GLOSSARY & CONCEPTS
We named our product UDEG – uplifting doubleframe eyeglasses.
The fixed frame could be upper-rimmed (like most glasses) or lower-rimmed (applicable especially for presbyopic small reading lenses) – this depends on type and application of model (see photos below).
The four-bar linkage of the moving frame with lenses is required to ensure vertical positioning of lenses in the upper position to avoid contact of lenses with forehead.
Lenses of the moving frame and the fixed frame superimpose in certain cases, this gives additional benefits of combining two functions (i.e. sunglasses and myopic lenses).
I. QUESTIONS AND DOUBTS WE FACED
Market entry. Some market participants point out that UDEG might be harder to sell than to manufacture as they are a new type of eyewear. This could be true, but we must bear in mind that there is a great number of standard identical models of eyeglasses on the market; thousands of designers offer almost the same options, and trends in fashion repeat in time (aviator, cat eye, etc.). Many people have dozens of glasses in their collections, so they will gladly buy one extra unusual model, especially since no one else has similar product yet. The trick is to ensure high-quality production and provide such glasses with proper advertising. Manufacturing technology of uplifting eyewear is no more difficult than of the standard one. Reliability is proved by our two year wearing experience (see our Instagram videos).
Weight. Titanium doubleframe eyeglasses are lighter than ordinary models made of steel. In case of frame manufacturing from one thin sheet of metal, assuming only cutting and polishing, without using milling and welding, frame weight would be very modest. Modern anodizing methods allow titanium to be coated in any color. Rhodium and gold plating is optional. Production costs Such titanium frames would have reasonable .
II. DESIGN WISHES AND RESTRICTIONS
Glasses for myopes are the easiest to design. People who have been wearing minus glasses throughout their lives face age presbyopia symptoms that force them to take off glasses in order to read. In such cases there is no need to lift the moving frame to the maximum, so it would be just enough to slightly raise the frame with myopic lenses. In all other types of UDEG one has to lift the moving lenses completely, so that their lower segment does not obstruct the field of view since in most cases users raise their eyes when looking into the distance. The inner segments of the lenses (located closest to the bridge) rise a little higher that outer lateral segments of lenses (due to the "around the ball” movement caused by four-linkage bar mechanism). One of designer’s major task would be to elegantly cut these outer lower areas of the uplifting frame/lenses so that they do not abstract the view when lifted and would look natural in the lower position of the moving frame. The bridge between lenses of the uplifting frame must be bent outward and upward. Outward – so that it doesn’t cling to the fixed frame in the lower position; upwards – so that when the moving frame would be lifted to the full, the bridge would come in contact with forehead and not the lenses.
The most difficult in design, as we see it, would be the version of UDEG with two pairs of full size lenses (i.e., myopic lenses for constant wear on fixed frame, and sun lenses on the movable frame). Therefore, we believe it is safer to start with design of men's myopic glasses (only one pair of lenses on the uplifting frame) with limited uplifting movement. We think so because men are not so demanding on certain design aspects and could easier accept the cut off of the upper outer edges of lenses, while women generally prefer "cat's eye" glasses with initially high outer edges of frame/lenses, that looks good in the lower position of moving frame, but would look too protruded when lifting the frame.
In accordance with said above, we would suggest to consider following possible options for designing and production of first industrial prototypes of UDEGs:
1. Men’s eyewear for myopes with one pair of lenses on the uplifting frame (progressive lenses could be used as well).
2. Lady’s eyewear for myopes with one pair of lenses on the uplifting frame (progressive lenses could be used as well).
3. Men's sunglasses with one pair of lenses on the uplifting frame.
4. Lady’s sunglasses with one pair of lenses on the uplifting frame.
5. Men’s presbyopic UDEG with small reading lenses on the fixed frame and a pair of presbyopic lenses on the moving frame.
6. Lady’s presbyopic UDEG with lower-rimmed fixed frame with small reading lenses and a pair of full-sized presbyopic lenses on the moving frame.
7. Lady's glasses with two pairs of lenses: dioptric for constant wear on the fixed frame and sunscreen lenses on the moving frame.
8. Men's glasses with two pairs of lenses: dioptric for constant wear on the fixed frame and sunscreen lenses on the moving frame.
The toughest technological challenge is to make UDEG with one or two levers of the four-bar linkage mechanism as springs, full lowering of the frame would be possible when these springs become bent. Lifting of the frame would be realized by these spring levers seeking to straighten. Such spring solution would require fixation of the movable frame in the lower position. This fixation is possible with the latch of the movable frame on the fixed one in the area of the bridge/nose pads. We could obtain light construction of glasses if the latch would be light and easy-to-manage.
III. SPECIAL REQUIREMENTS FOR MANUFACTURING OF PROTOTYPES OF UPLIFTING DOUBLEFRAME EYEGLASSES
The uplifting doubleframe eyeglasses consist of two frames, fixed one and a movable (uplifting) one that are interconnected on right and left sides by four-bar linkage mechanism. Temples and nosepads are attached to the fixed frame.
The four-bar linkage mechanism is there to ensure vertical positioning of lenses in the upper position in order to avoid contact of lenses with forehead.
Concept is shown below:
We are looking for specialists to design and produce the industrial prototype for its subsequent mass production. This prototype should consist of sunglass lenses on the moving frame with no lenses on the fixed frame (the fixed frame should consist of only top rim of front eyepieces). The uplifting frame with sun lenses should cover all the construction to make it look as ordinary sunglasses when the uplifting frame is down. Such simple construction would allow to study all issues of the uplifting mechanism and develop the best solution for robust four-bar linkage supported by proper frame endpieces and wide temples. The design should be chosen from popular casual sunglasses shapes (not sport!) with relatively flat bottom line of lenses/rims (Aviator or round not suitable).
Samples are shown below:
Next industrial prototype would be the uplifting frame model with same sunglass lenses and the fixed frame fully ready for mounting of second pair of lenses (for example, myopia dioptric) with a nylon cord (eyewire) if such lenses would be required by user. If you consider development of such industrial prototype to be as simple as one pair of sunglass lenses (first model), we are ready to discuss it.
Following conditions have to be met:
1. The four bars attachment points should be located on the endpieces of fixed frame as high as possible, and the attachment points on the moving frame endpieces should be located as low as possible. The distance between the upper and lower hinges of four-bars linkage on the fixed frame should be approximately 4-7mm. Distance between upper and lower hinges on the movable frame should be around 10-15 mm. Hinges are not necessarily located on the same vertical plane. Length of levers – from 20 to 50 mm. It is possible to make them shorter, however, the shorter the levers – the greater the angle, respectively, the greater the misalignment of the frame. Long levers are most appropriate, but for this larger bend angle of the fixed frame has to be achieved, so that hinges of levers on the fixed frame would be closer to the temporal bone. Large bend angle of the frame does not necessarily imply that lenses too would have large angle with respect to each other. However, aspheric lenses are preferable. This doesn’t sound complicated to achieve, however upper and lower positions of the moving frame have to be coordinated with fixed frame dimensions, especially when the latter would bear the second set of lenses.
2. The fixed frame should be curved around the face like most models of sports eyeglasses are. The moving frame should be curved or almost straight. Construction of the fixed frame should be robust to avoid deforming.
3. Once in upper position, the movable frame should be fixed to avoid sliding down during moving and walking of wearer. This should not be achieved by increasing friction of the four-bar linkage mechanism itself as such friction would prevent from frame lifting with just one hand which is an important requirement.
4. In order to avoid distortion of the frame when lifting the moving frame, it is necessary to make frames with increased torsional and bending stiffness, moreover, upper and lower bars may lay in different planes to form a girder to add strength to the construction. For instance, one pair of bars could be secured inside the fixed frame or temples and the other pair – on the outside. In such case bars might be curved to allow elongated sliding move of the lifting frame. In any case it is important to attain possibility to uplift and downslide the moving frame with just one hand.
5. In sport glasses flexes are usually not used, fixing on the head is ensured by tension of the curved frame. In case of UDEGs, bending of the fixed frame leads to excessive and disproportionate moving of the uplifting frame forward, which is undesirable, therefore, it is necessary to make the fixed frame rigid and inflexible while fixing on the head by temples could be reached either by flexes on temples, or by springiness of the fixed frame in the area between hinges of the levers and the hinge of temples.
Additional focus should be kept on following aspects:
- the lower edge of the uplifting frame should esthetically accord with the fixed frame;
- please aim to nicely match upper rim lines of both moving and fixed frames when the uplifting frame is in lower position;
- please consider possibility to cut off the upper outer corners of the movable frame (and lenses as shown on picture) as they protrude substantially when lifted up.
We are ready to answer all your questions and provide extra information on UDEGs. In case you would be interested in designing and manufacturing the industrial prototype of UDEG, we are ready to start the process as soon as possible.
Thank you in advance.
NeckTec eyewear team.