of rack bar 7. The curved end portion 9b matches the contour of the curved guide portion 15, and the end portion 9a has a part engaging the end face of end portion 2a of top portion 2' so that the spring 9 is secured against longitudinal movement along the rack bar 7. Since the tooth 10 of the embodiment of FIGS. 1 and 2 is subjected to great wear, it is replaced by a metal tooth 10 inserted into a slot 10" in the end portion 10a of bottom portion 3.

When pressure is exerted on the finger engaging surface 14, spring 9' is compressed, the piece 1' turns about the curved surface of fulcrum portion 16 in clockwise direction as viewed in FIG. 3, until the surface 17' abuts the top surface of rack bar 7 so that tooth is retracted from the respective recess in rack bar 7, permitting longitudinal sliding of the margin stop 1', 9', 10' by finger pressure on surface 14'.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of margin stops differing from the types described above.

While the invention has been illustrated and described as embodied in a margin stop consisting of an integral piece of a synthetic plastic material, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

lclaim:

l. Margin stop comprising an integrally molded piece of a synthetic material having spaced front and rear portions with confronting faces for slidingly engaging the sides of a rack bar, and top and bottom portions connecting said front and rear portions above and below said rack bar so that said piece surrounds the rack bar, said bottom portion having an upward projecting tooth portion, and said top portion including a downward projecting resilient portion for engaging the top of the rack bar so that the piece is raised whereby said tooth portion engages the rack bar, said top portion having on top a finger engaging surface so that pressure on said finger engaging surface moves said piece downward whereby said tooth portion is lowered to a position disengaged from said rack bar.

2. Margin stop comprising an integrally molded piece of a synthetic material having spaced front and rear portions with confronting faces for slidingly engaging the sides of a rack bar, and top and bottom portions connecting said front and rear portions above and below said rack bar so that said piece surrounds the rack bar and has two ends spaced in one direction along the rack bar, said bottom portion having at one of said ends an upward projecting rounded fulcrum portion, and at the other of said ends an upward projecting tooth portion, said top portion having at said one end opposite said fulcrum portion a rounded downward projecting guide portion for sliding on the top of said rack bar, said top portion including an elongated resilient portion connected at said one end with the bottom of said top portion and projecting in said onedirection toward said other end of said piece and also downward for slidingly engaging the top of the rack bar in the regionof said other end so that said other end is raised whereby said tooth portion engages the rack bar, said top portion having on top a finger engaging surface located at said other end so that downward finger pressure on said finger engaging surface deforms said resilient portion and turns said piece about said fulcrum portion and guide portion whereby said tooth portion is lowered to a position disengaged from the rack bar.

3. Margin stop as claimed in claim 12 wherein said finger engaging surface is slanted upward toward said one end so that the margin stop can be moved along said rack bar by finger pressure in said one direction after downward finger pressure has disengaged said tooth portion from the rack bar.

4. Margin stop as claimed in claim 2 wherein said front portion has two front portion parts and a cutout between said two front portion parts; and wherein said rear portion is located opposite said cutout; and wherein said top and bottom portions have end parts integrally connected with said two front portion parts and central parts integrally connected with said rear portion.

5. Margin stop as claimed in claim 4 wherein one of said end parts of said bottom portion includes said tooth portion, and wherein the other of said end parts of said bottom portion has said fulcrum portion provided with a curved fulcrum surface.

6. Margin stop as claimed in claim 2 wherein said bottom portion has an integral stop projection and an integral bell actuating projection spaced in said one direction along the rack bar.

Claims

1. Margin stop comprising an integrally molded piece of a synthetic material having spaced front and rear portions with confronting faces for slidingly engaging the sides of a rack bar, and top and bottom portions connecting said front and rear portions above and below said rack bar so that said piece surrounds the rack bar, said bottom portion having an upward projecting tooth portion, and said top portion including a downward projecting resilient portion for engaging the top of the rack bar so that the piece is raised whereby said tooth portion engages the rack bar, said top portion having on top a finger engaging surface so that pressure on said finger engaging surface moves said piece downward whereby said tooth portion is lowered to a position disengaged from said rack bar.

2. Margin stop comprising an integrally molded piece of a synthetic material having spaced front and rear portions with confronting faces for slidingly engaging the sides of a rack bar, and top and bottom portions connecting said front and rear portions above and below said rack bar so that said piece surrounds the rack bar and has two ends spaced in one direction along the rack bar, said bottom portion having at one of said ends an upward projecting rounded fulcrum portion, and at the other of said ends an upward projecting tooth portion, said top portion having at said one end opposite said fulcrum portion a rounded downward projecting guide portion for sliding on the top of said rack bar, said top portion including an elongated resilient portion connected at said one end with the bottom of said top portion and projecting in said one direction toward said other end of said piece and also downward for slidingly engaging the top of the rack bar in the region of said other end so that said other end is raised whEreby said tooth portion engages the rack bar, said top portion having on top a finger engaging surface located at said other end so that downward finger pressure on said finger engaging surface deforms said resilient portion and turns said piece about said fulcrum portion and guide portion whereby said tooth portion is lowered to a position disengaged from the rack bar.