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Dating back to some 3000+ years B.C., Scissors and shears have been generally of the same design, which incorporates two pieces as similarly shaped blades joined at a pivotal point so that the edges slide by one another. The disadvantages to this design result in difficulty of use by those with manual
limitations such as carpal tunnel syndrome, arthritis, repetitive stress injury, and fatigue from prolonged use.
Various attmepts have been made to improve the design and efficiency of the conventional scissor, with limited success.
I propose an improved scissor which avoids the discomforting thumb-to-finger squeezing action required by most of the generally known scissor designs, and provides additional stability over conventional construction.
Have you ever tired to cut a pice of cardboard with conventional scissors? If you have, you have had the desire to remove your hand from the plane in which you are attempting to cut.
I propose a scissor that has handles upright at a slightly (ergonomic) acute forward angle to the cutting plane. The construction would be such that a squeezing motion similar to a gripping action would actuate the scissor, allowing that even those who are missing certain digits (fingers or even a thumb) would be able to use them.
The means by which these scissors operate would be via a four-bar lever system, which would allow the lower blade to remain radially stationary to the cutting plane, enhancing not only ergonomics, but the shearing of heavy and sheer materials as well.
Mechanical advantage would be nearly infinitely variable with lever configuration and blade length (note provision for spring-biased open positioning), and cutting would be achieved with more ease and comfort than current designs. (patent pending, licensing and further information available)
What I really mean...
http://hometown.aol...homepage/photo.html
This should help clear things up a bit [X2Entendre, Oct 04 2004, last modified Oct 05 2004]
Example of a four-bar actuated scissor in conventional form
http://www.swissors.com/
Similar in configuration to scissors originally patented in Sept, 1953. (link to which is not available) [X2Entendre, Oct 04 2004, last modified Oct 05 2004]
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[UnaBubba], there was no mention of power tools made here, but thank you. |
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The mechanical advantage is intriguing, but I'm having trouble visualizing the //four-bar lever system//. I can't get around the problem of having to move the handles a foot to move the blades an inch. |
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[Don Quixote], your link is totally irrelevant. Those are offset-handled shears, whose handles are not even remotely at an acute forward angle to the cutting plane. I suspect that you're not reading my idea as I've envisioned it. |
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You're right, I missed the implications of the *acute* part of your idea. Link removed and previous anno updated. Thanks to [waugs] for pointing out that the hinge goes behind the hand. |
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I tried to draw an example, but I couldn't work out the mechanical link (hinge? gearbox?) between the handles and the blades. |
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Thank you [Don] and [Waugs] for making it obvious that I need to back this up with an illustration. [link] By the way, [Bristolz], your concept is actually not too far off (and gave me a bit of a chuckle), but a bit lacking in ergonomics. <G> |
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Yeah, well I suck at ergonomics. |
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No problem, [Bristolz], I liked your link, you should have left it up ;) C'mon, I think I could actually sell this to one out of every 400 people (in the US alone) annually at $15 USD a pop, wouldn't that make me a load of cash by the time the utility patent expires? <G> |
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Well, it made no sense linked _after_ your correct drawing. You beat me by a few seconds. ;-) |
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I think it's probably worth pursuing. Do you think it's harder to guide along a path with your hand in that upright position? |
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I still see no croissants... |
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[bristolz] Ok, this product is partially developed and patent pending, and I agree that it may be a bad idea to place a (semi) developed product here, but I'm looking for 'red team' feedback also. I've placed a prototype in the hands of quilters and sewing hobbyists, all of whom have regarded it with great enthusiasm. Their most common remarks include that it cuts sheer fabrics with exceptional ease, as the lower blade does not disturb the fabric as conventional shears do, as well as having the hand removed from the cutting plane. Pick this thing apart and give me all the feedback you can think of... that's why it's here! |
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Neutral vote. I focused on the problem of cutting //heavy// materials like //cardboard//. From that perspective, I like the idea, but I'm not convinced that the complex mechanical design is better than the simple lever arm solution of long-handled shears (tin snips, for example). [bristolz] makes a good point by asking about guiding when cutting. And you'd probably need to shape the blades to keep the hinge mechanism above the cutting plane, otherwise the hinge might bind in the cut. |
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[Don] the hinge doesn't seem to be a problem as the movable blade is on the same side as the lever mechanism, which puts the lever above the material that is being pushed down during the cutting process, yes... I thought of that. On a more pleasant note, I'm glad to see some real discussion on a real idea in the halfbakery... It's been SO long... thanks! |
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Croissant. Add a footpedal (like on old sewing machines) for hands-free scissors. |
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Dr Bob : "old" sewing machines?! you are mistaken! the newest of the new come with pedals; quite the most necessary thing to have. |
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Rather than bordering on advertising, I'd define it as last minute input from trustworthy 'bakers - perhaps one could throw in a useful suggestion for further prototype development. |
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(+) Looking at the link, I wondered if a thin triangular shaped fin, with its widest end at the rear, could be incorporated as a base for the bottom shear. This would keep the scissors upright when cutting and allow them to stay that way if you had to unexpectedly leave your cutting for a moment. |
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It seems that cutting heavy materials up close to the pivot might force your hand fairly wide, not much leverage. (Not worse than normal scissors, though.) Just a thought that an adjustable joint, like on a pair of slip-joint pliers, might make an easier go of thick stuff. (Adjustment would change the active length of the short link marked in green.) |
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5-degree offset shears with a spring return solve this nicely. |
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I like it, if for no reason other than that it shouldn't need a separate model for left-handers. |
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I like the idea alot, its simplicity and lateral thought- but I don't think I'd prefer it to a regular scissor: This design may mean that the handle (and operating fist) are blocking the line of sight. I assume that it doesn't cos no-one else has mentioned it. (+) |
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[toejam], most of my patented or patent-pending items have not and will not be disclosed here, but this one is more of a 'mass market' item and, I felt that the œB would be an excellent place to get some honest opinions.
/Rather than bordering on advertising, I'd define it as last minute input from trustworthy 'bakers - perhaps one could throw in a useful suggestion for further prototype development./
Well put, [thumbwax], this is exactly my intention in placing this here. I had considered that there are several 'bakers here who would give this a thorough consideration and give honest remarks, which I value.
[UnaBubba], there has been interest in the design, but it is radically different than what scissor companies currently produce, which seems to discomfort them a bit in regards to a possible uncertainty in marketability. On the other hand, I have placed this revision of the design in the hands of several people who have all been no less than enthusiastic with its performance, so the 'uncertainty in marketability' isn't daunting to me.
I am researching the possibility of this product's qualifying for government funding for development, as it is a product that could benefit the manually impaired, but in the event that this doesn't "pan out", I would be very interested in pursuing "seed capital" to finalize development and begin manufacturing this product on my own. If you know of funding prospects, I would be happy to discuss this further.
Thank you to all who have given feedback on this idea. |
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How much is "seed capital?" Or, rather, how much do you think is seed capital? |
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// I felt that the œB would be an excellent place to get some honest marketing feedback. // |
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I'm not sure I like the idea of using the halfbakery to get feedback on an existing product. And I'm definitely not comfortable with people using the halfbakery to raise funds for development of their existing designs. |
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My apologies for the poor choice of wording above, I am NOT trying to market this idea here. It is also not my intention to solicit any funds on the halfbakery. The question was asked, and I addressed it. |
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Contra waugsqueke, I think everyone else here likes to see and discuss new ideas, patented or not, commercially viable or not. |
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Your design certainly puts a lot more power into the cutting action, but I wonder if it gives less control over the direction of the cut? Or is that just because I am used to aiming things with the top (thumb-side) of my hand, not the bottom? |
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I am a little surprised no one has tried this before, but I imagine our patent search would have turned it up if someone had. |
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// Contra waugsqueke, I think everyone else here likes to see and discuss new ideas, patented or not, commercially viable or not. // |
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Well, I'm reassured to know you speak for everyone but me, Curry. I wasn't aware you had such a thumb on the pulse of the bakership. Somehow I doubt that is the case. |
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With all due respect, [waugs], this is not actually an existing product. It is something I've toyed around with and have produced a somewhat decent prototype for in my own little garage shop and is, literally, Half-Baked. It was never my intention to abuse the forum, and I don't feel that I have. I am confident that we will continue to share general sentiments on most of the issues brought up for discussion here on the œB.
[DrCurry], the model that I have(crude as it is) seems to maneuver quite well. If developed fully, I feel that an optimum combination could be attained. My search revealed only examples of prior art including a four-bar linkage, but in conventional form. [link] There have been no applications which include a forward (acute) angled positioning of the handles, I would presume that this is because the situation limits the working range of motion that the design engineer has to contend with. It is my opinion that this is not an obstacle, as I can can think of several ways to compact this design and still leave adequate room for usable function. |
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