US 3921321 A
A convertible sign in which one or a plurality of rotatable prismatic signs is arranged to be rotated through fixed angles by a Maltese cross and gear arrangement and to be locked in a new position by a lock fitted between arms of the Maltese cross. A plurality of signs can be fixed to rotate together. A track-and-carriage mechanism coupled with an eccentric is used in one embodiment to rotate and lock the signs.
Description (OCR text may contain errors)
United States Patent Weisskopf Nov. 25, 1975 l l CONVERTIBLE SIGN 1,077,885 11/1913 La Pearl 40 777 u 7 1,650,059 ll/l927 Bartolomucci 40/77]  g i x phhppbburg 2,277,323 3/1942 Hjermstad et al. 40 777 er y F E AT  Assignee: The Firm of Georg Merkel, 174 J I ZB Z S 7 n1 e mg om g i l to Jolgnn Hawner 244,434 3/1912 Germany 40/777 C we many 536,329 2/1922 France 40 777  Filed: Jan. 21, 1974 Primary Examiner.lohn H. Wolff 21 A l. 4 ,8 I 1 pp NO 34 99 Attorney, Agent, or FirmL1ttlepage, Quamtance,
Murphy & Dobyns  Foreign Application Priority Data Jan. 31, 1973 Germany 1. 2304570 57 ABSTRACT Sept. 26, 1973 Germany 2348374 A convernble s1gn 1n wh1ch oneor a plurahty of rotat  U.S. Cl. 40/33- 40/77.7 able prismatic signs is arranged to be rotated through 51 1m.c1. G0 9F 11/00 fixed angles by a Maltese and gear arrangement 51; Field 01 Search 40/774 77.6 77.7 77.8 and to be locked in a new Position by a lock fitted 46/77 30 5 tween arms of the Maltese cross. A plurality of signs can be fixed to rotate together. A track-and-carriage  References Cited mechanism coupled with an eccentric is used in one UNITED STATES PATENTS 4/1913 Goldstein 40/77.7
embodiment to rotate and lock the signs.
1" Claim, 6 Drawing Figures Sheet 1 of 4 3,921,321
US. Patent Nov. 25, 1975 US. Patent Nov. 25, 1975 Sheet2of4 3,921,321
US. Patent Nov. 25, 1975 Sheet4of4 3,921,321
CONVERTIBLE SIGN BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a convertible sign together with a device for revolving the sign through a predetermined angle. See Class 40 Subclass 77.4 and 77.8 and Class 74 Subclass 4.36.
2. Description of the Prior Art There are several known kinds of convertible signs, for example those arrow-signs which periodically guide the arriving traffic in two or more different directions. Such a sign has to be turned around a horizontal axis through a predetermined angle. These signs can be in several forms, such as right circular cylinders or prismatic cylinders. The most widespread kind of convertible sign, however, consists of a box which includes a window, in which a part of a roll shutter or the surface of a prismatic roll (i.e. an equilateral right prismatic cylinder, which is an elongated prismatic element) is visible. If the sign is to be changed, the axis of the shutter of the prismatic roll is turned.
For smooth functioning of the convertible sign, it is absolutely necessary that it work exactly and that the revolving movement can be repeated in exactly the same way. One small mistake in the adjustment may be compounded by a sequence of repeated operations, and may finally lead to wrong information. This may happen especially in case the changing of the sign cannot be watched while it is manually released.
An exact adjustment could be performed if a step motor were used. However, if this motor were directly connected, the motor would have to be powerful, which would mean that it would be heavy and costly. When, however, a motor is used together with a transmission, thus requiring the motor to make several revolutions until it is adjusted again, then additional means are needed in order to slow down and stop the system very exactly. For this purpose, a detent together with a cam disk can be used. Since this mechanical device is used to compensate for mistakes in adjustment, it is subject to strong stress. Furthermore, the changing is carried out very slowly because of the transmission.
In convertible signs, in which the signs are mounted on a prismatic roll which is placed in a box, this roll is sealed within the window against the housing by a rubber profile. Since the edges of the roll, while being turned, do not move in a straight line but in a circular one, this seal quickly wears out when the signs are changed, i.e. when the roll is turned.
SUMMARY OF THE INVENTION The present invention provides a mechanism which guarantees exact adjustment of the sign together with smooth stopping, even when the motor is coming to a halt. The mechanism has a high sign changing speed. The invention provides a convertible roll sign which can be changed very smoothly and in which the seal is not subject to major wear out.
A Maltese cross is used in obtaining an exact, turning angle. The Maltese cross additionally contains a gear transmission for obtaining the desired angle. Though Maltese crosses are well known in several technical fields, these crosses have not yet been used for changing prismatic signs, although these signs have already existed for decades. These Maltese crosses are not only built like crosses, which means they have four beams, but are also built with three, five or more beams. These Maltese crosses, especially those with more than four beams, are not stable enough for many purposes unless stabilizing structure is added. If a Maltese cross is used for a convertible sign, there is the disadvantage that for each sign requiring a different turning angle, different Maltese crosses must be produced and kept in stock. In using a gear transmission, this disadvantage can be overcome. However, a gear transmission is not necessary, especially if a fixed type of sign allows standardization.
In order to save the seal profile on the window'of the box, the roll is mounted on a carriage and a device, is installed for a periodic return movement of the carriage, which works together with the device for the stepwise turning of the roll. This device for the periodic return movement of the carriage contains an eccentric which is in an abutting relationship to the housing of the convertible sign.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a convertible sign together with a Maltese cross.
FIG. 2 is a view of a convertible sign which consist of several triangular rolls together with a Maltese cross.
FIG. 3 is a side view of a roll of a convertible sign together with the carriage.
FIG. 4 is a front view of the roll shown in FIG. 3.
FIG. 5 is a view like FIG. 3, with the front side wall of the carriage removed.
FIG. 6 is a view of the roll according to FIG. 5 at th moment when the sign is changed.
DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 of the drawings shows a first embodiment of the invention. A gear 4 is mounted on the axle or axis of the Maltese cross 1 outside the plane of a lock 2 and a driver 3. Gear 4 meshes together with gear 5 which is disposed on the axle of a turning arrow 6, thereby forming a connection means with a transmission ratio is 1:2 for transmitting torque from gear 4 to gear 5. Thus, if the Maltese cross is turned by the arrow will be turned by 45.
The embodiment shown in FIG. 2 is a convertible sign which consists of triangular rolls 6a-6e which are connected to a guiding pole 8 by levers or radial arms 7a to 7e, thereby interconnecting the radial arms to compel the signs to turn in unison. On the front side of one of the triangular rolls (roll 6c in the drawings) is mounted gear 5, which is coaxially disposed with the axle on which the lever 7c is mounted. Between the gears 4 and 5, the preferred transmission ratio is 4:3.
If a four-sided roll is used together with the fourbeam Maltese cross there will be a transmission ratio of 1:1. In this case the gear transmission may be omitted and the Maltese cross may be mounted directly to the axle of the sign.
Such an embodiment is shown together with the foursided roll in FIGS. 3 to 6. In a housing 9, a carriage 11 is mounted on a track 10. The housing consists of a frame 12 together with sidewalls 13 and a connection rod 14. Track 10 has a U-shaped cross section and carries wheels 15 of carriage 11. In frame 12 is mounted an axle 16 which carries the prismatic roll 6.
. On axle 16 is further mounted a wing (i.e., yoke) 17, the other end of which is connected to a slide 18, which is mounted on track 10. An eccentric or eccentric cam 19 meshes with a longitudinal opening in the wing 17. The eccentric 19 is mounted on an axle 20, on which the driver 3, the lock 2 for the Maltese cross and a chain pulley 21 are also mounted. Chain pulley 21 is connected by a chain 22 to a motor 23, which may be an electric motor or other motive power means. The motor 23 is mounted on the back of the carriage 1 1. On the front side of roll 6 is mounted a Maltese cross which works together with the driver 3. On the front of the housing there is, relating to the sign 24 of roll 1, an opening 25, which shows a seal profile 26.
On both ends of the roll 6 there are mounted mechanisms as previously described, which are built up ina mirror relationship to each other. Both mechanisms are driven by a chain 22 from the common motor 23.
If the sign of roll 6 is set in its normal position, then it is positioned within the'opening 25 of the housing 9 and is sealed on its edges by seal 26. The roll 6 islocked in its position by the lock 2 (FIG. 1f the sign is to be changed the motor 23 is switched on. It drives the chain 22 and the pulley 21 together with the connected driver 3 and the eccentric 19. The wing 17 is moved by the turning of the eccentric 19. Since the wing 17 is firmly connected with the slide 18', which by itself is firmly connected to track and to housing 9, the axle 16 together with carriage l1 and roll 6 is pressed in the direction of the central axle of the housing 9. As soon as the eccentric 19 and driver 3 have been turned by 135, driver 3 enters the corresponding slit of the Maltese cross 1 and starts to turn roll 6. The turning movement is completed after afurther .90., Subsequently the roll is locked by the lock 2 in its position and the carriage is pushed again by eccentric 19 towards opening 25. If the eccentric has been turned by 180, one whole operation of the movement of carriage v11 has been completed. r
The result is an operation in which roll 6 has been retracted from opening 25, turned round and, pushed back again. Only one quarter of the total time required is spent in turning roll 6, whereby the roll is accelerated from a standstill and subsequently slows down again according to a sine-shaped line, whereby a'very smooth turning movement is obtained. i
It is obvious that the embodiment shown for the foursided roll can also be used for a roll with a different prismatic form when a gear transmission is added. And, too, there is the possibility of mounting several rolls on one carriage. Thus there are forms built up which represent combinations of the embodiment shown in the FIGS. 3 to 6 and the embodiment shown in FIG. 1 and- /or FIG. 2.
1.; A convertible sign system comprising:
A. an elongated prismatic element (6) comprising a plurality of flat faces adapted to carry indicia thereon, the prismatic element having a longitudinal axle (16) about which the prismatic element may be rotated,
B. a Maltese cross (1) fixedly mounted on said longitudinal axle, whereby the prismatic element rotates when the Maltese cross rotates and remains fixed when the Maltese cross does not rotate,
C. a housing (9) comprising an opening (25) for display through said opening of a selected one of the plurality of faces,
D. a track means (10) mounted in the housing,
E. a carriage l 1) situated on and slideable along the track means,
F. motive power means (23),
G. driver means (3) powered by the motive power means (23) for rotating the Maltese cross, and therefore rotating the prismatic element, about the longitudinal axle, I
H. a yoke element (17) comprising two ends and a central portion having a longitudinal opening therein,
I. means for pivotally mounting one end of the yoke element (17 on said longitudinalaxle- (16),
J. a slide element (18) affixed to the other end of the yoke element (17), the slide element being slidably mounted on the track means (10), and
K. an eccentric (19) powered by'the motive power means (23) and connected to be operated simultaneously with the driver means (3), the eccentric being fitted into the longitudinal opening in the central portion of the yoke element (17), whereby, when the motive power means is operated to cause the driver means to engage the Maltese cross and thereby to rotate the prismatic element to convert the sign system by displaying a new face of the prismatic element, the eccentric simultaneously engages the longitudinal opening of the yoke, thereby'causing the yoke to pull the carriage and the prismatic element back along the track means from the housing opening.